Title of Dissertation: ABSTRACT MODELING THE PULMONARY EFFECTS OF RESPIRATORY PROTECTIVE MASKS DURING PHYSICAL ACTIVITY Karen Marie Coyne, Doctor of Philosophy, 2001 Dissertation directed by: Professor Arthur T. Johnson Department of Biological Resources Engineering Current respirator design involves developing and testing a prototype, making modifications, and then re-testing until a suitable mask is obtained. If the physiological effects of the respirator could be modeled, design could proceed more rapidly. Such a model would be an important design tool that would provide valuable information on the potential physiological and psychological compatibility of a respirator with the wearer. The model would not eliminate the need for human testing, but would decrease the number of prototypes required, saving time and money. A successful model would be very complex because of the many factors to consider. And, because of the variability of human response to exercise, work, and respirator wear, the initial development of the model will include many assumptions that may limit the expected accuracy of the predictions. The goal of this research was to develop a model of the pulmonary effects of respirator wear during physical activity that would form the framework of a larger model that would include other factors as well. Empirical equations were developed that related oxygen consumption to physiological work rate, anaerobic threshold ' minute ventilation and tidal volume to oxygen consumption, and exhalation time to respiratory period. Respirator resistance and dead volume effects were quantified. The model was implemented in Visual BASIC. The model predicted oxygen consumption, minute ventilation, and tidal volume weJJ for a limited number of subjects exercising below 70% of maximal oxygen consumption. For three subjects wearing respirators and exercising at 80- 85%, the errors in the model parameters were greater than those of the original equations. As model equations were based on average responses, predictions for any one individual may have large errors. Model simulations of a subject exercising at five different work rates with and without a respirator showed that the model made rational predictions of the effects of a respirator on respiratory parameters. More data is needed to completely validate the model. These results showed that the model structure was valid and that overall the model was capable of making rational predictions of the average effects of respirator wear on pulmonary system parameters during physical activity. MODELING THE PULMONARY EFFECTS OF RESPIRATORY PROTECTIVE MASKS DURING PHYSICAL ACTIVITY by Karen Marie Coyne Dissertation submitted to the Faculty of the Graduate School of the University of Maryland, College Park in partial fulfillment of the requirements for the degree of Doctor of Philosophy 2001 Advisory Committee: Professor Arthur T. Johnson, Chair Professor Marc A. Rogers Professor Gerald Saidel Professor Adel Shirmohammadi Assistant Professor Paul Schreuders DEDICATION This dissertation is dedicated to my parents, Thomas L. and the late M. Eleanor Coyne, with thanks for their love, encouragement, and support. 11 ACKNOWLEDGEMENTS There were many people who aided in the completion of this degree. r would like to thank my advisor, Dr. Arthur Johnson, for all his encouragement, support, and advice along the way. I am grateful to my other committee members, Dr. Marc Rogers, Dr. Gerald Saidel , Dr. Paul Schreuders, and Dr. Adel Shirmohammadi, for their advice and guidance with this research. I would like to thank my subjects for volunteering for my study and Mr. William Scott for helping with all the testing. r would like to thank the staff of the ENBE department for working behind the scenes to see that I received my paychecks, got my numerous forms completed, and made all the deadlines. My thanks to my fellow graduate students for their moral support, friendship, and pep talks. A special thanks to my great friend Ellen DeRico for being there over the years through the good times and the bad, for laughing with me and crying with me, and for sharing the many frustrations (dam text boxes!) involved in pursuing two degrees. And finally, my thanks to my family for their love, moral and financial support, and patience especially over the last few months. Thanks to my brothers, Kevin and Patrick, for scanning documents and typing references and to my Dad for playing chauffeur. Thanks to my nephew, Andrew, and my niece, Carly, for their hugs and smiles. A special thanks to Carly, for helping me with my "homework" even though we weren't in the same grade. Thanks for reminding me that learning is supposed to be fun. Ill TABLE OF CONTENTS Dedication Acknowledgements List of Tables List of Figures Introduction Review of Literature Model Development Problem Formulation Factor Specification Data Collection System Characterization and Mathematical Description Model Formulation Calibration Validation Methods of Validation Qualitative Analysis Quantitative Analysis Respiratory System Background Respiration and Physical Activity External Work Muscular Efficiency Efficiency Studies Equations Relating Efficiency to External Work Rate Physiological Work Rate Oxygen Consumption Slow Component of Oxygen Consumption Steady-State Oxygen Consumption Effects of Age and Training Anaerobic Threshold Minute Ventilation Factors That Affect Minute Ventilation Tidal Volume Exhalation and Inhalation Times Effect of Inspiratory and Expiratory Loading Oxygen Deficit Respiratory Work Rate Respiratory Work Rate Model Waveshapes Variable Lung Volume Maximum Expiratory Flow Effect of Waveshape on Respiratory Work Rate iv I I I I I ii I I iii I viii xii l 4 I I 5 I 7 I 8 I 9 I I 9 I I 10 11 12 14 14 15 19 21 22 28 31 34 35 42 43 49 51 52 58 60 61 62 65 67 68 71 72 72 73 73 Waveform Transistion Respiratory Protective Masks Physical Characteristics Resistance Dead Volume Mass and Load Placement Objectives Equipment Other Factors Variability Anxiety Hypoventilation Experimental Testing Treadmill Gas Collection System Respiratory Protective Masks Heart Rate Monitor Software Procedure Structure of the Model Experimental Testing Subject Information Determining Steady-State Minute Ventilation and Tidal Volume Targeted Work Rates Evaluation of Oxygen Drift and Subject Variability Steady-State Values Development of Equations External Work Rate Efficiency as a Function of External Work Rate Physiological Work Rate Required Oxygen Consumption Anaerobic Threshold Minute Ventilation as a Function of Oxygen Consumption Determining VEmax Tidal Volume as a Function of Oxygen Consumption Determining VTmax as a Function of V 02max The Effects of Resistance on Minute Ventilation and Tidal Volume Change in Minute Ventilation with Dead Space Change in Tidal Volume with Dead Space Oxygen Consumption as a Function of Minute Ventilation Oxygen Consumption as a Function of Tidal Volume Actual Oxygen Consumption Oxygen Deficit Performance Time Respiratory Rate and Respiratory Period V 74 76 76 76 82 84 85 85 85 86 87 88 88 88 88 90 90 91 92 92 92 94 96 96 96 96 97 98 98 99 99 101 102 103 104 104 105 105 106 107 108 108 108 109 109 Exhalation Time as a Function of Respiratory Period Breathing Waveform Based on Work Rate Respiratory Work Rate Implementing and Evaluating the Model Model Equations Subject Simulations Mask I No Mask Simulations Results and Discussion Structure of the Model Experimental Testing Subject Demographics Determining Steady-State Minute Ventilation and Tidal Volume Evaluation of Oxygen Drift and Subject Variability Steady-State Values Development of Equations External Work Rate Efficiency as a Function of External Work Rate Physiological Work Rate Oxygen Consumption Anaerobic Threshold Minute Ventilation as a Function of Oxygen Consumption Determining Vemax Tidal Volume as a Function of Oxygen Consumption Maximum VT as a Function of Vo2max Summary of Tidal Volume as a Function of Oxygen Consumption The Effects of Resistance on Minute Ventilation and Tidal Volume Change in Minute Ventilation with Dead Space Change in Tidal Volume with Dead Space Oxygen Consumption as a Function of Minute Ventilation Oxygen Consumption as a Function of Tidal Volume Actual Oxygen Consumption Oxygen Deficit Performance Time Respiratory Rate and Respiratory Period Exhalation and Inhalation Times Breathing Waveform Based on Work Rate Respiratory Work Rate Implementing and Evaluating the Model Model Equations Subject Simulations Mask I No Mask Simulations Summary of Model Evaluation Conclusions Suggestions for Further Study Appendices vi 109 110 110 111 111 112 114 115 115 119 119 120 121 123 125 129 129 140 141 148 156 165 171 180 182 185 195 204 211 213 218 218 219 220 221 225 226 227 228 228 245 263 265 267 269 Appendix A Human Subjects Protocol Appendix B Additional Figures Appendix C Data Appendix D Program Listing and Simulation Bibliography Vil 269 289 353 441 480 -- LIST OF TABLES 1. Gross efficiencies at four work rates and four pedaling rates. 2. Percent changes in minute ventilation, respiratory rate, and tidal volume from the low to high resistance conditions. 3. Demographic information for the eight subjects in the current study. 4. Work intensities for each of the eight subjects in the current study expressed as %Vo2max· 5. Oxygen consumption values (Umin) for subject 145 during three repeated tests of the standard respirator condition. 6. Steady state minute ventilation (Us) for stages one to five for each of the three respirator conditions. 7. Steady state tidal volume (L) for stages one to five for each of the three respirator conditions. 8. Summary of the equations used in the model. 9. Linear equations obtained from regressing AT%, AT, and V 02max-AT difference (Diff) on relative and absolute oxygen consumption. 10. Multiple regression equations obtained from stepwise regression of AT% AT, and V ozmax-AT difference (Diff) on age, height, mass (WT), BMI, and V 02max in relative and absolute terms. 11. Results from statistical tests to evaluate competing models. 12. Standard error ratio, bias, mean bias, and correlation coefficient for the linear, quadratic, exponential, and power models. 13. Standard error ratio, bias, mean bias, and correlation coefficient for the linear, quadratic, exponential, and power models fit to the % VTmax and % V 02max data. 14. Standard error ratio and correlation coefficient for steady-state minute ventilation and tidal volume regressed on inhalation and exhalation resistance for each of the stages. VIIJ 32 78 120 120 122 123 124 126 148 149 149 161 174 191 15. Changes in minute ventilation with external dead volume (L) at rest and during light and heavy exercise. 196 16. Changes in tidal volume with external dead volume (L) at rest and during light and heavy exercise. 204 17. Demographic data for three validation subjects. 228 18. Treadmill speeds and grades for the five stages. 228 19. Percent changes in minute ventilation for subjects exercising at 65-70% of Vo2max· 244 20. Subject 001 V 02max test. 354 21. Subject 002 Vo2max test. 355 22. Subject 023 V 02max test. 356 23. Subject 145 Vo2max test. 357 24. Subject 173 V 02max test. 358 25. Subject 214 Vo2max test. 359 26. Subject 221 V 02max test. 360 27. Subject 224 Vo2max test. 361 28. Subject 230 V 02max test. 362 29. Subject 231 V 02max test. 363 30. Subject 001 levels determination teS1. 364 31. Subject 002 levels determination test. 365 32. Subject 023 levels determination test. 367 33. Subject 145 levels detennination test. 369 34. Subject 173 levels detennination test. 371 35. Subject 214 levels detennination test. 373 ix b::r 36. Subject 221 levels determination test. 3 7. Subject 224 levels determination test. 38. Subject 230 levels determination test. 39. Subject 231 levels determination test. 40. Subject 001 condition A. 41. Subject 002 condition A. 42. Subject 023 condition A. 43. Subject 145 condition A. 44. Subject 173 condition A. 45. Subject 214 condition A. 46. Subject 221 condition A. 4 7. Subject 224 condition A. 48. Subject 230 condition A. 49. Subject 231 condition A. 50. Subject 001 condition B. 51. Subject 002 condition B. 52. Subject 023 condition B. 53. Subject 145 condition B. 54. Subject 173 condition B. 55. Subject 214 condition B. 56. Subject 221 condition B. 57. Subject 231 condition B. 58. Subject 001 condition C. X 375 377 379 381 383 385 386 388 390 392 394 396 398 400 402 404 406 407 409 411 413 416 419 59. Subject 002 condition C. 60. Subject 023 condition C. 61. Subject 145 condition C. 62. Subject 173 condition C. 63. Subject 214 condition C. 64. Subject 221 condition C. 65. Subject 231 condition C. 66. Data from three validation subjects before model changes. 67. Data from three validation subjects after model changes. 68. Data from inhalation/ exhalation study subjects. 69. Model simulation of no mask condition. 70. Model simulation of mask condition. 71. The first output file from the model showing the initial parameter values. 72. The second file generated by the model showing the results of the simulation. xi 421 423 425 427 430 432 434 436 437 438 439 440 477 478 LIST OF FIGURES 1. Flowchart of the model of the effects of a respirator on the pulmonary system during physical activity. 116 2. Efficiencies from three studies plotted against external work rate and the equations developed by Johnson (1992). 130 3. Best fit line through efficiencies for work rates of 10- 140 W. 132 4. Intersection of the new regression line through the Johnson (1992) equations. 134 5. Data plotted against the new set of efficiency equations. 135 6. Negative efficiencies plotted with the Johnson (1992) regression lines. 137 7. Negative efficiencies plotted with the new regression lines. 138 8. Efficiency data from the literature plotted with the new regression lines. 139 9. Calibration data and the zero-intercept regression line. 143 10. Validation data and the regression line. 145 11. Data from a validation study plotted along the regression line for the zero-intercept model. 147 12. Relative anaerobic threshold plotted against maximal oxygen consumption. Shown is the best fit line. 153 13. Validation data shown with the original data and the best fit line. 154 14. Steady-state minute ventilation versus oxygen consumption obtained during the levels detennination session for subject 214. 157 15. Steady-state minute ventilation versus oxygen consumption obtained during the levels detennination session for subject 231. 158 16. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for all subjects combined. 160 xii 17. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for a11 subjects combined. Shown is the best-fit quadratic model. 163 18. Validation data from two subjects plotted against the quadratic model relating percent of maximum minute ventilation to percent of maximum oxygen consumption. 164 19. Calibration data for maximum minute ventilation versus maximum oxygen consumption. Shown is the best-fit line. 166 20. Validation data for maximum minute ventilation versus maximum oxygen consumption. Shown is the best-fit line. 168 21. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 001. 172 22. Steady-state tidal volume versus oxygen consumption obtained during the Jeve]s determination session for subject 023. 173 23. Data pooled from the eight subjects who completed the current study. 175 24. Linear mode] fit to the pooled data from the eight subjects who completed the current study. 177 25. Validation data from subjects 224 and 230 plotted with the linear model. 179 26. Linear equation fit to the calibration data. 181 27. Linear equation fit to the validation data. 183 28. The intercept coefficients across work rates for the equations relating change in minute ventilation to inhalation and exhalation resistance. 187 29. The resistance slope coefficients across work rates for the equations relating change in minute ventilation to inhalation and exhalation resistance. 188 30. The intercept coefficients across work rates for the equations relating change in minute ventilation to inhalation and exhalation resistance. 189 31. The resistance slope coefficients across work rates for the equations relating change in minute ventilation to inhalation and exhalation resistance. 190 xiii 32. The change in minute ventilation with added dead volume for resting subjects. 33. The change in minute ventilation with added dead volume for lightly exercising subjects. 197 199 34. The change in tidal volume with added dead volume for resting subjects. 205 35. The change in tidal volume with added dead volume for lightly exercising subjects. 36. Oxygen consumption and minute ventilation from the levels determination session. Shown is the best fit line. 37. Validation data plotted against the best-fit line from regression of oxygen consumption against minute ventilation. 38. Oxygen consumption and tidal volume data from the levels determination session. Shown is the best-fit line. 39. Validation data plotted against the best-fit line from regression of oxygen consumption against tidal volume. 40. Exhalation time and respiratory period calibration data. Shown is the best-fit line. 41 . Exhalation time and respiratory period validation data plotted with the linear regression line obtained from the calibration data. 42. Oxygen consumption calculated by the model compared to measured oxygen consumption. 43. Minute ventilation calculated by the model compared to measured minute ventilation. 44. Tidal volume calculated by the model compared to measured tidal 207 212 214 216 217 222 224 230 231 volume. 232 45. Required oxygen consumption and physiological work rate. 234 46. Oxygen consumption calculated by the model compared to measured oxygen consumption after changes to the model. 236 47. Minute ventilation calculated by the model compared to measured minute ventilation after changes to the model. 237 XIV 48. Tidal volume calculated by the model compared to measured tidal volume after changes to the model. 239 49. Oxygen consumption calculated by the model compared to measured oxygen consumption for subjects who completed a study on inhalation and exhalation resistance. 240 50. Minute ventilation calculated by the model compared to measured oxygen consumption for subjects who completed a study on inhalation and exhalation resistance. 241 51. Tidal volume calculated by the model compared to measured oxygen consumption for subjects who completed a study on inhalation and exhalation resistance. 52. Minute ventilation from model simulation. 53. Tidal volume from model simulation. 54. Oxygen consumption from model simulation. 55. Respiratory rate from model simulation. 56. Inhalation time from model simulation. 57. Exhalation time from model simulation. 58. Inspiratory work rate from model simulation. 59. Expiratory work rate from model simulation. 60. Inspiratory work from model simulation. 61. Expiratory work from model simulation. 62. Total respiratory work from model simulation. 63. Total respiratory work rate from model simulation. 64. First test of respirator condition A for subject 145. 65. Second test of respirator condition A for subject 145. 66. Third test of respirator condition A for subject 145. xv 242 246 247 248 249 250 251 252 253 254 255 256 257 290 291 292 67. Regression equation fit to last four minutes of data for stage 5 of the first test of respirator condition A for subject 145. 293 68. Regression equation fit to last four minutes of data for stage 5 of the first test of respirator condition A for subject 145. 294 69. Regression equation fit to last four minutes of data for stage 5 of the first test of respirator condition A for subject 145. 294 70. Calibration data and the regression line. 296 71. Residuals for the zero-intercept model relating oxygen consumption to physiological work rate. 291 72. Residuals for linear regression of anaerobic threshold (mL) against maximal oxygen consumption. 298 73. Residuals for linear regression of anaerobic threshold (L) against maximal oxygen consumption. 299 74. Residuals for multiple regression of anaerobic threshold (mL) versus mass. 300 75. Residuals for multiple regression of anaerobic threshold (mL) versus maximal oxygen consumption. 301 76. Residuals for multiple regression of anaerobic threshold (L) versus mass. 302 77. Residuals for multiple regression of anaerobic threshold (L) versus maximal oxygen consumption. 303 78. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 001. 304 79. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 002. 305 80. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 023. 306 81. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 145. 307 xvi 82. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 173. 83. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 221. 84. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 001. 85. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 002. 86. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 023 . 87. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 145. 88. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 173. 89. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 214. 308 309 310 311 312 313 314 315 90. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 221. 316 91. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 231 . 317 92. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for all subjects combined. Shown is the best-fit linear model. 318 93. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for all subjects combined. Shown is the best-fit exponential model. 319 xvii 94. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for all subjects combined. Shown is the best-fit power model. 95. Residuals of percent of maximum minute ventilation of the validation data. 96. Maximum minute ventilation and maximum oxygen consumption data from the current study. Shown is the best fit line. 97. Residuals of maximum minute ventilation for the calibration data. 98. Steady-state tidal volume versus oxygen consumption obtained during the levels detennination session for subject 002. 99. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 145. 100. Steady-state tidal volume versus oxygen consumption obtained during the levels detennination session for subject 173. l O 1. Steady-state tidal volume versus oxygen consumption obtained during the levels detennination session for subject 214. 102. Steady-state tidal volume versus oxygen consumption obtained during the levels detennination session for subject 221. 103. Steady-state tidal volume versus oxygen consumption obtained during the levels detennination session for subject 231. 104. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 001. 320 321 322 323 324 325 326 327 328 329 330 105. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels detennination session for subject 002. 331 106. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 023. 332 xvm 107. Percent o~ maxim~m tidal. volume versus perce_nt ~f maximum oxygen consumpt10n obtamed dunng the levels determmat10n session for subject 145. 108. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 173. 333 334 109. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 214. 335 110. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 221. 111 . Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for 336 subject 231. 337 112. Quadratic model fit to the pooled data from the eight subjects who completed the current study. 338 113. Exponential model fit to the pooled data from the eight subjects who completed the current study. 339 114. Power model fit to the pooled data from the eight subjects who completed the current study. 340 115. Residuals of %VTmax for the two validation subjects. 341 116. Residuals for V Tmax as a function of V 02max· 342 117. Residuals from the change in minute ventilation with added dead volume for resting subjects. 343 118. Residuals from the change in minute ventilation with added dead volume for lightly exercising subjects. 344 119. Residuals from the change in minute ventilation with added dead volume for subjects lightly exercising at 30% Vo2max· 345 120. Residuals for the prediction of changes in tidal volume as a function of dead volume for resting subjects. 346 xix 121 . Residuals for the prediction of changes in tidal volume as a function of dead volume for subjects lightly exercising. 122. Residuals for the change in tidal volume as a function of dead volume and work intensity. 347 348 123. Residuals of oxygen consumption from regression of oxygen consumption on minute ventilation. 349 124. Residuals from linear regression of oxygen consumption on tidal volume. 125. Exhalation time and respiratory rate calibration data. 126. Exhalation time residuals from linear regression on the calibration 350 351 data. 352 127. The form "Main" that is displayed once the program is run . 466 128. The form for setting the physiological inputs of the model. 467 129. The form for setting the general parameters of the model. 468 130. The form for changing the respiratory parameters in the model. 469 13 l. The form for setting the thermal parameters in the model. 4 70 132. The form for selecting the respirator worn by the subject in the model. 471 133. Text boxes displayed when "Other" respirator is selected. 472 134. The form for setting the test conditions in the model. 473 135. The form for setting the test parameters when treadmill activity is selected. 474 136. The main form after a simulation has been run with the default parameters. 475 137. The main form after a simulation is run with the default values and the U.S . Army M40 respirator. 479 xx INTRODUCTION The need to protect workers from the inhalation of airborne contaminants has been recognized for many centuries. In 77 AD, Pliny the Elder wrote about red lead refiners wearing animal bladders to avoid breathing the lead dust (Roach, 1992). People such as Leonardo da Vinci (1452 - 1519) and Bernardino Ramazzini (1633 _ 1714) recognized also the need for respiratory protection (Rajhans and Blackwell , 1985). However, it wasn't until the 1800s and the industrial revolution that significant advances were made. In 1814, the "precursor to the modem day air- purifying respirator was developed" and in 1825, John Roberts developed a smoke filter for firefighters (Rajhans and Blackwell, 1985). In 1910, the Mine Enforcement Safety Administration (MESA), the predecessor of the Mine Safety and Health Administration (MSHA), began specifying regulations about the design and certification of different respiratory protection sold in the United States (Teresinski and Cheremisinoff, 1983). Design progressed rapidly during WWI when toxic gases were first used as a military weapon (Rajhans and Blackwell, 1985). In 1970, the concern for worker health came to the forefront. Former Labor Secretary Schultz testified before Congress that 14,500 Americans died and 2.2 million workers were disabled due to industrial accidents each year and, the u. s. Public Health Service stated that there were approximately 390,000 new cases of occupational diseases each year (Wang, 1993). The total monetary cost to the American public was estimated at $8 billion annually. Due to the large numbers of l workers killed or injured in industrial accidents every year, the Williams and Steiger Occupational Safety and Health Act (OSHA) was enacted in 1970. OSHA made employers responsible for the safety and health of their workers in the workplace. Engineering controls, such as increased ventilation, should be used first in protecting against the health risks from hazardous substances in the workplace. When these controls fail or are not technically feasible, personal protective equipment becomes necessary. Respirator masks are an essential component of the personal protective equipment and are used to protect workers against the inhalation of various contaminants - dust, mist, vapor, gas, and fume - that are found in the manufacture of chemicals, automobiles, steel, batteries, furniture, adhesives, and many other products. Additionally, there are individuals in small factories, offices and laboratories who are exposed to hazardous substances. Painters, soldiers, firefighters, miners, wood workers, construction workers, asbestos removal personnel and others must wear these masks. These workers perform activities of a physical nature at varying intensities while wearing respirators. Respirator design currently involves making a prototype and then testing it on humans. Adjustments to the respirator are made based on those tests and then a new prototype is made and is tested. This process continues until an adequate respirator is developed. A model that predicts the effects of a respirator on a person would allow respirator design to proceed more rapidly. Such a model would be an important design tool that would provide valuable information on the potential physiological and psychological compatibility of a respirator with the wearer. The model would not 2 eliminate the need for human testing, but would decrease the number of prototypes and testing required. Much time and money could be saved. There are thermal , metabolic, cardiovascular, respiratory, and psychological effects of respirator wear that need to be considered. Information on these effects is found in many different sources. A model would bring this information together and quantify these effects. The development of the model should also indicate areas where more information is necessary. A successful model would be very complex because of the many factors to consider. And, because of the variability of human response to exercise, work, and respirator wear, the initial development of the model will include many assumptions and this may limit the expected accuracy of the predictions. As more research is done that quantifies the effects of respirators on humans, this information should be included in the model. The purpose of this research was to develop a model that examined the effects of a respiratory protective mask on the pulmonary system during constant-rate exercise. This model could form the foundation for the larger model. If the intensity is not severe, constant-rate exercise will eventually result in a physiological steady- state (Wasserman et al. 1967; Poole and Richardson, 1997). Although a steady-state may not be possible physiologically, parameter values may still be detennined because these steady-state values will determine the rate of rise of the parameter and will be important when transient effects are included (Givoni and Goldman, 1972). 3 REVIEW OF LITERATURE When investigating the behavior of large-scale biological systems, it is often difficult to determine the effect changes in the system parameters have on the overall system. This difficulty may be due to the scale of the system or to problems collecting data. To overcome these problems, a mathematical model of the system may be developed. "[Mathematical models] provide a concise description of complex dynamic processes, indicate ways in which improved experimental design could be achieved and enable hypotheses to be tested (Finkelstein and Carson, 1985)." This approach has become more common in recent times due to the increase in the computational power of computers and the use of the systems approach to problem solving (Murthy et al., 1990). A model is a representation of a system in the real world. This system is analyzed to determine the important components and interactions between these components. These observations are then translated into a set of mathematical equations that describe the relationships between a system's behavior and its properties (Finkelstein and Carson, 1985). The resultant model is only an approximation of the whole system. The degree to which the mode] corresponds to the real-world system will depend on the purpose for which the model is designed. If a great degree of accuracy is required, the model necessarily becomes more complex and subsequently more difficult to evaluate. A Jess complex mode] would be simpler to evaluate, but would contain less information. 4 Developing mathematical models is not just a science, it is an art as well (Finkelstein and Carson, 1985; Murthy et al., 1990). Science is evident in the principles and equations used to formulate the model. However artisti·c asp t ' ec s such as creativity, ingenuity, intuition, and foresight are needed to make the model more than just a group of related equations. Because of the degree of personal choice in specifying a model, no two models will be the same. Model Development Model development depends in part on the type of model being used. Mathematical models may be classified as either empirical or theoretical, although there may be an overlap between the two (Murthy et al., 1990; Shirmohammadi et al., 200 I). A theoretical model results when well-established theories are used in determining the equations for a model. These models are called also physical or mechanistic models because they are based on the physical system. When the modeler fits equations to a set of data without considering the theory behind the relationship, an empirical model results. However, even when an empirical model is developed, it is important that the model not contradict established theory. So, an empirical model does have some theoretical basis. Theoretical or physical models have a broader appJication than empirical models because the theoretical models are not based on any one data set (Shinnohammadi et al, 200l). 5 In developing a model, it is important that a systematic approach be used. While various authors (Finkelstein and Carson, 1985; Hunt, 1999; McCuen, 1993; Murthy et al., 1990) use different nomenclature to describe the modeling process, the approach should involve the following steps: problem formulation, factor specification, data collection, assumption making, system characterization and mathematical description, model formulation, model calibration, and model validation. Because each of the stages is interrelated, the overall process is inherently iterative (Finkelstein and Carson, 1985). The techniques of aggregation, abstraction, and idealization must be employed during each stage of model development (Finkelstein and Carson, 1985). Aggregation involves grouping many common objects into one composite object. For example, the resistances of the arteries in the leg may be considered as a circuit of many single resistances or as one Jumped equivalent resistance. The choice would depend on the intended use of the model. Abstraction concerns the "degree to which only certain aspects of a system are included in a model (Finkelstein and Carson, 1985)." For instance, a model of stream health may include industrial pollution but not surface runoff. Approximation of system characteristics, or idealization, is also perfonned. An example of idealization would be assuming that all gases in a system are mixed instantaneously, even though this takes some finite time to occur. 6 Problem Formulation The problem formulation stage involves determining the objectives or purpose and scope of the model. It is important that the purpose be stated explicitly with as much detail as possible because the form of the model will depend on the purpose. "Thus the form of a model which is simply being used to describe some experimental test data is unlikely to be the same as one used for examining alternative hypotheses regarding the precise quantitative nature of the chemical and neural control of breathing or as that used for predicting the growth of a dysmature infant in response to a particular regime of feeding (Finkelstein and Carson, 1985)." Models may be developed to be descriptive, predictive, or explanatory (Finkelstein and Carson, 1985). Descriptive models attempt to find relationships between data. An example would be determining the equation relating the change in heart rate at increasing levels of exercise to the work rate. Predictive models are used to determine how a system will respond to a stimulus or change in the system, for example to predict the response of a person to a new drug. Finally, explanatory models provide insight into "the ways in which different features of system behavior and structure depend upon each other (Finkelstein and Carson, 1985)." Many models are a combination of the three. 7 Factor Specification At this stage it is important to list aII the important factors in the model. Simplification and elimination of some factors wiII occur later. Factors can be classified into three categories (Edwards and Hamson, 1990): constants, parameters ' and variables. Constants are factors that have fixed values (speed of light) and factors that are essentially the same in all cases of interest (acceleration due to gravity). Parameters have constant values for a particular problem but can change from problem to problem (Edwards and Hamson, 1990). In a fluid pumping model, the fluid density, the pipe diameters, and the pipe lengths would all be parameters. While these factors may vary from system to system, they are constant for the particular system being investigated. Variables will have values that change throughout the model. For the fluid pumping system, the velocity of the flow in the pipes would be a , variable because its value will change depending on factors such as the pipe diameter. After listing aII the possible factors, it is useful to group related factors together (Edwards and Hamson, 1990). This will help later when relationships between factors are formed. Each of the factors needs to be identified as a constant, parameter, or variable. Variables should then be divided into inputs and outputs. It is often easiest to first identify the constants and parameters and then the variables can be separated. To distinguish between input and output variables, it is helpful to look at the possible relationships between factors in each group. If a variable is a direct consequence of other variables, then that variable is an output (Edwards and Hamson, 1990). If a variable 's value is independent of aII other variables, then that variable is 8 an input to the model. To 1 t th 1· t h ~ h comp e e e 1s , eac 1actor s ould be assigned a variable name and units. Data Collection Data concerning and knowledge about the various factors involved in the model must be obtained. This information helps to define the scope of the model and may also cause the objectives to be altered if, for instance, there is not enough infonnation available. The required data may be available from various reference sources or new experiments may need to be conducted to obtain the data. Data are necessary for many stages of the modeling process. Plotted data can give insight into the mathematical form of a model or part of the model. Data are used in the calibration stage to approximate model parameters. They are used also in the validation stage to determine whether the model results agree adequately with real situations. System Characterization and Mathematical Description Because the model is only an approximation of the actual system, the modeler must decide which "features or characteristics of the system are relevant and significant for the goal in mind (Murthy et al, 1990)." The syStems approach requires first a functional and then a mathematical description of the biological processes and systems involved. The degree of detail included in a model is a compromise and is a part of the art aspect of modeling (Murthy et al., 1990). Including too much detail 9 results in a cumbersome model, while having too little detail gives an incomplete model. The relationships between the factors must next be specified. This involves deriving equations based on the gathered data. In many cases, such equations already exist. The modeler then must choose which equations fit the particular problem. In later stages, it may be necessary to return to this point to either include more infonnation or eliminate some factors. The end result of this stage is a collection of equations describing the procedures and processes that characterize the system. This collection is still far from being a model. It is during the next stage that these equations are combined and fanned into a model. Model Formulation An inductive, deductive, or pragmatic approach is used in fonnulating a mathematical model. The inductive approach involves observing system behavior and trying to model its characteristics. With this method, it is unlikely that the model parameters will have any physical significance. The deductive approach breaks a large system down into its component parts. Equations are developed for each of the Parts and for the interaction between the parts. A model is then formed from this system of equations (Barreto and Lefevre, 1984). The engineering approach is frequently the pragmatic one. That is, the model is determined with a definite purpose in mind (Barreto and Lefevre, 1984). Physiological models typically use the 10 deductive method because of the need to understand each of the parts and its relationship to the whole system. These approaches lead to empirical and theoretical models, or to combinations of the two. An empirical model results when an inductive approach is used. These models are typically viewed as "black boxes" because the resultant model is based only on the data, not on any theory or knowledge about the system. Empirical models are generally used only for descriptive purposes. The deductive approach leads to a theoretical model. This type of model is based on a priori knowledge about the system's structure and function. These models can be used for descriptive or predictive purposes. If the deductive approach is used, it is necessary to couple together the individual equations detennined in the system characterization stage. This process is not as simple as connecting the equations together. Care must be taken that the resultant model is not redundant and does not contain any incompatibilities such as two voltage sources connected in parallel (Barreto and Lefevre, 1984). Once the model has been fanned by relating the equations, the model must then be evaluated. Calibration The next step in the model development is to calibrate the model. This involves fitting the model to the data by adjusting the coefficients of the predictor, or independent, variables, so that accurate model output is obtained. The values of the 11 coefficients that give the best agreement between the model output and collected data are considered the optimal values (McCuen, 1993). In addition to the model itself, an objective function and a set of measured data are needed to calibrate the model. The objective function is an explicit mathematical function that specifies the optimal solution. Often, the least squares fit of a model is used as the objective function. Not all of the data should be used for calibrating the model. Some of the data should be saved for the next stage, model validation. Validation Validation consists of assessing whether the model is accurate and achieves the purpose for which it was designed. It is not possible to verify a model. "[Models] are essentially hypotheses, which are tested by subjecting them to crucial experiments designed to fals ify them and they are accepted to the extent that they are not falsified. (Finkelstein and Carson, 1985)." Validity concerns not just the final output, but the purpose, current theories, experimental test data, and other relevant knowledge (Finkelstein and Carson, 1985). When new theories are accepted and more experimental data are obtained, the model must be validated again. Validation of the model should take place throughout the development of the model, not just at the end. If any validation assessment indicates errors or inaccuracies in the model, it is necessary to return to the system characterization and fonnulation stages to make changes. It may even be necessary to modify the initial conceptual model (Finkelstein and Carson, 1985). 12 If it is not possible to validate the completed model, then model reduction must be used. This process begins by reviewing the initial conceptual model. Systematic model reduction is then accomplished by making assumptions based on physiological and mathematical principles (Finkelstein and Carson, 1985). Although it may seem better to start with this simplified model , "there is the danger, Particularly if the model is formulated simply on the basis of conforming to test response data, that it will lack physiological realism (Finkelstein and Carson, 1985).,, Determining the level of acceptance of the model and the degree to which the model replicates experimental data is subjective and often determined by the model purpose. Specifying the validation criteria explicitly will reduce this subjectivity (Cobelli et al. , 1984). The validity of a model is assessed using both internal and external criteria (Finkelstein and Carson, 1985). Internal criteria include consistency and algorithmic validity. The model is considered to be consistent if it does not have any mathematical , logical, or conceptual contradictions (Finkelstein and Carson, 1985; Cobelli et al. , 1984). Algorithmic validity requires that the algorithm be appropriate for the model and that it lead to accurate and logical solutions (Finkelstein and Carson, 1984; Cobelli et al. , 1984). External criteria include empirical, theoretical, pragmatic, and heuristic validity. Empirical and theoretical validity concern current knowledge. The model is empirically correct if it agrees with experimental data and is theoretically correct if it follows currently accepted theories. Pragmatic validity assesses whether or not the 13 objectives of the model have been met. Heuristic validity concerns detennining the .. . potential of the model for scientific explanation, discovery, and hypothesis testing (Finkelstein and Carson, 1985)." Methods of Validation No model should be used before it has been validated thoroughly. Validation consists of assessing whether the model is accurate and achieves the purpose for which it was designed. The model is subjected to input data over the range expected in the physical system to ensure that rational output is obtained. However, it is not possible to verify a model. The model is accepted to the extent that it cannot be proven incorrect. Both qualitative and quantitative methods are used to assess empirical and theoretical validity. Care must be taken when using any validation method. No single method should be used to deterrrune validity. A combination of qualitative and quantitative methods should be performed with the results being used in conjunction with knowledge, experience, and common sense to determine the validity of the model . Qualitative Analysis. Qualitative assessment consists primarily of observing the output response and comparing it to the expected response. Such parameters as magnitude and sign of the output should be checked to determine if they are 14 physiologically reasonable. Trends in the data, such as expected increases and decreases in the output should also be checked. Qualltitative Analysis. Quantitative evaluation generally involves goodness- of-fit tests to determine how closely the model output agrees with experimental data. The correlation coefficient, modified correlation coefficient, and standard error of estimate can all be used. In many cases, including time-dependent models, these goodness-of-fit criteria should be considered goodness-of-fit indices and not statistical measures because the underlying statistical assumptions, such as independent observations of the data, do not hold. The indices are still measures of Variance, but "they should not be used with standard tests of significance (McCuen, 1993)," However, Finkelstein and Carson (1985) argue that "due to the considerable physiological variation within the human population and the errors involved in measurements on the cardiovascular system, it is not appropriate to use integral of error squared or other similar perfonnance criteria in the comparison of this model With the real cardiovascular system." They recommend feature matching of the principle responses as the primary validation procedure. Murthy et al. (1990) state that goodness of fit tests can be used if they are adapted to the particular evaluation and have suggested specifying individual indices for each part of the model to be validated. 15 The approach of McCuen (1993) is more practical. Seven criteria are descri bed that should be considered when assessing a model's reliability; not all seven should be used with all models. These criteria are coefficient rationality, meeting the assumptions of the model, standard error of the estimate, correlation coeffi cient, model and relative bias, accuracy of fitted coefficients, and the analysis of variance (McCuen, 1993). Model rationality concerns both whether the output is reasonable and whether the coeffi cients provide an accurate relationship between the predictor and criterion variables. All coefficients should be rational in sign and magnitude. The intercept coeffi cient has the same units as the dependent variable so its rationality can be assessed directly. However, slope coefficients have units that are a function of both the independent variable and the dependent variable. Slope coefficients may be converted to dimensionless standardized partial regression coefficients: b.S . t . = - '-' I s y where: bi is the slope coefficient Si is the standard deviation of predictor variable i S is the standard deviation of the criterion variable. y (1) A standardized partial regression coefficient has an absolute value between one and d. tor variable If the absolute value zero, with one indicating an important pre ic · 16 exceeds one, then intercorrelations are significant and the coefficient is irrational. McCuen (1993) stated that an irrational model should be used with caution and should not be used beyond the range over which it was developed. The model bias is found by summing the differences between the model and experimental values. A positive bias means that the model consistently overestimates, while a negative bias indicates the opposite. Small biases are tolerable if other criteria are met. The t-test can be used to determine if model bias is significantly different from zero. The standard deviation is a measure of the spread of the data and the accuracy of the mean. To reduce the error variance, the criterion variable is related to the predictor variables. The goal is to provide an unbiased relationship that has a minimum sum square of errors. The error variance is the sum square of errors divided by the degrees of freedom. The standard error of estimate is the square root of the error variance. If the Se is less than the Sy of the population, then the model provides a better estimate of the criterion variable than the mean. The ratio, SefSy, is used to determine if any improvement has occurred. If the ratio is near zero, a significant improvement has occurred. Conversely, if the ratio nears one, no improvement has occurred. The correlation coefficient is a measure of the degree of the relationship between a criterion and predictor variable; it does not specify the relationship. The square of the correlation coefficient is a measure of the amount of variance of the criterion variable explained by the predictor variable. McCuen (1993) states that the 17 standard error of estimate is a better measure of goodness of fit than correlation coefficient because the standard error of estimate has the following advantages: it has the same units as the criterion variable, the degrees of freedom are accounted for Properly, and it is valid for nonlinear and linear models. Model coefficient accuracy can be assessed by examining the standard error of the regression coefficient. McCuen (1993) has found from experience that the coefficient is of questionable accuracy if the ratio Se(bi)/bi exceeds 0.3 to 0.4. The sum of the residuals is examined to determine if there is a bias in the model. If the sum differs from zero, a bias exists. While R2 is the amount of Variation in the criterion variable explained by the predictor variable, the residuals are the variation not explained by the predictor variables. The principle of least squares assumes a constant error variance. A plot of the residuals versus the independent variable should be obtained to detennine if there is any pattern to the residuals. If a pattern exists then the residuals do not have a constant variance. 18 Respiratory System Background The main function of the respiratory system is to provide oxygen to the tissues and remove carbon dioxide. This is accomplished through external and internal respiration. External respiration occurs in the lungs whereas internal respiration takes place at the tissue level. External respiration begins as the diaphragm and external intercosta1 muscles contract, expanding the chest cavity and creating a resultant pressure that is lower than atmospheric (Jensen and Schultz,1970). Due to the lower pressure inside the chest cavity, air rushes into the lungs to equalize pressure. Air is returned to the atmosphere with the subsequent relaxation of the diaphragm and intercosta1 muscles that increases the pressure within the chest cavity and forces the air out of the body. Thus, at rest, inhalation is considered active whereas exhalation is passive. During exercise, exhalation also becomes active requiring the internal intercostal and abdominal muscles to contract and further reduce the size of the thorax. The air that is forced into the lungs first enters either through the nose or the mouth and then passes to the pharynx. From the pharynx, the air passes the larynx and enters into the trachea, the start of the tracheobronchia1 tree. From this point on, the air flow will divide among a set of dichotomously branching tubes in both the left and right Jobes of the lung. At each branching, the diameter of the tubes becomes smaller, although the total cross-sectional area increases. From the original branchings off the trachea, the main stem bronchi, through the bronchioles, and into 19 the terminal bronchioles, the air will eventually reach the alveoli. The alveoli are tiny, thin-walled sacs that lie among a bed of capillaries, small diameter blood conduits. It is in the alveoli that gas exchange with the blood occurs. The inspired air canies oxygen to the alveoli and the blood while the expired air carries carbon dioxide from the blood and delivers it to the atmosphere. The respiratory muscles are controlled by respiratory centers located in the medulla, a part of the autonomic nervous system. As such, breathing is involuntary. An individual may hold his or her breath for a while, but eventually, the person wiU be forced to take a breath. Factors influencing the control of respiration include: muscular activity, emotions, carbon dioxide concentration, oxygen deficiency, and heart rate (Jensen and Schultz, 1970). The amount of air that is inhaled or exhaled during each breath is termed the tidal volume. In an average, healthy, resting human, this value is approximately 500 mL (Johnson, 1991). The typical respiration rate of the same typical human is approximately 17 breaths per minute (Johnson, 1991). The minute volume, the amount of air inspired or expired in one minute, is the product of the tidal volume and the respiration rate. 20 Respiration and Physical Activity Physical activity begins at some external work rate. This work rate requires a certain amount of internal or physiological work. The increased amount of oxygen required by the body is dependent on the physiological work rate. In response to the increased oxygen consumption, minute volume rises immediately. It then rises at a slower rate to a steady-state value (Johnson, 1991). The increase is exponential with a time constant of 65-75 seconds (Whipp, 1981). More capillaries open in the Jung increasing the area for gas diffusion and thus the diffusing capacity of carbon dioxide and oxygen (Berne and Levy, 1988). At a constant moderate rate of exercise below the anaerobic threshold, the minute volume will level off at a steady-state value (Johnson, 1991 ). Above the anaerobic threshold, a steady state may not be achieved. Tidal volume and respiratory rate also increase. The inhalation and exhalation times shorten. Wearing a respirator has been shown to affect the pulmonary response to exercise (Johnson et al., 1999). Hypoventilation can occur with a decreased oxygen consumption. The effects of the respirator need to be considered. 21 External Work External work is the amount of mechanical work being accomplished. It is equal to the product of force and distance. Work rate, or power, is the work divided by the time to accomplish that work. Work is expressed in units of N·m whi le work rate is expressed in N·m/s, or Watts (W). So, the external work accomplished by a person with a mass of 70 kg who climbs a set of stairs (total distance: 3 m) is: m Wext = (70kg)(9.8-2 )(3m) = 2058 N · m s (2) The work rate would depend on how fast the person climbed the stairs. If the person took 3 seconds to ascend the stairs then the external work rate would be 686 W. Taking ten minutes to climb the stairs would result in an external work rate of 3.43 W. So, the time to accomplish the task is an important factor in how hard the person is working. Therefore, it is common to use external work rate instead of external work to make comparisons between activities. Physiological studies often use activities where it is easy to determine the external work rate of a subject. These activities include walking or running on a treadmill, cranking an ann ergometer, pedaling a cycle ergometer, or stepping up and down a block. The work rate when using a bicycle ergometer is (Robergs and Roberts, 1997): 22 distance cadence· load· ----. g WR = revolution ext 60 where: WRexi, external work rate, W cadence, rev/min load, kg distance/revolution, m g is the acceleration due to gravity, m/s2 60 is a conversion from min to sec For a Body Guard or Monark ergometer, the distance/revolution is 6 m, while for a Tunturi it is 3 m (Robergs and Roberts, 1997). The work rate of stepping (W) is: WR ext = h seep • mass . n step • g where: hstep, height of the step, m mass, the mass of the person, kg nstep, number of steps, dimensionless g, acceleration due to gravity, mls2 (4) The work rate of walking is more difficult to assess. In fact, Wasserman et al. (1999) stated that "probably the greatest disadvantage of the treadmill is the difficulty in quantifying the work rate." The external work rate of walking or running on level 23 (3) ground is usuaJly taken to be zero. It's not that work is not being done. Work is done as the body is raised and lowered, but the positive and negative work are usually assumed to offset one another. Webb et al. (1988) perfonned a study to detennine if the work rate during walking was actually zero. Five male and five female subjects wore a suit calorimeter in a respiration chamber while walking on a level treadmi11 for 70 to 90 min at speeds of 0.69, 1.28, and 1.86 mis. The suit calorimeter consisted of a mesh of water-fiJled tubes that covered the body. The amount of heat transferred to the water in the suit was determined. Subjects also pedaled a bike ergometer for 70 to 90 minutes against loads of 53 and 92 W. For cycling, the energy expenditure calculated from respiratory gas exchange equaled the heat produced plus the external work rate on the bike. However, the heat balance for walking showed that the energy expenditure did not equal the heat produced. This indicated that external work was done in walking. The amount of work done during walking increased with walking speed and was found to be an average of 12% of the transformed energy. The authors concluded that work was done bending the sole of the shoe and in other interactions between the foot and the treadmill surface. The work of Webb et al. (1988) was continued by Nagle et al. (1990). These investigators had ten male subjects walk on a treadmill while wearing a suit calorimeter. Subjects walked at 1.5 mis at grades of IO, 5, O, -5, and 10%. Similar to their previous work (Webb et al., 1988), a non-thermal energy term was found at all grades. So, there is physical work done in grade walking as weJl as level walking that 24 cannot be accounted for by external work or heat produced. This non-thennal tenn was significant at grades of 0, 5, and 10% but not at the negative grades On a · verage, this non-theimal energy tenn accounted for 6% of the transfonned energy, which is half of that reported previously (Webb et al., 1988). While Webb et al. (1988) proposed that the energy was expended in the compression of the heal of the shoe and in bending the sole, the current investigators offered a different explanation. They theorized that a portion of the energy externalized during the positive phase of walking is only partiaIIy recovered as heat energy during the negative phase (Nagle et al., 1990). The external work done in level walking was investigated also by SneIIen (1960). Three subjects walked on a level treadmiJJ in a climatic chamber for one hour. The air and waJJ temperatures were kept close to skin surface temperature so that heat loss through radiation and convection was kept to a minimum. Heat Jost through evaporation was calculated. The final heat balance showed that heat gained equaled heat Jost. The investigator detennined that level walking did not involve external work. It was noted in the article that there were errors in the measurements. Air and wall temperatures did not exactly match weighted skin temperature. Evaporation was detennined through weight Joss of the subject. Some of the water evaporated comes from the respiratory tract, but the heat of vaporization was detennined at average skin temperature. The different results obtained by Snellen 0 960) and Webb et al. (1988) and Nagle et al. 0990) may be due to technique. Webb et al. (1988) and Nagle et al. 25 (1990) used a suit calorimeter to measure the heat Joss by the subject. As the external work rate represented 6% of the energy, it is possible that this non-thermal term was not seen in the study done by Snellen (1960) because of the errors involved in the calculations of heat Joss and heat production. In fact, a study conducted by Johnson et al. (200Ia) that investigated the heat production in level and grade walking found that there was a difference between the metabolic rate and heat production. While a calorimeter was not used, subjects were thermally insulated from the environment by clothing that consisted of light underwear, a neoprene wet suit, military fatigues, sneakers, sock, two pairs of gloves, a full-facepiece respirator mask, and a neoprene hood. This was done to decrease the heat Joss by conduction and evaporation. So, when heat loss and heat gain are monitored carefully, it appears that there is indeed work done in level walking. A number of approaches have been used to deal with the problem of determining external work during walking. Lakomy (1984) and Cheetham et al. (1986) have used an ergometer system that allows power to be determined during running. Givoni and Goldman (1972), Pandolf et al. (1977), and Aoyagi et al. (1995) provided equations for calculating external work rate. Other authors (Groot et al., 1994) have filmed various activities and determined the work performed. A treadmill ergometer system was developed by Lakomy (1984). The subject ran on a non-motorized treadmill to which a small generator was attached. The generator gave a voltage proportional to the belt speed. A transducer was mounted at the back of the treadmill. The subject wore a harness around the waist that attached 26 to the transducer. The harness held the subject in place and ensured that the force measured by the transducer was the same as the force applied horizontally on the belt. Instantaneous power was found from the treadmill speed and the force applied to the transducer. Similar types of systems have been used for rowing (Hagerman and Lee, 1971) and swimming (Toussaint et al., 1990). Equations for external work were presented by Givoni and Goldman (1972) and Aoyagi et al. (1995). The equation provided by Givoni and Goldman (1972) was: WR = 0098·m ·v ·G ext · t where: WRexi, external work rate, W me, total mass, kg v, velocity, mis G, grade, percent (5) The term 0.098 is the acceleration due to gravity divided by 100. So, equation (5) may be written as: G WR =m ·g·v·- exr t 100 The equation provided by Aoyagi et al. (1995) was: 3.6·m, -g· vsin0 WRext = __ _.:._A,.;;;.._-- D 27 (6) (7) where: WRex1, external work rate per area, kJ/(m2 h) 0, angle of inclination with respect to the vertical, (= arctan (G/100)), degrees If equation (7) is expressed in Watts, it becomes: WR 1 = m · g · v sin 0 ex t (8) where: WRexi is the external work rate, W The difference between equations 6 and 8 is the G/100 and sin 0 terms. These terms are equivalent for grades up to 25%. Other researchers (Groot et al., 1994) filmed subjects during exercise and then determined the individual joint moments and angular velocities. The joint power was found as the product of the joint moments and velocities. The sum of these joint powers reflected the external work rate for the task. MuscuJar Efficiency The amount of power input to a machine is greater than the power output. This is because machines are not JOO% efficient. Mechanical efficiency is the power output divided by the power input. Humans are also not 100% efficient. In physiology, mechanical efficiency is referred to as overall or gross efficiency. It is 28 found by dividing the external work rate by the physiological work rate. The physiological work rate, sometimes called the metabolic cost of exercise, is the internal energy required to produce external work. There are other definitions of efficiency encountered in the literature. There are net efficiency, work or apparent efficiency, delta efficiency, and activity specific efficiencies such as propelling efficiency for swimming. Net efficiency is external Work rate divided by the difference of physiological work rate and resting metabolic work rate (Fukunaga et al., I 986). The resting metabolic work rate, or basal metabolic rate, is the amount of energy required by the body for the chemical and metabolic processes required to sustain life. The work or apparent efficiency is found by dividing external work by the difference of physiological work rate and the energy expenditure during non-working conditions. The tenn work efficiency is used typica1Jy for bicycle exercise while apparent efficiency is used for treadmill walking or running (Stainbsy et al., 1980). Delta efficiency is the increment in work rate performed above the previous work rate divided by the increment in physiological work rate above the previous work rate (Fukunaga et al., 1986). Stainbsy et al. ( 1980) discussed the validity of base-line subtractions for determining efficiency. The authors indicated that there were differences between exercise efficiency and muscle efficiency. Muscle efficiency should be determined from the processes that provide and convert energy to work (Stainbsy et al., 1980). Exercise efficiency was the external work divided by the energy required to perform that work. 29 It was suggested (Stainbsy et al., 1980) that muscle efficiency be detennined as the product of phosphorylative coupling efficiency and contraction coupling efficiency. The energy for muscular contraction comes from the oxidation of nutrients. Part of this energy is saved in the ATP molecule. This process was tenned phosphorylative coupling. The phosphorylative coupling efficiency was found by dividing the free energy conserved as ATP by the free energy of oxidized foodstuff (Stainbsy et al., 1980). Some of the energy from the ATP was used to perfonn work and was tenned contraction coupling. Contraction coupling efficiency was calculated by dividing the external work accomplished by the free energy of ATP hydrolysis (Stainbsy et al., 1980). The authors argued against using base-line subtractions in detennining efficiency because the base line values have been found to change as exercise intensity increases and are thus invalid. They stated that gastrointestinal processes decreased, splanchnic metabolism increased, and energy required by the lungs increased with increasing work rate. Additionally, body temperature increases which then increases the metabolic rate. These factors all caused changes in the base-line values and, according to Stainbsy et al. (1980), precluded the use of efficiencies using base-line subtractions. The authors further stated that while none of the widely used and widely accepted efficiencies (gross, net, apparent, work, and delta) really represent muscle efficiency, there were no errors in using gross efficiency as long as it was referred to as exercise efficiency. 30 Gross efficiency depends on the work rate, type of work, and which muscles are used. There is a lot of error in the efficiency calculation due to human variability and the fact that external work rate alone does not determine efficiency. Muscular efficiency is influenced by the subject's coordination and familiarity with the activity being perfonned (Robergs and Roberts, 1997). Wasserman et al. (1999) found that experience in treadmill walking may lead to an increase in efficiency. Activities involving fine movements genera]]y have low efficiencies while activities such as running that involve gross movements and large muscle mass have higher efficiencies (Johnson, 1991). As the resting metabolic demands become a smaller proportion of overall energy requirements, gross efficiency approaches a maximum value of 20% (Johnson, 1991). Efficiency Studies Many studies have been perfonned that investigated the efficiency of various activities. Fukunaga et al. (1986) found that for college oarsmen, the gross efficiency of rowing in the external work rate range of 124 - 182 W was 17.5%. The efficiency of swimming in competitive male and female swimmers ranged from 5 to 9.5% (Toussaint et al., 1990). The authors found that as power output increased, gross efficiency increased also. Webb et al. (1988) investigated the work done by five males and five females during bicycle ergometer work at 53 and 92 W. Heat production was measured using 31 a suit calorimeter. Gross efficiency for the 53 Wand 92 W workloads were 13% and 17%, respectively. The effects of speed and work rate on muscular efficiency during steady-rate exercise on a bicycle ergometer were investigated (Gaesser and Brooks, 1975). Gross muscular efficiencies were reported at work rates of 33, 65, 98, 131 Wat pedaling rates of 40, 60, 80, and 100 rpm. Their results are shown in Table 1. They found that as pedaling frequency increased, efficiency decreased. Table 1. Gross efficiencies at four work rates and four pedaling rates. Efficiencies are d d d · · D t f G d B - reporte as mean + standar eviatwn. a a are rom aesser an rooks (1975). 33W 65W 98 131 - 40rpm 12.0± 0.3% 17.0 ± 0.3% 19.3 ± 0.2% 20.2 ± 0.4% 60rpm 12.1 ± 0.3% 16.6± 0.3% 19.2 ± 0.4% 20.4 ± 0.4% BO rpm 10.2±0.2% 14.8 ± 0.2% 17.6 ± 0.2% 18.8 ± 0.3% 100 rpm 7.6 ±0.3% 12.1 ± 0.3% 15.1 ± 0.2% 16.6±0.3% The physiological responses of nineteen subjects to arm, leg, and combined ann and leg ergometry at work rates of 49, 73.5, and 98 W was investigated by Eston and Brodie ( 1986). Physiological work rate was calculated. The average gross efficiencies for the work rates of 49, 73.5, and 98 W for arm ergometry were 11.8%±0.6%, 12.5%±1.20%, and 12.5%±1.20%. These efficiencies were significantly different from the leg and combined ann and leg efficiencies. For leg 32 ergometry the efficiencies were 13.5%±0.80%, 15.60%±1.40% 17.11%+1 20m h' , 7c_ . 70 w tle for the combined arm and leg ergometry the efficiencies were 12.90%±1.30% ' l5.20%±1.10%, and 16.8%±1.60%. All efficiencies are reported in order of increasing work rate. There were no statistically significant differences between the leg and combined arm and leg ergometry. Luhtanen et al. (1987) reported gross efficiencies for subjects on a bicycle ergometer. For work rates of 146±15, 190±4, 225±12, 254±11, and 283±17 w, the gross efficiencies were 19.7%±3.7%, 19.7%±2.8%, 18.9%±2.8%, 18.2%±2.8%, and 17.4±1.0%, respectively. On average, the efficiency of the subjects decreased as external work rate increased. Nagle et al. (1990) investigated the work done in grade walking on a treadmill. If the non-thennal energy term is ignored (an average of 6% of transformed energy), the efficiencies for walking at a speed of 1.5 mis at grades of 5, 10, -5, and -10% were 10.6%, 15.8%, -20%, and -48.8% respectively. Haembraeus et al. (1994) adapted the suit calorimeter used by Webb et al. (1988) and Nagle et al. (1990) so that the suit could be used for exercise intensities of 250W or higher. Unfortunately, external and internal work rates were reported only for two male subjects, one twenty-nine year old and one fifty-five year old. The fifty- five year old subject completed one trial on a bicycle at lOOW. The efficiency of the activity was 22%. The twenty-nine year old completed two bike sessions at 200 w and one at 100W. The efficiencies for these activities were 19.4%, 18.9%, and 15.2%. 33 The muscular efficiency of uphiJJ and downhi11 walking at a constant speed of I. 1 mis was investigated by Johnson et aJ. (2001a). The authors found that the efficiency of downhi11 walking was negative two times the efficiency of uphi11 walking. These results were supported by the work of Orsini and Passmore ( 1951 ), Pivamik and Sherman (1990), and Nagle et aJ. (1990). Hesser (1965) examined the efficiency of 10 ma]e and 10 females climbing up and down stairs at speeds of 88 steps/min and 160 steps/min. The author found that for the Jower speed, the ratio of oxygen cost of positive work to negative work was 8: 1. When the speed was increased, the ratio decreased to 5: 1. These results contrasted with those of Abbott et aJ. (1952) and Asmussen (1953) who found that for bicycJe ergometer work the ratio increased with speed. The fact that negative work in running or walking is more efficient than positive work is supported by Pimenta] et a]. (1982) and Davies et aJ. (1974). Equations Relating Efficiency to External Work Rate Johnson (1992) developed a series of equations relating gross muscular efficiency to external work rate. Maximum efficiency was assumed to be 20%. The equations were: WRCXI 17 = 200 (9) 17 = 0.05 + 0.00 l(WR exr -10) IO 5 WRext $140 (10) 34 17 = 0.18 + 0.0002(WR - 140) ext 17 = 0.2 where l) , muscular efficiency, dimensionless WRexr, external work rate, W Physiological Work Rate l40 $ WRext $ 240 (11) 240 $ WR ext ( 12) Physiological work rate is the internal energy required to produce external work. Physiological work rate is equal to the external work rate divided by the muscular efficiency. For steady-state exercise when there is no change in the body temperature and thus no change in the rate of heat stored, physiological work rate is the sum of the heat produced during exercise and the external work produced. If the external work is zero, then determining physiological work rate in the above way would give a physiological work rate of zero. If the person is resting, the Physiological work rate would equal the basal metabolic rate. However, if the person is running on level ground, the person has a physiological work rate much higher than basal metabolic rate. An alternative to calculating external work rate would be to use a look-up table that provides physiological work rates for walking, running, and other tasks. When a look-up table is used, it is important to consider the conditions under Which the values were obtained. Factors such as age, body mass, gender, and fitness level would be important. Tables of physiological work rates for leisure, work, and 35 military tasks can be found in many sources including Johnson (1992), Johnson (1991), and McArdle et al. (1996). The physiological work rate can also be calculated in another manner. Givoni and Goldman (1971) developed an empirical equation for predicting the metabolic energy cost of level and grade walking, with and without loads. The equation was found to apply to walking speeds of 0.7 mis to 2.5 mis at grades up to 25% and for running speeds from 2.22 mis to 4. 72 mis at grades up to 10% with loads up to 70 kg. The authors suggested empirical coefficients to modify the equation for different terrains, for load placement, and for very heavy work levels. The results showed a correlation of 0.95 between predicted and measured values. Pandolf et al. (1977) continued the work of Givoni and Goldman (1971) by adjusting the equation to make predictions for subjects who were standing or walking very slowly (less than 0.7 mis). The authors validated the equation with two studies. The first involved six males walking at speeds of 1.0, 0.8, 0.6, 0.4, and 0.2 mis while carrying loads of 32, 40, and 50 kg. In the second experiment, ten males stood while wearing backpacks that had masses of 0, 10, 30, and 50 kg. Good agreement was found between the empirical model and the experimental results. Myles and Saunders (1979) had nine male subjects walk on a treadmill with loads equal to 10% and 40% of body weight. They used the equation developed by Pandolf et al. ( 1977). Good agreement was found between the predicted and measured values. 36 Physiological work rate, or metabolic energy cost, can also be determined using either direct or indirect calorimetry. Direct calorimetry measures the amount of heat produced by the body. Indirect calorimetry relates the total metabolic heat production of the body to oxygen consumed and carbon dioxide produced. With direct calorimetry, the subject is placed typically in a thermally isolated chamber (Ferrannini , 1988) for periods of 24 hours or more. The heat lost through evaporation, radiation, conduction, and convection is measured. These chambers are expensive and are not common. A suit calorimeter was developed that enabled a subject to perform activities outside of a chamber (Webb et al., 1988; Nagle et al., 1990; Hambraeus et al., 1994). The use of indirect calorimetry began over two hundred years ago when Adair Crawford in England and Antoine Lavoisier in France proved that respiratory gas exchange represented combustion similar to that of a burning candle (Webb, 1991). The energy production results from converting nutrients (carbohydrate, fat and protein) into the chemical energy of ATP minus the energy used in the oxidation process (Ferrannini, 1988). Indirect calorimetry assumes that all of the oxygen consumed is used to oxidize fuel and that all the evolved carbon dioxide is recovered (Ferrannini, 1988). So, measuring oxygen consumed and carbon dioxide produced gives an estimate of the energy production of the body. Swyer (1991) has found that estimations of metabolic energy production made with indirect calorimetry agreed with direct calorimetry values for steady-state conditions if proper procedures were followed. 37 Many equations have been developed that relate the metabolism of nutrients to the oxygen equivalent of the metabolism. The equations are based on the same theory but differ in their assumptions and intended applications. These equations have been used by many investigators to estimate metabolic energy production. The theoretical Weir (1949) equation was based on the caloric equivalent of oxygen and carbon dioxide. The equation used total respiratory quotient which includes metabolism of carbohydrate, fat, and protein. Weir assumed that the total percentage of protein calories was between 10 and 14%. If this assumption held, the error in the equation was Jess than 0.2%. The equation was: kcal liberated = 3.9 + 1.IRQ LO 2 consumed where: RQ, total respiratory quotient, dimensionless (13) Garby and Astrup (1987) developed a theoretical equation based on the metabolism of carbohydrate and fat. Protein metabolism was assumed to be zero. Thus, the respiratory quotient used is termed the non-protein respiratory quotient. The equation was: 0 2 -eq. =A· NPRQ +B {14) where: 02 _ eq., energy equivalent of oxygen, J/L A, B, coefficients that depend on the amounts of carbohydrate and 38 fatconsumed,J/L NPRQ, non-protein respiratory quotient, dimensionless The most commonly used values for the coefficients A and Bin equation 14 were 4,940 J/L and 16,040 J/L, respectively (Garby and Astrup, 1987). A third theoretical equation was presented by Lusk (1928). The equation was: cal = 4.686 + 0.361 · (RER - 0. 707) L 0 2 consumed 0.293 (15) where: RER, respiratory exchange ratio, dimensionless The Weir (1949), Garby and Astrup (1987), and Lusk (1928) equations a]] determined the energy equivalent of oxygen. Physiological work rate was determined from these equations by multiplying the energy equivalent of oxygen by the oxygen consumption and converting units. The equations for predicting physiological work rate from the Weir, Garby and Astrup, and Lusk equations, respectively were: (4606RQ + 16329)V0 2 WRphys = 60 (16) (4940NPRQ + 16040)V02 WRphys = 60 (17) (5155RER + 15962)V02 WRphys = 60 (18) where: WRphys, physiological work rate, W 39 V 02, oxygen consumption, Umin Gagge and Nishi (1983) presented an equation for predicting metab 1. o 1c energy from oxygen consumption and carbon dioxide production: WR phys = (0.23RER + 0.77)(5.873)Vo2 (60) where: WRphys, physiological work rate, W RER, respiratory exchange ratio, dimensionless Vo2, oxygen consumption, Umin 5.873, energy equivalent of oxygen, W·hr/L (19) The authors recommended that the equation not be used for transient conditions. Putting their equation in the same fonnat as above yielded: WR = (4863RER + 16280)V02 phys 60 where: WRphys, physiological work rate, W RER, respiratory exchange ratio, dimensionless Vo2, oxygen consumption, Umin (20) The four equations (16 - 18, 20) have similar coefficients. Some of the equations used respiratory quotient while others used respiratory exchange ratio. 40 The respiratory quotient is defined as the ratio of the rate of carbon dioxide produced to the rate of oxygen consumed. The respiratory exchange ratio is defined as the ratio of the rate of carbon dioxide exhaled to the rate of oxygen consumed. So the difference is in the carbon dioxide term. RQ deals with cellular respiration and is used to calculate the caloric value of oxygen consumption. RER is related to external respiration and is an indication of the work intensity. RQ and RER can be considered to be equal except under the following conditions: metabolic acidosis, non-steady state conditions, hyperventilation, excess post-exercise oxygen consumption, and extremely heavy exercise (Robergs and Roberts, 1997; Johnson, 1991). The RQ cannot exceed 1.0 because the carbon dioxide produced by cells cannot exceed the oxygen consumed. However, when excess acid is produced (metabolic acidosis) such as during heavy exercise, the body produces increased levels of carbon dioxide separate from oxygen consumption due to buffering of the carbon dioxide. Because of the excess carbon dioxide produced, RER can exceed 1.0 under conditions of metabolic acidosis. Under non-steady state conditions, oxygen consumption has not had a chance to increase to levels that account for ATP produced during metabolism. Instead, the ATP comes from creatine phosphate hydrolysis and glycolysis. So, a lower metabolic intensity would be indicated during the transition than if the person had already achieved a steady state (Robergs and Roberts, 1997). During hyperventilation, the volume of carbon dioxide exhaled from the lung increases. This can occur without increases in oxygen consumption, so the RER may 41 , be increased. The RQ would remain the same because the carbon dioxide produced by the cells had not increased. Finally, after exercise, the amount of carbon dioxide exhaled decreases rapidly While the oxygen consumption remains elevated above resting levels. Thus, the RER may decrease below resting values (Robergs and Roberts, 1997). The actual physiological work rate can be Jess than the predicted when there are connections between a subject and the test apparatus other than, for example, the connection between the shoes and the treadmill belt. Wasserman et al. (1999) stated that railings, arrnboards, mouthpieces, blood pressure measuring devices, and steadying hands could all reduce the patient's metabolic requirement. The mass of shoes and stiffness of their soles may affect the physiological work rate (McArdle et al., 1996). Loads carried on the foot increase the physiological work rate more than loads carried on the torso. So, heavy shoes would cause a greater increase in physiological work rate than lightweight shoes. Softer-soled shoes reduce the physiological work rate compared to stiffer soled shoes. Oxygen Consumption As Jong as the work rate is not too high during constant-rate exercise, oxygen consumption will reach a steady-state. A secondary rise in oxygen consumption, or oxygen drift, may occur for extended periods of exercise (Poole and Richardson, 1997; Kearon et al., 1991). There appears to be both a fast and slow component to oxygen consumption during work. The fast component is responsible for the initial 42 steady-state reached. The oxygen drift is thought to be related to the slow co mponent. The slow component may also cause a greater than linear increase in the oxygen consumption with work rate above the anaerobic threshold. The presence of oxygen drift would be important to consider for a model of steady-state exercise. There are exercise levels for which oxygen consumption will continue to rise until the maximum oxygen consumption is reached, fatigue occurs, and exercises stops. While it may not be possible physiologically for a subject to attain the steady- state, the theoretical steady-state value is still necessary to determine the response (Givoni and Goldman, 1972). Slow Component of Oxygen Consumption Poole and Richardson (1997) stated that the four most important detenninants of oxygen consumption response during exercise were external work rate, work efficiency, whether the work was incremental or constant load, and the intensity level of the work (above or below the anaerobic threshold). The heavy exercise domain starts at the anaerobic threshold. The highest exercise level in this domain is the highest work rate at which blood lactate production can be stabilized, albeit at an elevated level (Poole and Richardson, 1997). The slow component of oxygen consumption is evident in this domain 80-100 seconds after the start of exercise (Poole and Richardson, 1997). Work efficiency is reduced in this domain. 43 The severe exercise intensity domain begins around 50% of the difference between the anaerobic threshold and Vo2max (Poole and Richardson, 1997). In this domain, blood lactate levels continue to increase and the slow component pushes the oxygen consumption towards Vo2max· Gaesser and Poole (1996) suggested that the increase in oxygen consumption for exercise above the anaerobic threshold (slow component) not be confused with oxygen drift. The authors suggested that oxygen drift occurs during prolonged moderate intensity exercise and is a small increase (200mL) in the oxygen consumption . The slow component of the oxygen consumption response on the other hand is only seen for exercise above the anaerobic threshold and is of much greater magnitude. It is the increase in oxygen consumption beyond the third minute of exercise (Gaesser and Poole, 1996). Whipp and Wasserman (1972) investigated the oxygen uptake kinetics for various intensities of constant-load work. They found that for low work rates, the oxygen consumption reached a steady-state within three minutes. At higher work rates, the steady-state was progressively delayed. A difference was found between the oxygen consumption measured at three minutes and that measured at six minutes. The authors found that this difference was a useful indicator of the slow component of oxygen consumption. Kearon et al. (1991) investigated oxygen consumption, minute ventilation, tidal volume, and respiratory rate during prolonged exercise at work rates of 34%, 43%, 63%, and 84% of maximal capacity in six healthy subjects. Subjects exercised 44 for 60 minutes or unti] they cou]d not continue. The average (± standard error of the mean) performance times at the four work rates were 60 ± 0 min, 56 ± 4.0 min, 37 ± 6 .6 min, and 12 ± 3.7 min, respectively. A regression line was fit to the average oxygen consumption data versus time for each of the work conditions. Data coJlected in the first four to six minutes was ignored as this was considered to be the time it took for the subjects to reach a steady state. A statistica11y significant increase in the oxygen consumption was declared if the slope of the regression line was significantly different from zero. At the lowest work rate, there was a sma11 but statistica1ly significant increase in the oxygen consumption from 1.47 to 1.52 Umin. Oxygen consumption increased during the 43% work rate from 1.76 to 1.93 Umin. the differences at these two work rates were in the 200 mL range that Gaesser and Poo]e (1996) suggested indicates oxygen drift rather than the s]ow component. For the third work rate, oxygen consumption increased from 2.35 Umin to 2.84 Umin. Finally, oxygen consumption values for the highest work rate increased from 3.13 to 3.59 Umin. AJl of the Increases were statisticalJy significant. Barstow and Mole (1991) investigated oxygen uptake kinetics during heavy exercise. Four trained cyclists completed four replications of cyc]e exercise at four Work rates, two of which were below the anaerobic threshold. The four work rates were 35, 55, 85, and 100% of maximal oxygen consumption. Each test consisted of four minutes of pedaling at 33W fo]lowed by eight minutes at the se]ected work rate 45 and then ten minutes of recovery at 33W. Two exponential models were fit to the data: ~Vo, (t) = AJ1-e-(r-TD)/r, ]+ Ai[l- e-(,-TD)/r2] ~ V 02 (t) = AJl -e -(r-TD,)/ri ]+ Ai[l - e- (1-TD2)/r2] (21) (22) where: ~ V 02(t), oxygen consumption response above baseline, Umin t, time starting from the onset of exercise, sec A 1, first steady-state oxygen consumption, Umin A2, second steady-state oxygen consumption, Umin TD1, TD2, time delays for phase two and three, respectively, sec -r1, -r2, time constants for phase two and three, respectively, sec The difference between the two equations was that the second equation was a more general form that allowed a second independent time delay. A single-exponential function of the form: ~ V Oz (t) = Aj- e-(1-TD)/ri] where: A3, the sum of A1 and A2 from the first equation T3 equals -r1 and T2 46 (23) fit the data for all eight exercise cases below the anaerobic threshold (two work rates for each of four subjects). So, for the oxygen consumption response below the anaerobic threshold, there is only one steady-state value, A3. For seven of the eight responses above the anaerobic threshold, a two- exponential function (equation 22) was found to fit the data. For the eighth case, the single exponential function (equation 23) was the best fit. The better fit of the two- exponential model indicated that for exercise above the anaerobic threshold there was a second component to the oxygen consumption that did not begin at the same time as the first exponential , but began later into the exercise. The authors concluded that this was evidence of a slow component of the oxygen consumption response. Equation 22 was modified in a later study (Mole and Hoffmann, 1999) to include baseline oxygen consumption in the response: A v· ( ) _ r,1 _ -(t-TD )/r, ]+ a fl _ e -(t-TD )/rs ] Ll Oz t - aR +aFv e sV where: aR, initial resting oxygen consumption, Umin aF, steady-state V 0 2 due to the fast component, Umin as, steady-state V 0 2 due to the slow component, Umin 'rF, time constant for the fast component, sec ~ time constant for the slow component, sec ~s, (24) Similar results were found by Paterson and Whipp (1991). Six healthy subjects perfonned two to four repetitions of cycle exercise from a baseline of 47 unloaded pedaling to one of two selected work rates, one at 90% of the anaerobic threshold and the other at the halfway point between the anaerobic threshold and V 02max, A single-exponential function was the best fit equation for the oxygen consumption response for the exercise below the anaerobic threshold. For exercise above the anaerobic threshold, the authors found that a two-exponential model, with separate time constants and time delays was the most accurate model. It was concluded that the slow component of the oxygen consumption response was a delayed-onset process. The two-exponential model has been shown to be accurate for predicting the steady-state oxygen consumption for exercise intensities above the anaerobic threshold (Bernard, et al., 1998). The two exponential response of oxygen consumption with time has been shown also in untrained subjects (Camus, et al., 1988). The physiological reason or reasons for the slow component of oxygen consumption are still under debate. Possible reasons include lactate, epinephrine, cardiac and ventilatory work, temperature, potassium, and recruitment of lower- efficiency fast-twitch muscle fibers (Gaesser and Poole, 1996). Poole et al. (1992) showed that most (86%) of the increase in oxygen consumption beyond the third minute was due to a increase in leg oxygen consumption. So, Gaesser and Poole (1996) suggested that factors that do not involve working muscles probably make only small contributions to the slow component. They suggested that muscle temperature and more importantly, the recruitment of lower efficiency fast-twitch muscle fibers were the major factors contributing to the slow component. 48 Steady-State Oxygen Consumption Equations that related physio1ogica1 work rate to RQ, NPRQ, or RER and oxygen consumption have been discussed previously. If the physiological work rate were caJculated using a separate method, the above equations could be solved for oxygen consumption in tenns of physiological work rate and RQ, NPRQ, or RER. Johnson (1992) fit equations to experimental data in Hurley et al. (1984) that related respiratory exchange ratio to percent of maximum oxygen consumption for trained and untrained subjects: RER = 0.842 V Os 02 s 0.1 untrained (25) V02max RER =0.778 Os V02 s 0.1 trained (26) V02max RER=0.826+0.160( V0 2 ) V02max V 0.1 s 02 s 0.8 untrained (27) V02max RER = 0.756 + 0.220( V0 2 ) V02max V O. ls 02 s 0.9 trained (28) Vo2max RER = -0.230 + 1.480( V0 2 ) Vo2max V 0.8 < 0 2 untrained (29) Vo2max V 0.9 s 02 trained (30) Vo2max where: RER, respiratory exchange ratio, dimensionless 49 V 0 2, oxygen consumption, Umin V 0 2max, maximum oxygen consumption, Umin These equations assumed RER=l.25 for untrained and RER=l.15 for trained individuals. Johnson 's (1992) RER equations could be substituted for NPRQ in the physiological work rate equation that could then be solved for oxygen consumption. For ve~ heavy exercise, errors in calculating the oxygen consumption and subsequent parameters would result when substituting RQ for RER. These errors should be evaluated. Other methods of determining oxygen consumption from work have been developed. Astrand and Rodahl (1970) showed in their Figure 13-2 that oxygen consumption was related linearly to physiological work rate. ACSM (2000) provided equations for estimating oxygen consumption for treadmill walking or running, ergometry, and stepping. Van der Walt and Wyndham (1973) developed equations to predict oxygen consumption for level treadmill walking and running. Their equations were of the form: where: Ai , A2, and A3, empirically derived regression coefficients m, mass, kg v, velocity, mis 50 (31) The authors did not investigate the effects of loads earned, grade, or of ambulating on surfaces other than a treadmill. Equations such as those developed by ACSM (2000) and Van der Walt and Wyndham (1973) are useful for predicting oxygen consumption of specific activities, but have no use in predicting the oxygen consumption of other activities such as painting or wood working. The Astrand and Rodahl (1970) plot may show an idealized relationship, but is worth considering. Astrand and Rodahl (1970) showed that the absolute oxygen consumption required by the body depended on the physiological work rate (their Figure 13-2). Logically, the higher the work rate, the greater the amount of oxygen consumed. Because their graph showed a completely straight line with no regression equation, the graph may show an idealized relationship. Effects of Age and Training The following factors may cause the actual oxygen consumption to differ from the predicted: faulty ergometer calculation, obesity, cardiovascular disease, pulmonary disease, fitness, exercise protocol, handrail holding, stride length, training specificity, habituation, and coordination (Robergs and Roberts, 1997; Wasserman et al., 1999). For trained individuals, steady-state oxygen consumption is lower at a given work rate than for untrained individuals due to an attenuation of the slow component (Gaesser and Poole, 1996). The reason for the decrease in the y 0 2 slow component may be due to the increase in mitochondria in all fibers that occurs with 51 endurance training. Training also can speed up the transient response while detraining and cardiopulmonary disease can decrease the response (Poole and Richardson ' 1997). Children have a greater gain for the fast component than adults and exhibit little or no slow component (Barstow, 1994). Anaerobic Threshold The point at which the lactate levels in the blood begin to rise during incremental exercise has been termed the anaerobic threshold (AT) (Wasserman ' 1973). When the oxygen required by the muscles can be supplied by ventilation alone, metabolism occurs aerobically. If the oxygen demand of the exercising muscles cannot be supplied by ventilation alone, then ATP production does not occur at the mitochondrial level (Claiborne, 1984) but is instead produced anaerobically (Sady, et al., 1980). Thus, around the anaerobic threshold, non-oxidative metabolism plays more of a role in energy production (Sady et al., 1980). Lactic acid production increases and is buffered by the bicarbonate system (Weltman and Katch, 1979), resulting in an increase in the production of non-metabolic carbon dioxide. The increase in CO2 production acts as an strong ventilatory stimulus (Sady et al., 1980), causing the minute ventilation-oxygen consumption relationship to increase beyond linear (Wasserman, 1973). There are invasive and non-invasive techniques for determining the anaerobic threshold. Wasserman et al. (1973) stated that the AT was the point of: "l) nonlinear 52 increase in minute ventilation, 2) nonlinear increase in carbon dioxide production, 3) an increase in end-tidal oxygen without a corresponding decrease in end-tidal carbon dioxide, and 4) and increase in the respiratory exchange ratio, as work rate was increased during exercise." The term "lactate threshold" is sometimes used to describe the point at which lactic acid begins to accumulate in the blood (Johnson , 199 l ; Johnson et al., 1995). The point at which minute ventilation increases beyond linear is sometimes ca11ed the "ventilation threshold" (Johnson, et al., 1995; Mahon and Vaccaro, 1989). Other researchers disagreed with the description of anaerobic threshold provided in Wasserman et al. (1973). Skinner and McLe11an (1980) labeled the set of responses observed by Wasserman et al. (1973) as the "aerobic threshold". They contended that there were rea11y three phases to exercise, not two. The second breakaway point was described as the point at which lactic acid increased from 4 mmol/L, FEc02 decreased, and hyperventilation increased. This point occurred between 65-90% of V ozmax and was termed the "anaerobic threshold" (Skinner and McLe11an, 1980). There has been some disagreement about whether the AT as determined by blood analysis is the same as that determined from respiratory gas exchange. Powers et al (1984) compared the onset of AT measured by blood lactate and estimated by the point where ventilation increased non-linearly. They found that the two points did not always occur simultaneously and suggested that there may be limitations to estimating the AT using respiratory gas exchange. However, Ivy et al. (1980) found 53 that there were no significant differences between the two methods of estimating the AT. Davis et al. (1976) found a correlation coefficient of 0.95 between the two methods. One of the major problems with determining AT using respiratory gas exchange is the subjectivity involved (Davis et al., 1976). Computer programs that use objective methods of determining AT from respiratory gas exchange have been developed (Herbert et al., 1982; Orr, et al., 1980). This eliminates the problem resulting from researcher subjectivity in detecting the point at which the curve departs from linearity. A new method of detecting the AT from gas exchange variables was presented by Caprarola and Dotson (1985). They plotted FEco2 versus percent of maximal oxygen consumption and fit a quadratic equation to the data. The point at which the curve was a maximum was the anaerobic threshold. The authors found good agreement between this method and standard techniques. Johnson et al. (1995) investigated the effects of full-facepiece masks and half- masks on ventilation threshold and lactate threshold on fourteen subjects undergoing incremental bicycle exercise. These researchers found that mask condition did not affect either the lactate or ventilation thresholds. Many studies investigating the relationship between anaerobic threshold and oxygen consumption have been performed. Subjects of these studies have been male and female , trained and untrained. 54 We1tman et a]. (1978) reported that for thirty-three femaJe co11ege students, the AT occurred at an average of 50% of V 02max· These researchers paired 22 subjects according to their Vozmax va]ues. Paired members had similar Vozmax values but different AT values. The average Vo2max for the two groups (36.66± 7.62 and 38.36±6.28 for the Jow and high AT groups respectively) were not significantly different statistica1Iy. The AT vaJues were significantly different. The AT values for the 1ow and high AT groups were 16.23 ±4.57 Umin and 21.35±4.14 Umin, respectively. This corresponded to an AT% of 44% and 56% for the Jow and high AT groups respectively. So, even though the two groups had similar subjects, the AT (m1/kg/min) was quite different. Dwyer and Bybee (1983) reported that the AT occurred at an average of 70±7% of V ozmax for twenty female recreationa] runners and cyclists. Average Vozmax was 38.4±4. 7 m1/kg/min. They found a high correlation (r = 0.87) between AT (Umin) and V 02max (Umin). Fifteen trained fema]e cross-country skiers aged fifteen to twenty with an average Vozmax of 47.3±3.6 m1/kg/min were studied (Rusko et a1., 1980). The AT (40.9±3.3 ml/kg/min) occurred at 85.7±6.6% of V 02max· A correlation (r=0.6) was found between Vozmax (m1/kg/min) and AT (ml/kg/min). An insignificant correlation was found between AT expressed as a percent of V 02max (AT%) and V 02max (m1/kg/min). Eighteen overweight females were studied by Sady et a1. (1980). Subjects were sp1it into three groups for different exercise treatments. Pre-training Vo2max and 55 AT values are reported for each of these three groups separately. The V 02max values for the three groups (n=7, n=7, and n=4) were 2.23±0.07, 2.09±0.18, and 2.31±0.1 2 Umin while the AT values were 1.02±0.06, 0.97±0.04, and 1.28±0.08 Umin , respectively. These AT values corresponded to 46, 46, and 55% of V02max ' respectively. Thorland et aJ. ( 1980) studied ten trained female collegiate cross-country runners. The AT occurred at average of 80% of V 02max· The anaerobic threshold expressed in ml/kg/min was highly correlated with maximal oxygen consumption (r = 0.81). Weltman and Katch (1979) found that thirty-one ma]e subjects with an average Vo2max of 51.36±6.36 m]/kg/min had an AT of 59.5±7.70% of V02max· They found a high correlation (r=0.81) between Vo2max (Umin) and AT (Umin). Thirteen trained men were studied by Powers et aJ. (1984). The AT of these subjects occurred at an average of 56% of Vo2max· Balsam (1988) studied fourteen male colJege soccer players with an average Vo2max of 57.4±6.18 m1/kg/min. The average AT occurred at 70.5±5.99% of V 02max· Robbins et aJ. (1982) found that for healthy adu]t males with a mean V02max of 59.2 mJ/kg/min, the AT occurred at an average of 65.3% of V02max. For ma]e college students perfonning arm-cranking, leg cycling, and treadmill walk-running, the AT occurred at average values of 46.5, 63.8, and 58.6% of V02max, respectively (Davis et al., 1976). Jones (1984) found that the AT occurred at 50% ± 4.8% of the Vo2max for inactive, young, adult male smokers (average y 02max: 34 ml/kg/min). For males aged 24-35, Bradley (1982) 56 found that AT occurred at 58.6%±10.7% of Vo2max (average Vo2max was 45.7 ± 7.9 ml/kg/min). These studies show that the occurrence of the AT is highly variable even among subjects of the same gender and similar ages and training statuses. Skinner and McLellan ( 1980) reported that the anaerobic threshold occurs between 65 and 90% of V 02max· The studies discussed here have shown values outside this range. These studies have reported that the anaerobic threshold can occur between 29 and 95% of maximal oxygen consumption. The anaerobic threshold for trained athletes occurs at a higher percentage of V ozmax than for untrained subjects. While the AT can be elevated after training even if there is not an increase in V 02max (Claiborne, 1984 ), generally the higher the Voimax, the higher the AT. A significant relationship between the AT and V 02max was reported by Dwyer and Bybee (1983), Rusko et al. (1980), Thorland et al . (1980), and Weitman and Katch (1979). The other researchers did not report on this relationship. Only one paper reported regression of AT% on Vo2max (Rusko et al., 1980); no correlation was found. The anaerobic threshold is important because relationships below the anaerobic threshold differ from the relationships above the anaerobic threshold (Johnson, 1991). Martin and Weil (1979) found that for incremental exercise below the anaerobic threshold, the minute volume increased linearly while above the threshold it increased at a greater rate. And, the time to reach a steady-state in oxygen consumption is longer above the anaerobic threshold (Wasserman et al., 1973). 57 Wassennan et aJ. (1973) suggested that for patients with severe respiratory tmpainnent, an AT may not be present because these subjects might not be able to exercise at a high enough rate to elicit lactic acidosis. For subjects with cardiovascular impainnent, the anaerobic threshold wiJJ occur at lower values than for healthy subjects (Wassennan, et al., 1973). Minute Ventilation Minute ventilation is the amount of air exhaled in one minute. It is found as the product of respiration rate and tidal volume. At rest, the minute ventilation is around 5-6 Umin. During mild exercise, this can increase to 75 Umin while during maximal exercise values up to 160 Umin occur. For endurance athletes, the minute ventilation may increase to as much as 27 times the resting value (Robergs and Roberts, 1997). As Jong as exercise intensity is not too high, the minute ventilation wiJJ reach a steady state. Because minute ventilation is related to oxygen consumption, an increase in the oxygen consumption due to oxygen drift or the slow component would cause a concomitant increase in the minute ventilation. During exercise with a progressive work rate, below the anaerobic threshold, minute volume increases linearly with oxygen consumption. Above the anaerobic threshold, minute volume increases exponentiaJJy (Martin and Weil, 1979). For constant rate work below the anaerobic threshold, minute ventilation reaches a steady-state (Wasserman et al., 1980). For exercise above the anaerobic 58 threshold, the time to reach steady state is prolonged. For very heavy exercise, a steady state may not be reached before the subject has to cease exercise. When constant rate work below the anaerobic work begins from rest, there is an initial abrupt rise in minute ventilation (Whipp et al., 1982; Johnson, 1991). The abrupt rise is thought to be neurogenic in nature (Johnson, 1991; McArdle et al., 1996). There may be a short duration plateau (20 seconds) immediately after the abrupt rise. Minute ventilation then increases exponentially to a steady state if the exercise is not too intense (McArdle et al., 1996). The steady state value attained depends on the intensity of exercise. If the work rate is very high, a steady state will not be achieved and the minute ventilation will increase progressively until the person ceases exercise (Wasserman et al., 1980). There is a large variability in the response of minute ventilation, and other respiratory parameters, to exercise. In fact, Johnson (1991) states that "respiratory responses are difficult to reproduce" and recommends that applications to individuals be made with caution. The variability of the minute ventilation response is less when related to carbon dioxide production instead of oxygen consumption (Wassennan et al., 1980). This indicated the importance of carbon dioxide in the control of respiration (Johnson, 1991). At low levels of exercise, increases in minute ventilation are brought about mainly by an increase in tidal volume, while at higher intensity levels, minute ventilation increases as a result of increased respiration rate (Johnson, 1991; McArdle et al., 1996). 59 Factors That Affect Minute Ventilation Age, training, and gender affect minute ventilation. Maxima] minute ventilation decreases with age. Additiona11y, for a given submaxima1 oxygen consumption (e.g., 2 Lpm), older subjects wi11 have a higher minute ventilation than younger subjects (Robergs and Roberts, 1997). Training results in a higher maxima] minute ventilation during maxima] exercise. During submaxima1 exercise, there is a reduction in the minute ventilation at a particular oxygen uptake after training. This indicates a lower oxygen cost of exercise for breathing (McArdle et al., 1996). Because minute venti1ation is related to body mass, male subjects genera1Iy have higher minute ventilations than female subjects (Johnson, 1991). 60 Tidal Volume Tidal volume is the amount of air exhaled with each breath. While some authors (McArdle et al., 1996; Robergs and Roberts, 1997) define tidal volume as the volume of air either inhaled or exhaled, these two volumes are not the same. The difference results mainly from the different temperatures of the inhaled and exhaled air. The different water vapor addfrion and different gas composition are smaller factors (Johnson, 1991). Tidal volume varies with age, gender, and size (McArdle et al., 1996). Males generally have larger tidal volumes than females. An average resting tidal volume for men is 600 mL while that for a woman is 500 mL. During exercise, tidal volume can reach values of 2 - 3 L. Tidal volume can be quite variable even when the subject is at steady state (Johnson, 1991). The interbreath variation is caused predominantly through changes in the inspiratory time. During exercise, tidal volume is increased by using parts of the inspiratory and expiratory reserve volumes. These volumes are the amount of air present in the lungs after a normal inhalation or exhalation. At low intensity exercise, the tidal volume increases causing an increase in the minute ventilation. Once the tidal volume reaches 50 _ 60% of the vital capacity, the minute ventilation is further increased through an increase in the respiratory rate (Wasserman et al., 1999). Vital capacity is the sum of the inspiratory reserve volume, expiratory reserve volume, and tidal volume. Maximum tidal volume has been reported to range from 45 _ 58% of vital capacity (Wasserman et al., 1999). 61 For constant rate exercise below the anaerobic threshold, the tidal volume is relatively constant with time. For exercise above the anaerobic threshold, the tidal volume may decrease slightly with time (Wasserman et al., 1980). Exhalation and Inhalation Times The prediction of inhalation and exhalation times can be accomplished using different approaches. Caretti et al. (1992) investigated the effects of exercise modality on breathing patterns. Subjects exercised on a bicycle ergometer and a treadmill. Other investigators have average consecutive breaths with different breathing frequencies and then evaluated the inhalation and exhalation times. Caretti et al. (1992) examined individual breathing frequencies and inhalation and exhalation times. Their rationale was that when consecutive breaths were averaged, the variability in breathing patterns and timing differences related to breathing frequency was masked. Individual breathing frequencies were grouped together into bins to aid in the analysis. The authors plotted inhalation and exhalation time versus breathing frequency. A regression curve was not fitted to the data, but a the relationship was observed to be similar to a power-law relationship. This relationship was qualitatively similar for both treadmiIJ and bike exercise except for respiration rates below 12 breaths/min. Below 12 breaths/min, the investigators found that exhalation time was significantly longer for treadmill exercise compared to bike exercise. A large variability in 62 inhalation and exhalation times was observed for breathing frequencies below 18 breaths/min. Above 18 breaths/min, the variability decreased. So, Caretti and Whitley (1998) showed that inhalation and exhalation times could be predicted from respiratory rate. Johnson and Masaitis (1976) took a different approach. By minimizing total respiratory work during a complete respiratory cycle, Johnson and Masaitis (1976) derived an equation to predict the ratio of inhalation time to exhalation time: r 3 -(~}-(J:!:!l.J = 0 1+µ I+µ (32) where: a) T=(::J (33) where -r = inhalation time/exhalation time ratio, dimensionless ti = inhalation time, seconds te = exhalation time, seconds b) A=(:,•:] (34) where ).. = ratio of first inhalation and exhalation Rohrer coefficients, dimensionless Kli = first Rohrer coefficient for inhalation, (cm 63 K1e = first Rohrer coefficient for exhalation ' (cm H20·sec)/L (35) where TJ = ratio of first inhalation and exhalation Rohrer coefficients, dimensionless K2i = second Rohrer coefficient for inhalation ' ( cm H20·sec )IL K2e = second Rohrer coefficient for exhalation ' (cm H20·sec)/L (36) where µ=dimensionless ratio VT= tidal volume, L The Johnson and Masaitis (1976) mode) assumes: "I) inhalation/exhalation times are determined by respiratory work during one cycJe; 2) expiratory work is important in determining inhalation/exhalation times; 3) energy stored during inhalation due to respiratory system compliance or inertance is fulJy recovered during exhalation." Equation 32 is a cubic equation and can be solved using a method such as Cardan 's solution (Korn and Korn, 1961). Inhalation and exhalation times were determined using an iterative process. The authors showed that the model had good qualitative and quantitative agreement between ca1cu1ated and experimental results. 64 Effect of lnspiratory and Expiratory Loading Resistance loading of the respiratory system causes changes in the respiration rate and in the duration of inhalation and exhalation. Inspiratory loading leads to an increased inhalation time and a decreased respiration rate. The subsequent exhalation is affected as well , with an increased exhalation time following an increased inhalation time (Cherniack and Altose, 1981). Expiratory loading leads to increased exhalation times and decreased respiration rates. These effects were shown by Caretti and Whitley (1998), Johnson et al. (1999) and Caretti et al. (2001 ). The effect of inspiratory resistance breathing on respiratory rate was investigated by Caretti and Whitley (1998). Subjects exercised on a treadmill at 80- 85% of V 0 2ma;,c while wearing a half-respirator with one of four inspiratory resistances ranging from 0.2 kP A to 0.49 kPa, measured at a steady airflow rate of 1.42 mis. Treadmill speed and grade were adjusted for each resistance condition so that the subject was at 80-85% of y 0 2m.a;,c · Respiratory rate decreased from the control condition 4.6%, 10.7%, 16%, and 32% for the four resistance conditions. The respiratory rate for R4 (highest resistance) was significantly different from the control , R 1, and R2 conditions. Johnson et al. (1999) investigated the effects of inspiratory resistance on work performance. Subjects exercised on a treadmilJ at constant speeds and grades that were chosen to elicit respiratory stress. A full -facepiece respirator was worn for each of six tests with different levels of inspiratory resistance. The inhalation resistances ranged from o. 78 to 7.64 cm H20-sec/L. The exhalation resistance for all tests was 65 l .3 cm H20·sec/L. It was found that minute volume decreased as inhalation resistance increased: V min = -.0687R + 1.325 (37) where: V min , minute volume, Lisee R, resistance, cm H20·sec/L Caretti et al. (2001) conducted a similar study investigating the effects of exhalation resistance on work perfonnance. Exhalation resistances ranged from 0.27 to 27.35 cm H20,sec/L. Average minute volumes decreased as expiratory resistance increased: V min = - 1.76R + 73.16 (38) So, in both cases (Johnson et al., 1999; Caretti et al., 2001), as resistance increased, minute volume decreased. Caretti and Whitley (1998) found that tidal volume did not change with resistance for exercise at 80-85% of V 02max, So, assuming a constant tidal volume during steady state work, a decrease in the minute volume would lead to a decreased respiratory rate. 66 Oxygen Deficit Because the oxygen consumption does not rise immediately to the steady state value, there is a difference between the oxygen required by the body (the steady state value) and the actual oxygen consumption (that during the exponential increase). This difference is termed the oxygen deficit. The oxygen deficit is found as the product of steady-state oxygen consumption and the time constant of the exponential rise (Whipp et al., 1982). During the deficit, mitochondrial respiration is supplemented through energy generated by creatine phosphate and glycolysis (Robergs and Roberts, 1997). The increase in oxygen consumption due to the slow component means that the oxygen deficit as a percentage of the total oxygen required increases as the work load increases above the anaerobic threshold (Whipp and W assermnan, 1972). Whenever there is a difference between the actual and required oxygen consumption, there is a deficit. As a trained person will reach steady state faster than an untrained individual, the trained person incurs less of an oxygen deficit. Performing a warm-up can also decrease the oxygen deficit (Robergs and Roberts, 1997). When a steady-state can be reached, the oxygen deficit is the difference between steady state and non-steady state oxygen consumption. However, a deficit may occur also when a respirator is worn. Respirators have been shown to cause hypoventilation (Johnson et al., 1999; Caretti et al., 200l), so a respirator wearer has 67 a lower minute ventilation and thus a lower oxygen consumption than that required by the body. The greater the deficit, the shorter the performance time. Respiratory Work Rate "It has long been assumed that respiration is physiologically adjusted to yield optimum respiration ratio, ratio of inhalation time to exhalation time, expiratory reserve volume, dead volume, airways resistance, and airflow waveshape (Johnson ' 1993)." These adjustments are especially important during exercise when there is a competition among the skeletal, cardiac, and respiratory muscles for the limited oxygen available. Because of the limited oxygen supply and the fact that respiratory work does not contribute to the activity being performed, it is logical that respiratory work should be minimized during exercise. Data taken during exercise support this contention (Johnson, 1993). At rest, respiratory work accounts for 1-2% of the total oxygen consumption (Johnson, 1991). This increases up to 10% during exercise. Changes in airlJow waveshape could have a significant effect in a model of respiratory work. Indeed, Yamashiro and Grodins (1971) found a 23% lower work rate for a rectangular waveshape compared with a sinusoidal waveshape. They used a simple model that had only had one resistance and one constant compliance. Respiration occurs with different flow patterns that depend on exercise intensity. At rest, inhalation has a sinusoidal waveshape while exhalation occurs with an exponential waveshape. Both inhalation and exhalation waveforms are trapezoidal 68 with rounded comers during moderate exercise. Inhalation waveforms remain trapezoidal during heavy exercise, but exhalation waveforms return to an exponential shape. At rest, both inhalation and exhalation waveshapes appear to be unrelated to work rate. Yamashiro and Grodins (1971) found that the sinusoid resulted from a mean squared acceleration criterion. They reasoned that the sinusoidal waveshape resulted in improved gas transport efficiency and a uniform ventilation of the lungs. The resting exponential exhalation waveshape is due to passive exhalation. There is little muscle activity required during exhalation at rest. The energy comes instead from elastic energy stored in the chest wall, which is expanded during inhalation. Additional energy comes from air that is compressed in the lungs during inhalation. During moderate exercise, both inhalation and exhalation are active. The trapezoidal waveshapes appear to be related to respiratory work rate, although they differ from the rectangular waveshape that minimizes respiratory work (Yamashiro and Grodins, 1971 ; Johnson and Masaitis, 1976). Both Hamalainen and Sipila ( 1984) and Ruttiman and Yamamoto (1972) gave possible reasons for the trapezoidal shape. Hamalainen and Sipila (1984) got a trapezoidal waveform when they included an additional term in their optimization criteria that is equal to the square of muscular pressure times the volumetric flow rate. This term accounts for the decreased muscular efficiency seen at higher loads. Ruttimann and Yamamoto (1972) also obtained a trapezoidal waveform, although the slope was in the opposite direction. Their waveform resulted when they minimized respiratory work while using an 69 airways resistance that increased as volume decreased. Johnson (1986) found that a part of lower airways resistance has this inverse effect. The reason for the rounded comers may be that rapid accelerations are penalized to avoid damage or loss of control (Johnson, 1991 ; Johnson, 1993). Or, the rounded corners may indicate that the strength of the respiratory muscles is limited (Johnson, 1993). The same inhalation optimization criteria during moderate exercise is in effect during heavy exercise (Johnson, 1991). Thus, the waveshape remains trapezoidal. The exhalation waveshape returns to exponential although the reason for the exponential waveform differs from that at rest. During heavy exercise, exhalation flow rate is limited. Johnson and Milano (1987) plotted transpulmonary pressure against expiratory flow rate along lines of equal lung volume. They found that a point was reached beyond which the flow could not be increased. The limiting flow rate was inversely related to the Jung volume. The very abrupt transition to the exponential waveform only occurs during a maximal effort when the respiratory system is extremely taxed (Johnson and Milano, 1987; Johnson, 1993). Because flow rates and respiratory muscle pressure were so high, much more energy was required by the exponential waveform (Johnson, 1993). There is one other characteristic of the moderate and heavy exercise waveforms that needs to be discussed. There are dimples that often appear in the waveforms. The reason for these dimple is not clear (Johnson, 1991). However, when minimizing the Hamalainen and Viljanen (1978) inhalation optimization criteria, the dimples appear in the wavefonn under certain conditions (Johnson, 1991). 70 Respiratory Work Rate Model The work rate of breathing with different waveshapes was investigated by Johnson (1993). The model of the respiratory airways that was used contained a small number of elements with nonlinearities resulting from the airways and mask (Johnson, 1992). The model used the modified Rohrer equation: • • • KV V-V •• p= K1 V+ K? V 2+-3 -+ r + IV ~ V C (39) where p = respiratory muscle pressure, N/m2 • 2 V = respiratory flow rate, m /sec V = lung volume, m 3 •• 3 2 V = volume acceleration, m !sec Vr = resting volume of the lung, m3 K 1 = first Rohrer coefficient for the respiratory system, N=:sec/m5 K2 = second Rohrer coefficient, N::::sec2/m8 K3 = "third" Rohrer coefficient, N:::sec/m2 C = respiratory compliance, m5/N 21 5 I= respiratory inertance, N:::sec m This model was sufficient for both inhalation and exhalation if different values were used for the parameters Kr to K3, C, and I (Johnson, 1992). An extra term must be added when flow rate nears maximum exhalation flow rate (Johnson, 1993): 71 • • KV V-V .. K p ~ = K1 V + K 2 V 2 + _3 - + r +IV+ 4 V C (i-J] where Pe = respiratory muscle pressure at airflow limitation, N/m2 Ki = additional coefficient, N/m2 V L = limiting flow rate, m3/sec (40) Waveshapes . Johnson (1993) developed the equations for the respiratory Work rates when breathing with a sinusoidal, rectangular, truncated exponential, hybrid exponential, and trapezoidal breathing pattern. Linear, quadratic, volume dependent, compliant, and inertial pressure terms were included. Variable Lung Volume. The expiratory reserve volume changes during exercise thus changing the initial lung volume. The correct lung volume needs to be included in the volume dependent and compliant work rate terms. For the volume dependent tenn, the correct volume is simply inserted into the formula. For the compliant tenn, it was not necessary to change the equation as Jong as exhalation was active and the whole breathing cycle was considered. This was because the added tenn would be the same magnitude but opposite sign for inhalation and exhalation, thus canceling its effect. 72 Maximum Expiratory Flow. Expiratory flow rate can become limited durino b maximal exertion. This limitation can cause respiratory distress and early termination of exercise for people wearing respirators (Johnson and Berlin, 1974). A term for maximum respiratory rate of work must be added to the limited flow hybrid exponential work rate equations (Johnson, 1993): T • 1 J . W R(6) = - Pmax Vldt To . where WR ( 6), average respiratory work rate during flow limitation N·m/sec T, duration of wavefonn, sec t, time, sec (41) ' Effect of Waveshape on Respiratory Work Rate. The work rate while breathing with each of the five waveshapes was investigated during rest and light, moderate, heavy, and very heavy exercise. The lowest work rates occurred with the rectangular wavefonn. Comparisons were made to the rectangular waveform. The increased cost of the sinusoid for inspiration ranged from 9% at light exercise to 16% at very heavy exercise. The inspiratory trapezoid had an increased cost of 3% at light exercise and 7% during heavy exercise. The truncated exponential costs 30% more at light exercise and 9% during heavy exercise for inspiration. Finally, the hybrid exponential for inspiration was 29% higher for light exercise and 12% higher during 73 very heavy exercise. For exhalation, the work rates were lower than for inhalation because of longer inhalation times. Wavefonn Transition Little work has been done on the transition between waveshapes during exercise. This is important, because as shown in Johnson (1993), the work rate is dependent on the breathing wavefonn. Hamalainen and Vi1janen (1978) developed a model of the control of the breathing pattern during respiration based on optimization criteria. The performance criteria were chosen to minimize the oxygen cost of breathing. Both criteria have an average square of volume acceleration tenn. The inspiratory criterion is the weighted sum of that term and the mechanical work perfonned by the inspiratory muscles. The expiratory criterion includes an integral square driving pressure in place of the mechanical work tenn. For inhalation, the authors found that when the ratio of pressure times flow to the square of volume acceleration became large, a transition occurred from a sinusoidal to a trapezoidal wavefonn. Similarly for exhalation, when the ratio of pressure squared to volume acceleration squared became large, the waveshape changed from exponential to trapezoidal. Their method is not practical for this model because the weighting functions, a, and a2, are specific to the individual being tested and have no known physiological basis. The authors noted that different alpha parameters made sense 74 because "the airflow patterns of any given individual look as unique as fingerprints (Hamalainen and Viljanen, 1978)." But, this means that each person must be tested and the actual breathing waveforms compared to the predicted waveforms. The Weighting functions are adjusted until the differences between the two sets of waveforms are minimal. A better means is necessary to determine when transitions in the respiratory wavefonns occur. 75 Respiratory Protective Masks Respiratory protective devices have a profound impact on the wearer. Vision communications, and personal support (wiping of nose, drinking) are all hindered. Problems occur due to sweat accumulation inside the mask and reduced heat loss through the mask. Sore neck muscles and skin initation become a concern with extended wear. The physical characteristics of the respirator, the inspiratory and expiratory resistance, the dead volume, and the weight, affect the physiological response and impede performance. The influence of each of these factors depends in Part on the work intensity and the type of task. Other important factors to consider are variability, anxiety, and hypoventilation. Physical Characteristics Resistance. A person wearing a mask must overcome the resistance to breathing caused by the filter and the inspiratory and expiratory valves in the mask. A number of studies have investigated the effects of external resistance on pulmonary function. Flook and Kelman (1973) investigated the effects of increased inhalation resistance on seven subjects exercising on a bicycle ergometer for ten minutes at 35, 50, and 70% of y 02ma.JC· The inhalation resistances were 8.9, 16.5, and 53.1 cmH20!IJs measured at a steady flow of 1 Us. These resistances were chosen to represent resistances seen in patients with pulmonary disease. Regression equations 76 , fit to their data showed that minute ventilation decreased with increased resistan ce. The slope coefficients for these equations for work done at 35 50 and 7om0 v ' ' ,c 02max were -0.0023 , -0.005, and -0.0214, respectively. Regression equations fit to the tidal volume data indicated that at 35%Vo2max, the tidal volume increased with increased resistance while tidal volume was virtually unaffected by resistance at the other two work rates (r = 0.05 and r = 0.005). The slopes of these equations in order of increasing work rates were 0.0078, 0.0011, and 0.0009, respectively. The effects of three inhalation resistances on subjects performing steady-state bicycle exercise was investigated by Demedts and Anthonisen (1973). Exercise periods lasted five minutes if possible or three minutes when the work load could not be tolerated for the fu]] five minutes. The work loads were 82, 131, 196,245, and 270 W. The resistances read off a pressure-flow graph at approximately 1.4 Us were 1.6, 3.1, and 12.4 cmH20/LJs. The dead space for a11 conditions was 350 mL. The authors found that minute ventilation was not decreased by the lowest resistance. A statistica11y significant 12% decrease occurred for the middle resistance at the highest work Joad while the highest resistance caused a 50% decrease at the higher work rates. Silverman et al. (1951) investigated the effects of two combinations of inhalation and exhalation resistance on 18 healthy males during bicycle exercise at constant rates of O, 34, 68, 102, 136, 181,226, and 271 W. Not a]] subjects completed a]] conditions. Data were recorded at six, eight, and ten minutes into the exercise. The inhalation and exhalation resistances were 0.4 and 0.2 cmH20!IJs for the ]ow condition , and 4.5 and 2.9 cmH20/LJs for the high condition. A third 77 condition was tested at the 68 W work rate only. The inhalation and exhalation resistances for this condition were 4.5 and 1.9 cmH20/Us. The authors found that the minute ventilation was reduced almost 20% at the highest two work rates. The authors stated that the resistance used did not affect tidal volume at work rates below 181 W. The percent change in the minute ventilation, respiratory rate, and tidal volume from the low to high resistance conditions was detennined at each work rate. Tidal volume was determined by dividing the mean minute ventilation by the mean respiratory rate. The results are shown in Table 2. Table 2. Percent changes in minute ventilation, respiratory rate, and tidal volume fr th 1 h' h · d"tions DataarefromSi1vennan t 1 (1951) om e ow to 1g1 resistance con 1 e a. VE (Us) RR (bis) VT(L) % change % change % change Rest -13.2 1.4 -14.7 0 -7.6 -12.0 4.0 34 -5.1 -13.4 7.3 68 -10.7 -9.7 -1.0 102 -3.0 -2.2 -0.8 136 -11.9 -10.9 -0.8 181 -16.9 -7.1 -9.2 226 -27.9 -19.0 -7.5 271 -26.0 -13.3 -11.2 It can be seen from the table that tidal volume was affected at low work rates. In fact, the tidal volume increased at the two lowest work rates. At work rates of 68, 102, and 136 w, the tidal volume does not appear to be affected by the resistances used. At work rates above 181 W, the tidal volume decreased with added resistance. Cerretelli et al. (1969) assessed the effects of two resistances on two subjects during treadmill exercise at work rates ranging from about 70 to about 210 cal/kg 78 min. Subjects inhaled and exhaled against the same two resistances of 8.5 and 16_9 cmH20/Us. The minute ventilation for the two subjects decreased at all work rates as the resistance increased. Hermansen et al. (1972) investigated the effects of a respirator mask and breathing valve on minute ventilation and tidal volume on ten healthy subjects performing on a bicycle ergometer at work rates of 49, 98, 147, and 196 W. The inhalation and exhalation resistances of the mask were 9 and 2.6 crnH20/Us, respectively while those of the valve were 1.7 and 1.7 crnH20/Us. Minute ventilation was always lower with the mask than with the valve. At the highest work load, the decrease in minute ventilation was 43%. Tidal volume was greater with the mask up to a minute ventilation of approximately 70 Umin. After that, tidal volume decreased with added resistance. The effect of inspiratory resistance on breathing parameters was investigated by Caretti and Whitley (1998). Subjects exercised on a treadmill at 80-85% of y 0 2max while wearing a half-respirator with one of four inspiratory resistances ranging from 0.2 kP A to 0.49 kPa, measured at a steady airflow rate of 1.42 mis. Treadmill speed and grade were adjusted for each resistance condition so that the subject was at 80- 85% of V 02max· Tidal volume was shown to be relatively constant across the respirator conditions. No significant differences among the conditions were found. The differences from the control condition were +1 %, 0%, +1.l %, and -2.7% for the Rl, R2, R3, and R4 conditions respectively. However, minute ventilation decreased as resistance increased. The differences were significant between the control and R4 79 conditions. The decreases in minute ventilation from the control condition were 2.4%, 9.8%, 14.9%, and 35.4% for the RI, R2, R3, and R4 conditions respectively. Johnson et al. (1999) quantified the effect of increased inhalation resistance on minute ventilation. Twelve subjects exercised at 80-85% V 02max until their volitional end-point while wearing a U.S. Army M-17 respirator with one of six different inhalation resistances. Plugs with different size holes bored through the center were placed in the inhalation ports to modify the resistance. The inhalation resistances were 0. 78, 1.64, 2.73, 3.32, 6.47, and 7.64 cm H20/I.Js at a flow of 1.42 Us (85 Umin). The exhalation resistance for all tests was 1.3 cm H20/I.Js. The relationship between minute volume and inhalation resistance was found to be: VE = -0.0687 · R inh + 1.325 (42) where: VE, minute volume, Us R. h inhalation resistance, cmH20/I.Js m, A similar study was conducted to examine the effect of increased exhalation resistance on work performance and ventilation (Caretti, et al., 2001). Subjects wore a U.S. Army M40 respirator with one of five exhalation resistances while exercising on a treadmill at 80-85% Vozmax· The exhalation resfatances were 0.47, 1.81, 4.43, 12.27, and 27.35 cm HzO/Us. The inhalation resistance for all conditions was 3.17 cm HzO/Us. Lower minute volumes were found for increasing exhalation resistance: VE = -Q.0299 · Rexh + 1.2365 (43) 80 where: VE, minute volume, Us Rexh, exhalation resistance, cmH20!Us So, in both cases (Johnson et al., 1999; Caretti et al., 2001), as resistance increased, minute volume decreased. The effects of the inhalation resistance were three times that of the exhalation resistance (Caretti et al., 2001). The above studies indicated that at all work rates, inhalation and exhalation resistance caused a decrease in minute ventilation. Only one study contradicted this. Demedts and Anthonison (1973) found that minute ventilation was not decreased at their lowest resistance. Flook and Kelman (1973), Hennansen et al. (1972), and data from Silverman et al. (I 95 I) indicated that at low work rates tidal volume was increased by resistance. Resistance at higher work rates has been reported to not have an effect on tidal volume (Flook and Kelman, 1973; Caretti and Whitley, 1998) or to decrease tidal volume (Silverman et al., 1951; Hennansen et al., 1972). In addition to increasing the inhalation and exhalation resistance, the valves also require an additional amount of pressure to open the valves. Cummings (1968) investigated the pressures required to open the valves in an MI 7 mask. The inspiratory pressure was found to be: • 0 7 2 P; = 3.227 xI05 V + 5.609xI0 V (44) where P1, inspiratory pressure inside the mask, N/m2 81 . V = flow rate, m3/sec The expiratory pressure for the same mask was (Cummings, 1968): Pt! = 59.93 + 6.629x104 V + 1.376x101 where Pe, expiratory pressure inside the mask, N/m2 V = flow rate, m3/sec (45) The constant term in the Pe equation is the pressure needed to open the val ve. This results in an addition to the respiratory work rate (Johnson, 1992): w (7) = 005 V. T(l + - O.BTIT) R • Po max e (46) • where W R(7), respiratory work rate due to constant pressure tenn, w 2 Po. constant term, Nim V max , maximum flow rate during breathing wavefonn, m3 /sec T, waveform duration, sec T, respiratory time constant, sec Dead Volume. Dead volume, or dead space, is the amount of air present that does not take place in respiration, including air in the nasal passages and throat. This volume is increased when an object, such as a snorkel, mask, or breathing tube, is 82 placed over the mouth and/or nose. Carbon dioxide accumulates in the dead vol ume, causing it to act as a respiratory stimulant. As airflow increases, so does dead volume. This occurs because when the flow rate increases, the airflow becomes more turbulent, causing a greater mixing of gases. Thus, air that was trapped at corners and around objects becomes mixed with the airflow, increasing the dead volume. The volumetric space inside a respirator is tenned the nominal dead volume while dead space as a function of tidal volume is tenned effective dead volume. Breathing through an external dead volume causes a performance decrement. Johnson, et al. (2000) investigated this effect by having subjects walk on a treadmiJJ at 80-85% V02max with respirator configurations giving a range of dead volumes. While performance time was affected, no effect of dead volume on minute ventilation, tidal volume, or oxygen consumption at termination was found. Stannard and Russ (1948) studied the effects of increasing dead volume on minute ventilation and tidal volume for seven subjects at rest and during light exercise. The light exercise was chosen as the work rate at which the resting oxygen consumption doubled. No indication of Vo2max was given. Nominal dead spaces of 250, 350, 420, 450, and 540 mL were used. At rest, the tidal volume increased as dead volume increased. During light exercise, tidal volume increased with added dead volume, but the changes were smaJJer. For the lowest dead volume, the change in tidal volume was not significant. The minute ventilation increased with added dead volume for resting and lightly exercising subjects. The authors noted that the regression Jines fit to the data 83 had similar slopes. The near constant difference between the two lines was reported to be approximately 2 Umin. In 1980, Ward and Whipp studied the effects of dead volume on minute venti lation of three subjects. The authors concluded that minute ventilation increased during rest and moderate exercise as a result of added dead space. The three studies noted above only looked at rest, light exercise, and heavy exercise. Harber and colleagues have completed a number of studies in which they investigated the effects of inhalation resistance and dead volume on breathing parameters at rest and during moderate exercise. Unfortunately, most of their infonnation can not be used in a model. In one study (Shimozaki et al., 1988) only subjective responses were reported. In another study (Harber et al., 1982) subjects were allowed to pick their own work rate so that it was consistent with 1ong-tenn work. Finally, three studies (Harber et al., 1984; Harber et al., 1988; Harber et al., 1990) were conducted in which one load, a combination of inhalation resistance and dead volume, was applied. The effects of the resistance and dead volume on the breathing parameters could not be separated. Mass and Load Placement. The mass of the mask will increase the external work rate. The equation developed by Pandolf et al. (1977) and the external work rate equation presented by Aoyagi et al. (1995) included total mass (body mass plus load mass) in the calculations. If the external work is specified and not calculated, the external work rate without the mask will be increased. The increase will equal the percentage increase in mass represented by the mask. Thus, a typical mask has a 84 mass equal to 1.4% of the nonnal body mass of a man. The work rate for that mask would be increased by 1.4% to account for the added mass of the mask. The respirator mass is not distributed evenly over the head. An eccentricity factor takes into account this fact. Other Factors Variability. The variability in response to respirators wear across the population underscores the necessity of using large sample sizes in conducting studies and in calibrating and validating models. The study by Johnson et al. (1999) showed that three of the twelve subjects were not sensitive to inspiratory resistance and indeed showed little perfonnance decrement. A study examining the effects of exhalation resistance (Johnson, et al., 1997) found that three of ten subjects could perform no treadmill work when the resistance was very high, but that the other seven were able to perfonn for two to ten minutes. Finally, the performance of subjects who scored an anxious rating on the Spielberger State-Trait Anxiety Test was dependent on the numerical score, while those classified as non-anxious had performances unrelated to their score. Anxiety. Psychological factors can play a large role in whether or not a person can tolerate respirator wear. To detennine the amount of influence such factors have, Johnson, et al. (1995) conducted a exercise study in which subjects took the Spielberger State-Trait Anxiety Inventory (STAI) to assess their anxiety level. 85 Twenty subjects exercised at 80-85% of their age-predicted maximum heart rate until their volitional end-point. The performance times of subjects classified as non- anxious (ST AI scores less than 34) were unrelated to the STAI score. However, for anxious subjects, the performance rating was related to the anxiety score. Someone with a STAI score of 40 would suffer a 25% decrement in performance. A highly anxious person (STAI score of 70) would have a 79% decrement and would therefore only achieve a 21 % performance rating. Hypoventilation. Hypoventilation is a condition in which the subject is breathing at a lower minute volume than normal. This may be due to either more shallow breaths or less frequent breaths, or both. The hypoventilating person must extract more oxygen from each breath as the oxygen requirements of the body are unaffected by the decreased minute volume. As less air is exhaled during hypoventilation, the carbon dioxide concentration in the exhaled air must increase. Thus, high concentrations of carbon dioxide and low concentrations of oxygen in the exhaled air indicate that a person is hypoventilating. Hypoventilation has been evident in two respirator studies. The first study (Johnson, et al., 1995) involved incremental bicycle exercise while wearing an Ml 7 respirator. Hypo ventilation was indicated by high Fscoz and low Fso2 values during respirator wear. Subjects participating in a study on the effects of inspiratory resistance on performance time also evidenced hypoventilation (Johnson et al., 1999). Subjects had decreasing minute volumes and oxygen consumption as resistance increased. 86 OBJECTIVES The objectives of this research were to: 1. Develop the structure for a mode] of the effects of respiratory protective masks on humans during physical activity; 2. Develop equations for the model structure; and 3. Combine the model equations into a tool to aid respirator designers by implementing the model in a high-level programming language. 87 EQUIPMENT Experimental Testing Experimental testing was conducted in the Human Petformance Laboratory at the University of Maryland College Park. The testing system consisted of a treadmill , gas collection system, respiratory protective mask, and heart rate monitor. Treadmill Subjects exercised on a Quinton Q65 treadmill (Quinton Instrument Co., Bothell, WA) with allowable speeds of 0.58 mis to 7.83 mis (1.3 mph - 17.5 mph) and grades of O to 25%. Three subjects used a 22.5 cm high step-stool (Brewer Quality Health Care Equipment, Menomonee Falls, WI) for the lowest work rate. Gas Collection System Expired air from the subjects passed through a breathing tube (Warren E. Collins, Braintree, MA) into a 3L mixing chamber and then through a heated Fleisch Number 3 pneumotach (OEM Medical, Richmond, VA). Inhaled air passed through the heated pneumotach into separate tubing connected to the inhalation side of the respirator. Exhaled oxygen and carbon dioxide concentrations were sampled from the mixing chamber by a Perkin-Elmer (Pomona, CA) MGA 1100 mass spectrometer. 88 The pneumotach was connected to a Validyne DP-15 differential pressure transducer (Validyne, Northridge, CA) and Validyne CD-12 transducer indicator. The signal from the transducer indicator was split to two separate computers equipped with DAS-8 (Keithley Data Acquisition, Taunton, MA) data acquisition boards. The program PNEUMO (Johnson and Dooly, 1993) was run on one computer and was used to collect minute volume, tidal volume, respiratory rate, inhalation time ' and exhalation time. A second computer was used to run V02_2000, a program developed in the Human Petformance Laboratory that provided exhaled concentrations of carbon dioxide and oxygen, minute ventilation, tidal volume, and relative and absolute oxygen consumption. The output port on the mass spectrometer was connected to the DAS-8 board on the second computer. For the maximal oxygen consumption test and levels determination session, subjects used a Hans-Rudolph, Inc., (Kansas City, MO) 2700 series adult large one- way non-rebreathing valve and either a half-mask (Hans-Rudolph Mouth/Face Mask) with head harness (Hans-Rudolph Head Cap Assembly) or bite-block mouthpiece and nose-clip. Each subject used the same type of equipment (half-mask or mouthpiece) for both the maximal oxygen consumption test and the session during which treadmill speeds and grades were determined to elicit the target intensity levels. 89 Respiratory Protective Masks Subjects wore a U.S. Army M-40 full-facepiece respirator for each of the respirator conditions. The M-40 is a negative pressure, air-purifying respirator that has a molded rubber facepiece and an elastic headhamess. The right inhalation port was closed off. An adapter was screwed into the left inhalation port to allow plug resistances to be placed in the flow path. An 86 cm long, 3.5 diameter flexible tube with a PVC adapter was placed over the exhalation port of the mask. Plug resistances with hole diameters of 11mm and 8 mm were used on the inhalation side in addition to the standard inhalation valve in the respirator. Exhalation resistances were either the standard or step (non-standard) flap valves for the M-40 respirator. Three resistance combinations were used. Respirators A, B, and C had inhalation and exhalation resistances of 0.88 and 1.69, 1.84 and 1.69, and 5.73 and 1.01 cmH20/Us measured at a steady flow of 1.42 Us. The approximate nominal dead volume was 300 mL. Heart Rate Monitor Heart rate was monitored using a 3-lead electrocardiogram (ECG) (Component Monitoring System, Hewlett Packard, Palo Alto, CA). 90 Software In addition to standard word-processing and spreadsheet software, two software packages were used in this research. Statistical analyses were performed using SPSS/PC+ Studentware Plus (SPSS, Inc., Chicago, IL) statistical package. The model was programmed in Visual BASIC 6.0 (Microsoft Corporation, Redmond, WA) on a Pentium 133MHz computer. 91 PROCEDURE The development of the model occurred in four stages. The first stage involved establishing the structure of the model. In the second stage, experimental data were obtained for use in stage three. Equations were developed to fill the model structure during stage three. The fourth stage involved implementing the model in Visual BASIC and evaluating the results. Structure of the ModeJ The intent of the model was considered in developing the structure of the model. The desired outputs were selected first. Required inputs were then chosen. The steps needed to proceed from the inputs to the outputs were specified. A flow chart was developed. Experimental Testing Five male and three female subjects between the ages of 23 and 38 were recruited for the study. All subjects were either students at the University of Maryland College Park or had participated in prior testing in the Human Performance Laboratory. The protocol was approved by the University of Maryland Institutional Review Board (see Appendix A). 92 Prior to participating in the study, subjects filled out a detailed medical history questionnaire and PAR-Q to determine if there were any medical conditions or medications that would preclude their participation in the study. Prospective subjects completed the Speilberger Trait Anxiety Inventory (Speilberger, 1983). Prospective subjects who scored a 45 or higher were excluded due to the possibility that they would exhibit anxiety while wearing the respirator. Two subjects who scored just above 45 ( 46 and 48) were included as they had participated in prior respirator research studies without difficulty. All subjects received a verbal description of the study and signed an informed consent document prior to the start of testing. All testing procedures were conducted at ambient room temperature (22- 230C) in an environmentally controlled laboratory to minimize environmental influences on the data. Each subject was instructed to get adequate rest the night before each test, to eat breakfast or lunch, and to drink plenty of fluids , excluding alcohol and caffeine, before reporting to the laboratory. Prior to each test session, the subject was questioned to insure that no condition existed in the subject that would jeopardize his/her safety or health. Examples of such conditions would be an upper respiratory tract infection, excessive fatigue, or musculoskeletal injuries. Individuals who reported such conditions were rescheduled at another time after they had fully recovered from their ailment. Subjects were clothed in their own T-shirt, shorts, socks and sneakers for all exercise trials. At least two personnel certified in ' cardiopulmonary resuscitation were present for all testing. Prior to the start of the test trials, each subject completed a test to determine maximal oxygen consumption using an incremental treadmill exercise protocol. 93 Subjects wore either a mouthpiece and noseclip or a Hans Rudolph half-mask for the testing. The tests was terminated if any of the following conditions occurred: oxygen consumption changed by less than 200 ml/min with increasing workrate, respiratory exchange ratio exceeded 1.0, a maximal age-predicted heart rate was achieved, or a rating of perceived exertion (RPE) greater than 17 ( very hard) was given. Heart rate ' electrocardiogram, and RPE were monitored during V 02max testing. Subjects returned to the laboratory to determine the treadmill speed and grade required to elicit the following intensity levels: 25-30, 35-40, 45-50, 65-70, and 80- 85% of maximal oxygen consumption. For three subjects, oxygen consumption was greater than 25-30% at the lowest treadmill speed of 0.58 mis and 0% grade. The lowest work rate for these subjects was done on a 22.5 cm high step-stool instead of the treadmill. Heart rate, ECG, tidal volume, minute volume, oxygen consumption, and RPE were monitored during this session. Three conditions of submaximal exercise testing were randomly assigned. Subjects exercised on the treadmill at each of the five intensity levels while wearing one of three respirators. The three respirators were: U.S. Army M-40, full-facepiece respirator with standard inhalation (0.88 cmH20/I.Js) and exhalation (1.69 cmH20ILJs) valves; U.S. Army M-40, full-facepiece respirator with inhalation and exhalation resistances of 1.84 and 1.69 cmH20/I.Js; and U.S. Army M-40, full- facepiece respirator with inhalation and exhalation resistances of 5.73 and 1.01 cmH2QILJs. All resistances were measured at a constant flow of 85 Umin (1.42 Us). Prior to the start of each exercise session, subjects completed a five-minute warm-up period of walking on the treadmill. The treadmill was then stopped so the 94 subject could stretch. The subject was then seated and donned the respirator. Resting data was taken while the subject was seated. Subjects began exercising at 25-30% of V 02max, After a steady-state was achieved, the exercise intensity was increased to 35_ 40% of V 0 2max· This continued with exercise intensity increasing to 45-50%, 65- 70%, and 80-85% of Vozmax· Eleven of the twenty-four trials were conducted in this manner. Because of concerns that increased body temperature and oxygen drift might have been causing higher than expected oxygen consumption, the remaining subjects and trials were conducted with a slight modification. Between the third (45-50%) and fourth (65-70%) stages and between the fourth and fifth (80-85%) stages, the treadmill was stopped and the subject remained seated until oxygen consumption and heart rate returned to resting values. Subjects were given a cool-down at the end of the stage prior to stopping the treadmill and were given a wann-up prior to the subsequent stage. The time to return to baseline readings varied between subjects and depended on exercise intensity. The time the subjects were seated between stages ranged from one to five minutes. Heart rate, ECG, tidal volume, minute volume, oxygen consumption, and RPE were monitored during each testing session. The State-Anxiety test (Spielberger, 1983), a measure of situational anxiety, was administered before and after each treatment session. Subject Information Subject demographics were reported. 95 Determining Steady-State Minute Ventilation and Tidal Volume Before steady state minute ventilation and tidal volume were obtained, the work rates were checked and the possibility of the occurrence of oxygen drift was investigated. Subject variability was assessed also. Targeted Work Rates.Oxygen consumption data from the levels determination sessions were analyzed for each subject to ensure that subjects were working at the targeted work rates. Evaluation of Oxygen Drift and Subject Variability . One subject repeated the standard respirator condition three times to determine the variability in subject responses and to determine if oxygen drift was occurring. All data from stage five were plotted and a linear equation fit to the last four minutes of data (8 points). A Student's t-test was performed to determine if the slope was significantly different from zero. Steady-State Values. Oxygen consumption, minute ventilation, and tidal volume data for the four combinations of inhalation and exhalation resistance were analyzed to determine steady-state values. The last three minutes of data (6 points) from each stage were averaged to determine the steady-state value for the subject and respirator condition. The data from the eight subjects were averaged so that an 96 average tidal volume and minute ventilation for each stage and each respirator condition were obtained. Standard deviations were obtained also. Development of Equations The equations needed for the model structure were established. In some cases, existing equations were used. Where equations were not available, new equations were developed. The specific statistical procedures used to develop each equation are discussed with each equation. In general, the following statistical analysis was performed. The data were plotted and the relationship between the variables observed. A regression equation was calibrated using the method of least squares. The standard error ratio ' standard error of the coefficients, the correlation coefficient, partial regression coefficient, bias and mean bias were determined. The residuals were plotted and examined for any patterns. Percentage errors in the predictions were determined and discussed. When sufficient data were available, a regression equation was fit to validation data. A Student's t- test (hereafter referred to as at-test) was performed to determine if the coefficients in the validation equation were equal to the coefficients in the calibration equation. The significance level was a= 0.05. If sufficient data were not available for validation, the available data were plotted along the calibration regression equation and the percent errors in prediction obtained. 97 External Work Rate Equations for determining the external work rate for various activities were selected. Efficiency as a Function of External Work Rate The equations developed by Johnson (1992) for positive work rates were used. A graph of efficiency versus positive work rate was obtained. Data was obtained from Webb et al. (1988), Nagle et al. (1990), and Hambraeus et al. (1994). The data from these studies were plotted on the graph of efficiency versus positive work rate from Johnson (1992). The fit of the data to the equation was assessed using residuals and percent error. Bias and mean bias were determined also. Equations for negative efficiency were obtained. Data from Nagle et al. (1990) were used to assess the equation. A plot was obtained of negative efficiency versus negative external work rate along with the data from Nagle et al. Residuals, percent errors, bias and mean bias were calculated. A linear regression equation was fit to the data in the region where the Johnson (1992) equations did not fit well. A plot of the data points and the best fit equation were obtained. Johnson (1992) specified the bounds for each of the four efficiency equations as the points where the equations intersected. Because one of the equations was changed, the bounds of the equations for the other regions were changed. The point 98 at which the linear regression equation intercepted the equation at the upper and lower bounds was taken as the new upper and lower bound for that region. The new efficiency equations were determined and were plotted with the data from Webb et al. (1988), Nagle et al. (1990), and Hambraeus et al. (1994). Residuals, percent errors ' bias, and mean bias were determined and compared to the statistics from the previous equations. Equations for negative efficiency versus external work rate were obtained by multiplying by-2 the efficiency for positive external work rate determined from the Johnson (1992) equations. The old and new equations for negative efficiency were plotted with the data from Nagle et al. (1990). Residuals, percent errors, bias, and mean bias were calculated. Statistics from the new and old equations were compared. Data from Luthanen et al. (1987) and Gaesser and Brooks (1975) were plotted together with the new equations. Percent errors were used to evaluate the fit of the model to the data. Physiological Work Rate The physiological work rate was calculated from the external work rate and efficiency. Oxygen Consumption Oxygen consumption and respiratory exchange ratio data from Carle (1980) were obtained. Physiological work rate was calculated using the Lusk (1928) 99 equation. The data were randomly sorted. The random number generator in Microsoft Excel was used to generate a random number for each data point. The data points were sorted according to this random number. Two-thirds (340) of the data points were used for calibration while one-third (170) were used for validation. Oxygen consumption was plotted versus physiological work rate and a linear regression performed. The data and regression line were plotted. Standard error ratio, correlation coefficient, bias, and mean bias were obtained. A t-test was performed to determine if the slope and intercept were significantly different from zero. As the intercept was not significantly different from zero, a zero-intercept model was fit to the calibration data. A plot of the data and the regression line was obtained. The standard error ratio, correlation coefficient, bias, mean bias, partial regression coefficient, and standard error of the coefficient were determined. The residuals were plotted against the physiological work rate. The percentage errors were obtained. The validation data were plotted and a linear regression with a zero intercept was performed. At-test was done to determine if the slope of the validation equation was the same as the slope from the calibration equation. The critical t-value for ISO degrees of freedom and a= 0.05 was 1.976. The null hypothesis was that the slopes of the calibration and validation equations were the same. The null hypothesis was accepted if the calculated t-value was less than± 1.976. Data from Cloud (1984) were plotted on the regression line. Percentage errors were determined. 100 Anaerobic Threshold Data were obtained from studies published in the literature and from theses. Male and female, trained and untrained subjects were included. The data consisted of age, height, weight, BMI, AT% and AT, Vo2max-AT difference, and V02max in relative (ml/kg/min) and absolute (Umin) tenns. The following studies were used for calibration: Balsom (1988), Bradley (1982), Caprarola (1982), Claiborne (1984), Dwyer and Bybee (1983), Gray (1981), Jones (1984), Robbins (1982), Weitman and Katch (1979), Weitman et al. (1978), and Johnson et al. (1999). Linear regression equations relating the AT, AT%, and Vo2max-AT difference to relative and absolute Vo2max were obtained. Multiple regression equations relating the AT, AT%, and Vo2max-AT difference to age, height, weight, BMI, and relative or absolute V 02max were obtained. The two linear regression equations and two multiple regression equations with the highest correlation coefficients were selected for further statistical analysis. The standard error ratio, standard error of the regression coefficients , partial regression coefficients, and model bias were determined. The sign of the coefficients was checked for rationality. Plots of the residuals versus the independent variables were obtained. Percent errors of the model output were calculated. The number of points with errors greater than 20%, 40%, and 100% were determined. Because the number of data points differed among the equations, the percentage of points in the error ranges stated previously were calculated also. Based on the statistical analysis, one equation was selected. 101 Data from Caretti et al. (2001) and Powers et al. (1984) were used to validate the selected equation. Data from these studies were overlayed on a plot of the original data and the selected regression equation. The residuals were evaluated from this plot. Percent errors in the model predictions were determined. Minute Ventilation as a Function of Oxygen Consumption Data were obtained from the eight subjects who completed the current study. The data were obtained from the levels determination session, the initial test to determine the speeds and grades for stages one to five for the respirator conditions. A plot of minute ventilation versus oxygen consumption was obtained for each subject and a linear curve was fit to the data below the anaerobic threshold while an exponential curve was fit to the data above the anaerobic threshold. The maximum minute ventilation (VEmax) and maximum oxygen consumption (V ozmax) were determined from the V 02max test. The steady-state minute ventilation (VE) and oxygen consumption (V02) data were divided by the VEmax and Vozmax, respectively, to get the percentage of VEmax (% VEmax) and V 02max (% Vozmax). The data were plotted. Linear, quadratic, exponential, and power models were fit to the data. The following statistics were obtained for each model: SJSy, bias, mean bias, and correlation coefficient. The % V Emax predicted by each model for 100% V ozmax was determined. Based on the statistics, one model was selected. Two subjects from the current study completed the levels determination test but could not complete all the respirator conditions. The data from those two subjects 102 were used to evaluate the fit of the model. The residuals and percent errors were obtained. The data were plotted on a graph with the selected equation. Determining VEmax. The highest minute ventilation (VEmax) recorded during each subject' s test of maximal oxygen consumption from the current study was obtained. A plot of VEmax versus Vo2max was obtained. A linear regression was performed. Based on the results of the above, VEmax and V ozmax data were obtained from two other studies (Caretti et al., 2001; Johnson et al., 2001). Combining these data with the data from the current study yielded 30 data points. The data were sorted by V ozmax in ascending order. Every third data point was removed from the set and reserved for validation. The other two-thirds of the data were used for calibration. A linear regression equation was fit to the pooled data. The following statistics were obtained: Se/Sy, Se(bo)/bo, Se(b1)/(b1), t1, bias, and mean bias. A plot of the residuals was obtained. The one-third of the data reserved for validation was plotted and a regression equation found. A t-test was performed on the slope and intercept coefficients to determine if they were statistically different from the slope and intercept obtained during calibration. There were 8 degrees of freedom. The critical t-value for a= 0.05 for a two-tailed test was 2.306. The null hypothesis was that the slope (or intercept) coefficient from the validation equation equaled the coefficient from the calibration equation. The null hypothesis was accepted for -2.306 $ t $ 2.306. 103 Tidal Volume as a Function of Oxygen Consumption Plots of steady state tidal volume versus steady state oxygen consumption were obtained from the levels determination test for each of the eight subjects in the current study. The shape of the relationship between the two variables was observed. The maximum tidal volume was obtained from the V 02max test and aU steady state tidal volumes were expressed as %VTmax· A plot of %VTmax versus %V02max was obtained for each subject. The data from the eight subjects were pooled and plotted. Linear, quadratic, exponential, and power models were fit to the data and plotted. The Se/Sy, bias, mean bias, percent error of the residuals, and correlation coefficient were obtained for each model. The % V Tmax predicted by each of the four models for 100% of V ozmax was determined. Based on the statistics, one model was selected. The data from two subjects who completed the levels determination session but who could not complete the rest of the tests were used to validate the model. The data were plotted on a graph with the selected equation. The residuals and percent errors were obtained. Determining VTmax as a Function of Vo2max• VTmax values were obtained from the current study and from Johnson et al. (1999) and Caretti et al. (2001 ). The data were pooled and sorted by V 02max in ascending order. Every third data point was removed from the data set and was put aside for validation. The remaining two-thirds of the data were used for calibration. A linear regression equation was obtained for 104 th e calibration data. The calibration data and regression equation were plotted. The st andard error ratio, the standard error of the regression coefficients, partial regression coefficient for the slope, the bias, mean bias, and correlation coefficient were obtained. The residuals were plotted and the percent errors obtained. A linear regression equation was fit to the validation data. The validation data and equation were plotted. A t-test was performed to determine if the slope and intercept coefficients of the calibration and validation equations were the same. The null hypothesis was that the coefficients were the same. For eight degrees of freedom (lo samples - 2 coefficients being fit) and a= 0.05, the critical t-value was 2.306. The null hypothesis was accepted if the calculated t-values were within± 2.306. The Effects of Resistance on Minute Ventilation and Tidal Volume Average minute ventilation and average tidal volume were obtained for each of the five stages and each of the three conditions. Multiple regression equations Were obtained regressing average minute ventilation (or tidal volume) on inhalation and exhalation resistance. The standard error, correlation coefficient, and bias were obtained. Results were compared to the literature. Change in Minute Ventilation with Dead Space Minute ventilation and tidal volume data were obtained for rest and light exercise (Stannard and Russ, 1948) and heavy exercise (Johnson et al., 2000). Data 105 from Stannard and Russ (1948) were read from their Figure I. The actual values Were not presented. Linear regression equations were fit to the resting and light exercise data. Plots of the data and the regression Jines were obtained. The fo11owing statistics were caJcuJated: Se/Sy, r, bias, mean bias, and residuals. The residuals were plotted against tidal volume. A t-test was perfonned to detennine if the slopes and intercepts of the regression equations were statistica11y different. For five data points, the degrees of freedom were three (5 - 2 coefficients being fit). The critical t value for a= 0.05 for a two-tailed test was 3.182. The nu11 hypothesis was that the slopes (or intercepts) were statistica1Iy the same. This hypothesis was accepted if the critical t value was between -3.182 and 3.182. The average difference between the predictions made with the two regression equations was determined. The work rate as % V 02max was estimated for rest and light exercise. An equation relating the change in minute ventilation to dead volume and % V 02max was obtained. The multiple regression equation was evaluated using the light and heavy exercise data. Residuals and percentage errors were obtained for the light exercise data. Change in Tidal Volume with Dead Space Tidal volume and dead space values for rest and light exercise (Stannard and Russ, 1948) and heavy exercise (Johnson et al., 2000) were obtained. Linear 106 regression equations were fit to the rest and light exercise data and the following statistics were obtained: Se/Sy, r, bias, relative bias, and percent errors. The data and regression lines were plotted. Plots of the residuals versus dead volume were obtained. Work rates were estimated for rest and light exercise and were expressed as percentages of maximal oxygen consumption. A multiple linear regression equation Was fit to the data and the following statistics obtained: Se/Sy, r, bias, relative bias, and percent errors. Plots of the residuals versus % V 02max and dead volume were obtained. The regression equation was checked for rationality of predictions. Oxygen Consumption as a Function of Minute Ventilation Oxygen consumption and minute ventilation data were obtained from the eight subjects who completed the current study. These data were collected during the levels detennination session. The data were plotted and a regression equation fit to the data. The correlation coefficient, standard error ration of the model, standard error ratios of the coefficients, bias, and percentage prediction errors were calculated. The oxygen consumption residuals were plotted against minute ventilation. Data from two subjects who started but did not complete the current study Were used to validate the regression equation. The data were plotted with the regression line. Percentage errors were found. 107 Oxygen Consumption as a Function of Tidal Volume Oxygen consumption and tidal volume data were obtained from the levels determination session of the current study. The data were plotted and a regression equation fit to the data. The following statistics were determined: correlation coefficient, standard error ratio of the model, standard error ratios of the coefficients bias, mean bias, and percentage errors. The oxygen consumption residuals were plotted against the tidal volume. Validation data were obtained from two subjects who started but did not complete the current study. Their data were plotted along the regression line. Percentage errors were obtained. Actual Oxygen Consumption Actual oxygen consumption was determined using the equation for oxygen consumption as a function of minute ventilation. Oxygen Deficit Oxygen deficit was found as the difference between required and actual oxygen consumption. 108 , Performance Time Performance time was found by dividing an estimate of the maximal oxygen deficit by the oxygen deficit. Respiratory Rate and Respiratory Period Respiratory rate was found by dividing the adjusted minute ventilation by the adjusted tidal volume. Respiratory period was determined from the inverse of the respiratory rate. Exhalation Time as a Function of Respiratory Period Data from the inhalation/exhalation study (Johnson et al., 2001) were used for this analysis. Subjects in this study exercised at 80-85% of V 02max until voluntary termination while wearing one of nine combinations of inhalation and exhalation resistance. Subject files were combined so that one pooled data file was generated for each of the ten test conditions. Every third data point was extracted so that this data could be used for validation. Data from all conditions were then pooled. This resulted in a data set of 4396 pairs of data for the calibration and 2191 pairs of data for the validation. A plot of exhalation time versus respiratory rate was obtained. A change of variable was made to linearize the equations and simplify the statistical analysis. The exponents in the power-law models that resulted from regression of exhalation time 109 against respiratory rate were close to -1. Therefore, there should be a nearly linear relationship between exhalation time and the inverse of the respiratory rate. The inverse of the respiratory rate is the respiratory period. Therefore, exhalation times were plotted against respiratory period. A linear regression was obtained. The following statistics were determined: r, Se/Sy, Se(bo)lbo, Se(b1)/b1, and model bias. The residuals were plotted against the respiratory period. Percent errors of the residuals were obtained. The one-third of the data reserved for validation was plotted and a regression equation detennined. At-test was pertormed to determine if the slope and intercept of the regression on the validated data was the same as the slope and intercept of the regression on the calibration data set. For n = 00, the critical t-value for a= 0.05 for a two-tailed test was I.96. The null hypothesis was that the slope (or intercept) coefficient from the validation data equaled the slope (or intercept) coefficient from the calibration data. The null hypothesis was accepted if the calculated t-value was less than 1.96 and greater than -1.96. Breathing Wavefonn Based on Work Rate Work rates at which the transitions between waveforms occur were estimated. Respiratory Work Rate Respiratory work rate equations were obtained from Johnson (1993). Inhalation and exhalation work rates were determined separately. The work of 110 inhalation and exhalation was determined by multiplying the work rate by the corresponding time (inhalation or exhalation). The total respiratory work was found by adding the inhalation and exhalation work. Total respiratory work rate was calculated by dividing total respiratory work by the respiratory period. Implementing and Evaluating the Model The model was implemented in Visual BASIC. The program was structured so that future development of the model could be incorporated easily. Calculations were placed in functions so that the program was modular. Changes to the flow of the main section of the program would not affect those functions. Additional functions could be added easily. Three stages of model eva]uation were conducted. The first stage involved checking the accuracy of the ca1culations performed by the model. In the second stage, data from several subjects were used to evaluate the accuracy of the model. The third stage involved running simulations of the model at several work rates with and without a respirator and evaluating the results. Model Equations The programmed equations were checked to be sure they were entered correctly. By far the most complicated equations were the respiratory work equations developed by Johnson (1993). Values for minute ventilation and inhalation and 111 exhalation times were provided in the paper for rest, and light, moderate, heavy, and very heavy exercise. Results of the work rate model were given for the individual Work rate components for inhalation with sinusoidal, trapezoidal, and hybrid exponential waveforms during light exercise. Additionally, the total work rate of inhaling and exhaling with sinusoidal , trapezoidal, and hybrid exponential waveforms at rest and during light, moderate, heavy, and very heavy exercise were given. Data Were given also for the individual work components for exhaling with the limited- flow hybrid exponential. The input values given in the paper were entered into the current model and the results compared to the results presented in Johnson (1993). Other equations in the model were checked by calculator and by spreadsheet to ensure that mistakes had not been made either in entering the equations or in the l . . ogic that dictated their use. Subject Simulations Data from three subjects for the current study were used to evaluate the model output. One subject (224) completed stages one to five of the levels determination session and stages one to four of respirator condition A. The second subject (230) completed stages one to four of the levels determination session and stages one to three of respirator condition A. The third subject (002) participated in the current study. Data for this subject was rejected for two stages because the work rates were not in the targeted range. Data from one of the rejected stages was used here. 112 Additional data were obtained from three subjects who participated in an inhalation/exhalation resistance study (Johnson et al., 2001b). Nine combinations of resi stances were used. The inhalation resistances (a, b, and c, respectively) were 1.s4, 5.73, and 17.07 cmH20/Us while the exhalation resistances (d, e, and f, respectively) were 1.01, 1.69, and 4.75 cmH20!Us. The subjects were not able to achieve a steady-state for all of the test conditions. Subject 145 reached a steady- state for all conditions except cf. Subject 214 attained a steady state for all conditions except af and ed. Finally, subject 216 reached a steady-state for all conditions except af, bd, ce, and cf. The subject's weight and Vo2max, the treadmill speed and grade for the test, and the respirator characteristics were entered into the model and a simulation was run. Model simulation data were plotted against the measured value and a line of identity. These plots were obtained for oxygen consumption, minute ventilation, and tidal volume. The percentage errors were obtained. Based on results from the three subjects who completed part of the current study, adjustments to the model were made. The Pandolf et al. (1977) equation was used to calculate physiological work rate. The relationship between physiological work rate and oxygen consumption was re-evaluated. Oxygen consumption data from the eight subjects who completed the current study were used in the evaluation. Physiological work rates were calculated from the Pandolf et al. (1977) equation. The data were plotted and a linear regression perfonned. The following statistics were obtained: correlation coefficient, standard error ratio, bias, standard error of the coefficients. 113 Simulations were run again using the new methods. Calculated parameters were plotted against the associated measured parameters and a line of identity. Percentage errors were obtained. Results were compared to those obtained before the changes. Mask I No Mask Simulations Treadmill speeds and grades were determined for work rates in the ranges 25- 30%, 35-40%, 45-50%, 65-70%, and 80-85%. These work rates were chosen to correspond to the work rates in the current study. An additional simulation was run at an external work rate of zero achieved by setting the treadmill speed and grade to zero. The U.S. Army M40 respirator was selected for the mask simulations. Other than changing the mask and the treadmill speed and grade, all other inputs remained at their default values. The program was run at rest and the five work rates for the no mask and mask conditions. Output files were generated for each simulation. Plots of adjusted minute ventilation, adjusted tidal volume, adjusted oxygen consumption, respiratory rate, inhalation time, exhalation time, inhalation work rate, exhalation work rate, inhalation work, exhalation work, total respiratory work, and total respiratory work rate versus percent of maximal oxygen consumption were obtained. The %Ymmax was based on the required oxygen consumption instead of the oxygen consumption adjusted for respirator mask resistance and dead volume so that direct comparisons between the mask and no mask conditions could be made. 114 RESULTS AND DISCUSSION The model was developed in four stages. During the first stage, the model st ructure was selected. Experimental data were obtained during stage two. The third stage involved selecting and developing equations for the model. The model was implemented in Visual BASIC and tested. 8tructure of the Model The structure of the model is shown in Figure 1. The aim of the current model Was to predict the effects of a respiratory protective mask on a person during physical activity. Resistive loads have a number of effects on respiration. Respiratory rate decreases and inhalation and exhalation times increase (Johnson, 1991). Minute ventilation and oxygen consumption decrease (Johnson et al., 1999; Caretti et al., 2001; Flook and Kelman, 1973; Hennansen et al., 1972; Silvennan et al., 1951). Other effects are important as well. Tidal volume may increase due to the dead volume of the respirator (Stannard and Russ, 1948). Respiratory work increases with increases in work rate and with the addition of a respirator (Johnson, 1991; Johnson , 1992). The decreased oxygen consumption would indicate that an oxygen deficit existed. As the current model will fonn the framework for future modeling efforts to predict the perfonnance time of respirator wearers during physical activity, oxygen 115 Input Data External Work Rate Muscular Efficiency Internal Work Rate Oxygen --- Consumption (required) Anaerobic Threshold Minute Volume Minute Volume (resp.) Respiratol)' Rate lnh. Time lnh. Resp Work Exh. Time Exh. Resp. Work Tidal Volume Tidal Volume (resp.) Tidal Volume (dead vol.) Oxygen Consumption (resp.) Oxygen Deficit Performance Time Resp. Work (total) Figure 1. Flowchart of the model of the effects of a respirator on the pulmonary system during physical activity. 116 deficit would be an important factor to consider. An estimate of performance time could be made by dividing the maximum oxygen deficit by the oxygen deficit of the activity. This might not provide a very accurate indicator of performance time, but wo·Jld provide the structure for future development of the model. While it was not necessary to calculate respiratory work to determine the effects of the respirator on breathing parameters such as oxygen consumption and minute ventilation, it was felt that the addition of respiratory work calculations would aid in the understanding of the effects of the respirator on pulmonary function. The outputs of the model were chosen to be oxygen consumption, minute ventilation, tidal volume, oxygen deficit, performance time, respiratory rate, inhalation and exhalation times, and respiratory work. In order to determine these parameters, a number of inputs were required. The output parameters were affected by the external work rate, subject characteristics, respirator characteristics, and respiratory system characteristics. The subject characteristics were age, height, weight, and maximal oxygen consumption. Respirator characteristics included inhalation and exhalation resistances, mass, and dead volume. Respiratory system characteristics included additional dead volume and resistance. Parameters of the model may be affected also by race/national origin, anxiety level, drugs, circulating honnones, and body temperature. Physical activity begins at a certain external work rate. There is an efficiency associated with that work rate and the activity being performed. An amount of physiological work must be done by the body to generate the external work. The amount of oxygen required by the body is dependent on the physiological work rate. 117 From the oxygen consumption, minute ventilation and tidal volume can be determined. Respiration rate is found by dividing minute ventilation by tidal volume. Inhalation and exhalation times can be found from the respiration rate. Respiratory Work rate depends on minute ventilation and inhalation and exhalation times. When a respirator is worn, the minute ventilation, tidal volume, and oxygen consumption are altered. An oxygen deficit results and petformance time is affected. This process Jed to the model structure shown in Figure 1. 118 Experimental Testing Experimental testing was conducted in order to obtain data for stage three, the development of equations for the model. Sufficient data were not found in the literature to develop equations to detennine the effects of respirator resistance on minute ventilation, tidal volume, and oxygen consumption during work between 25 and 80% of maximal oxygen consumption. Subject Demographics Subjects who participated in any study in the Human Performance Lab were assigned a subject number. Subjects who had completed testing previously retained the same subject number. So, subject 023 was the twenty-third subject tested in the lab under the current numbering system. Therefore, non-consecutive subject numbers did not indicate missing data, but instead indicated the order in which the subjects Started testing in the Jab. Subject infonnation for the eight subjects in the current study is shown in Table 3. Subjects 224 and 230 could not complete all the testing sessions; their data were not included. 119 -emographic information for the eight subjects in the current study. Height Mass Age Gender Vo2max Vo2max AT STAI Table 3 D Subject '--- (cm) (kg) (years) (Umin) (ml/kg/min) (%) Trait ._001 172 95 38 M 4.42 48.4 92 28 002 160 58 34 F 2.38 41.0 78 46 023 163 47 31 F 2.06 43.8 76 48 L.145 175 92 30 M 3.53 38.4 80 44 173 183 75 29 M 3.17 42.3 85 21 _214 178 77 20 M 4.97 64.5 64 38 221 178 75 23 M 4.7 62. 7 68 35 231 171 61.7 23 F 2.56 41.5 70 41 ~Mean 172.5 72.2 28.5 3.47 47.8 77 37.6 ~.D. 7.8 15.9 6.1 1.12 10.l 9 9.3 The anaerobic thresholds given in Table 3 are generally higher than expected (Weitman et al., 1978). The subjects were generally fit although only subject 001 was actively training. The other subjects participated in recreational sports usually involving hiking, biking, and jogging two to three times per week. Determining Steady-State Minute Ventilation and Tidal Volume The work intensity expressed as percentage of V 02max at each of the five stages is presented in Table 4 for each of the eight subjects. Table 4. Work intensities for each of the eight subjects in the current study expressed as % V02max. The targeted ranges for the five stages were: 25-30%, 35-40%, 45- 50% 65 70<¾ d 80 85<¾ ......::...:. , - o,an - o. ._ Subject Stage 1 Stage 2 Stage 3 Stage 4 Stage 5 ._201 39.5% 48.3% 69.2% 83.3% .._002 21.4% 30.25% 43.9% 60.1% 72.2% f---023 28.6% 37.3% 52.2% 70.3% 81.1% 145 29.0% 35.3% 45.6% 62.2% 82.3% - cJ73 30.2% 38.9% 49.3% 70.7% 82.2% .._214 29.9% 38.1% 45.0% 68.2% 79.1% 221 23.9% 38.2% 45.7% 70.5% 82.1% >--- 231 26.0% 38.5% 47.3% 69.6% 86.1% '--- 120 For b' su ~ect 002, the work rates for stages 1, 2, 4, and 5 were not in the targeted range. The stage two data was moved to stage one, while the stage 5 data was moved to stage 4. There was then missing data for stages two and five. Subject 001 had a hard time maintaining constant breathing during stage one; a steady-state value was not determined. Evaluation of Oxygen Drift and Subject Variability In subject 145 's first respirator session the subject performed stages one to five without a break. Because of concerns of the possibility of oxygen drift occurring at the higher work rates, the test was repeated twice with the subject getting break periods and returning to resting oxygen consumption levels before starting the next stage. (See Appendix B, Figures 64 to 66) A regression line was fit to the last four minutes of data from stage five for each of the three tests (see Appendix B, Figures 67 to 69). None of the slopes was statisticaIIy significantly different from zero at the a= 0.05 level. In fact, the probability levels for the three tests were 0.19, 0.30, and 0.46. Thus, oxygen drift was not occurring during the testing. Only stage five was evaluated because at that stage the given subject was slightly above the anaerobic threshold. The slow component of oxygen consumption as defined by Poole and Richardson (1997) only occurs above the anaerobic threshold. These authors stated that the onset of the slow component occurred 80 to 100 seconds after the start of exercise in this domain. While other researchers such as 121 Kearon et al. (1991) have found increases in oxygen consumption at work rates below th e anaerobic threshold, these increases were more likely due to oxygen drift rather th an the slow component of oxygen consumption because the sessions lasted for sixty minutes. The steady-state values determined from the short stages in the current study corresponded to the initial steady state in the two-exponential transient response of oxygen consumption reported by Barstow and Mole (1991). This was the steady state for the fast component of the oxygen response. The rest periods between stages were instituted because of the results of Kearon et al. (1991). Although oxygen drift was not detected, subjects in later tests completed stages one to three and then took a break until oxygen consumption returned to resting values. Stage four was completed and then the subject took a break and returned to baseline before completing stage five. The variability in the oxygen consumption response was evaluated also from the three repeated tests. The average oxygen consumptions for the five stages are shown in Table 5. Table 5. Oxygen consumption values (Umin) for subj~ct 145 during three repeated tests of the standard respirator condition. Percentage differences be~ween the first and second, first and third, and second and third tests are presented m the last three columns - __§tage Test 1 Test 2 Test 3 1 to 2 1 to 3 2 to 3 ~ 1 1.04 1.17 1.14 12.7 10.3 -2.1 - 2 1.23 1.36 1.32 10.6 7.1 -3.2 3 1.80 1.89 1.82 1.8 0.8 -3.8 '--- 4 2.7 2.69 2.56 -0.2 -5.4 -5.1 '---. 5 3.59 3.53 3.33 -1.6 -7.4 -5.9 '--- 122 Slightly larger differences occur at the lower work rates. This is not unexpected; changes in gait and arm movements at low work rates affect oxygen consumption more than at high work rates. The variability between tests was evaluated to determine the amount of variability that might be expected in a person's performance. This subject did not have much variability between test sessions. Steady-State Values Four respirator conditions were evaluated. The first was the half-mask used during the test to determine treadmiJJ speed and grade for each stage. This test session wiJJ hereafter be referred to as the levels determination session. The inhalation and exhalation resistance were 0. 7 and 0.8 cmH20/Us, respectively. The dead volume of the mask was approximately 125 mL. Respirators A, B, and Chad inhalation and exhalation resistances of 0.88 and 1.69, 1.84 and 1.69, and S. 73 and l .O 1 cmH20JUs. The approximate dead volume of each of these three respirators Was 300 mL. The average steady-state minute ventilation and tidal volume values for each respirator condition are shown in Tables 6 and 7. Table 6. Steady state minute ventilation (Us) for stages one to five for each of the three · v 1 rt d means+ one standard deviat' . - respirator conditions. a ues repo e are - ion _§tage Half-Mask Respirator A Respirator B Respirator C 1 0.35 + 0.11 0.33 + 0.09 0.33 ±0.08 0.33 ± 0.08 ,...__ 2 0.46 + 0.12 0.44 + 0.12 0.44 ± 0.11 0.44±0.11 -3 0.57 + 0.17 0.53 + 0.16 0.51 ± 0.15 0.53 ±0.14 -4 0.79 ±0.23 0.80 ±0.22 r-- 0.89 +0.27 0.83 +0.28 5 1.28 + 0.46 1.22 +0.45 1.12 ± 0.36 1.05 ± 0.28 - 123 Table 7. Steady state tidal volume (L) for stages one to five for each of the three respirator conditions. Values reported are means+ one standard deviation. Stage Half-Mask Respirator A Respirator B Respirator C l 0.59 + 0.24 0.72 + 0.26 0.66 + 0.22 0.65 + 0.21 2 0.80 + 0.28 1.00 + 0.38 0.98 + 0.37 0.89 + 0.27 3 1.03 + 0.40 1.15 + 0.47 1.06 + 0.37 1.02 + 0.35 4 1.47 + 0.55 1.50 + 0.52 1.48 + 0.43 1.46 + 0.43 5 1.84 + 0.57 l.91 + 0.64 l.89 + 0.58 l.78 + 0.34 124 Development of Equations During this stage, equations were determined to fill in the model structure. Existing equations were used if they were available. If not, new equations were developed. A summary of the equations used in the model is shown in Table 8. Units for the equations and descriptions of the variables are found within the text. 125 Table 8. ~ummary of the equations used in the model. See the text for explanations of the van ables and the units. Numbers refer to equations within the text. External Work Rate distance cadence · load ·----· g WR = revolution ext 60 WR,w = hsrcp. mass· nsrep . g G WR = m ·g·v ·- exr t IOO (3) (4) (6) Efficiency as a Function of Work Rate t/ = WRW 200 r,=O.I003+0.0006(WRexl -20.1) f/= 0.183 + 0.0002(WRext -159.3) f/= 0.2 0 5 WRext < 20.1 (48) 20.J 5 WRext < 159.3 (49) 159.3 5 WRext < 240 (50) 240 5 WRext (51) f..hysiological Work Rate WR = WRCXI (52) phys t/ Qxygen Consumption as a Function of Physiological Work Rate V02 = 0.002952WRphys (55) .Anaerobic Threshold as a Function of Maximal Oxygen Consumption AT= 0.8624V02max - 7.1585 (58) Minute Ventilation as a Function of Oxygen Consumption %VEmax =0.0095·%V 202max -0.133 •%V02max +17.153 (69) VEmax = 20.01Vo2max +27.855 (70) .Tidal Volume as a Function of Oxygen Consumption % VTmax = 0.9987 • % Yo2max -1.6809 (72) VTmax = 0.3864 · v02nulx + 0.6416 (73) 126 £bange in Minute Ventilation with Resistance 25-30% V 02max: VE = 0.3705-0.0037Rinh -0.02236Rexh (75) 35-40% Vo2max: VE = 0.4754-:--0.0018Rirlh -0.0206Rexh (76) 45-50% Vo2max: VE =0.6088-0.0065Rinh -0.0469Rexh (77) 65-70% Vo2max: VE =0.9718-0.0156Rinh -0.0846Rexh (78) 80-85% Vo2max: VE= 1.3979-0.0454Rinh -0.0967Rexh (79) £hange in Tidal Volume with Resistance 25-30% Vo2max: VT =0.5023 +0.0059Rinh +O.I046Rexh (80) 35-40% Vo2max: VT =0.6271+0.0092Rinh +0.2080Rexh (81) 45-50% V 02max: VT = 0.9698 - 0.0091Rinh + 0.0890Rexh (82) 65-70% Vo2max: VT= 1.4525-0.0027Rinh -0.0024Rexh (83) 80-85% Vozmax: VT =1.7955-0.0162Rinh +0.0746Rexh (84) £.bange in Minute Ventilation with Dead Volume (%Vo2max -0.15) (I.BJ .1VE =0.170432V0 -0.00681- O.l5 · 60 £bange in Tidal Volume with Dead Volume 0.4256% V 02max .1VT = 0.1950+ 0.2517VD - IOO llivgen Consumption as a Function of Resistance and Dead Volume V02 = 0.0340VE +0.4322 lli,vgen Deficit 0 2 de fi Cit = Vo2,requircd - V 0 2.adjusted 127 (87) (90) (91) (93) &.,,rfonnance Time P rf . ( 4.03 ] e time= 0 2 deficit lkwiratory Rate VE d' RR = · ,a 1us1ed V T,adjusrcd &spiratory Period l RPD=- RR fuhalation Time as a Function of Respiratory Period Tcxh = 0.6176RPD-0.2145 128 (94) (95) (96) (97) Extemal Work Rate Equations for determining external work rate for walking or running, stepping, and cycling were discussed previously. Equations 3, 4, and 6 were selected for cycling, stepping, and walking, respectively. These equations were: distance cadence· load·----· g WR = revolution ext 60 WRex1 = h step ·mass· n step • g G WR =m ·g·v·- ext t lOO Efficiency as a Function of External Work Rate (3) (4) (6) A series of four equations (equations 9 - 12) were developed by Johnson ( 1992) that related gross efficiency to external work rate. Equations were developed for ranges of Oto 10 w, 10 to 140 W, 140 to 240 W, and 240 W or greater. Data from the literature were used to assess these equations. If an equation for one, or more, of the ranges did not fit well, a new equation was developed for that region or regions. A plot of the data and the Johnson (1992) equation is shown in Figure 2. Data Were taken only from studies that used direct calorimetry because indirect calorimetry Was used in a later part of the model. Using indirect calorimetry to fit the curve for efficiency would preclude its use in fitting curves in the latter part of the model as 129 -w 0 25.00% -r-----------------------------------------, 20.00% ------ - - -- - -- --- - - - - -----~ ~:::::::::=- ---------; ~ 15.00% ..._, >, u c:: 0 ·u • --Johnson (1992) s ~ 10.00% - -· --- • Webb et al. (1988) cycle ~ Hambraeus 29yo X Nagle et al. (1990) 5.00% - 0.00% ~. -----~----------~-----------~------------ 0 50 100 150 200 250 300 External Work Rate (W) Figure 2. Efficiencies from three studies plotted against external work rate and the equations developed by Johnson (1992). 350 parameters in latter parts of the model will be based on values from the efficiency equation. Only one data point was available in the region from Oto IOW and this was for OW where efficiency is 0%. No direct calorimetry points were available for work rates greater than 240W. In the 140-240 W range, there were two data points. The percent errors of these two points were -1.12 and 1.76%. While the errors were small, both data points were obtained from one subject at the same work rate of 200W. So, the equation fits well for this one subject, but not much else can be said about the equation. In the 10- 140 W range, there were five data points. The percent errors for these points were 30, 21, 7.6, 4.5, and -2.5%. So, for four of the five data points the equation over-predicts the efficiency. The bias of the model in this region was 0.09 While the mean bias (bias divided by y-mean) was 0.61. Both of these criteria indicated that the model was biased. Again, with so few data points, not too much can be said about the fit of the equation. If more data were available, it is possible that due to the variability of physiological data, the equation may actually under- predict. However, using the only data available, it seemed that the equation for the IO to 140 W range (equation 10) should be changed. The five data points that were in the 10 to 140 W region and the linear regression line fit to these data are shown in Figure 3. The equation was: 1] == 0.0006 • WRext + 0.0883 (47) 131 -w N 18.00% • 16.00% 14.00% ~ 12.00% ,-._ ~ ';:, 10.00% 0 c:: cu ~ 8.00°/c ~ 0 6.00 % 4.00 % 2.0 0% 0.0 0% ~ • 0 20 40 60 80 External Work Rate (W) Figure 3. Best fit line through efficiencies for work rates of 10 - 140 W. 100 __,,,,--, • 120 140 A plot of equation 47 with the equations for the other regions is shown in Figure 4. The intersections of equation 47 with the equations of the two adjacent regions were found. The intersection between equation 47 and the equation for the range 140 to 240 W was 159.3 W, the upper bound for equation 47. The lower bound of the region for equation 4 7 was 20.1 W. The resulting equations for efficiency versus external work rate were: n_ WRexr .,-- 200 1J=0.1003+0.0006(WRexl -20.1) 'YJ = 0.183 + 0.0002(WRext -159.3) 1]=0.2 0 ~ WRext < 20.l (48) 20.1 ~ WRext < 159.3 (49) 159.3 :5 WRext < 240 (50) 240 ~ WRexr (51) The plot of equations 48-51 and the data are shown in Figure 5. The errors for the five points in the region 20.l to 159.3 W were 9.6, 14.5, 2.1, -18.l and -2.2%. The bias of the model for this region was reduced from 0.090 to 0.018 while the mean bias was reduced from 0.61 to 0.12. The fact that the bias was still negative indicated that the model continued to over-predict the efficiency in the range. However, the bias and mean bias were decreased by 80%. Thus, equation 49 fit the data more accurately than did equation 10. 133 25.00% ~------------------------------------------, ~ 15.00% +----------------------------------------- -------1 .._, ::>-. g 0 ·u e 1.:Q 10.00% +--~,::__---~------- - - - - ------------ - - - - - - - -----1 0 50 100 150 200 250 300 350 External Work Rate (W) Figure 4. Intersection of the new regression line through the Johnson (1992) equations. -w VI. 25.00% --.----------------------------------------------, ~ 15.00% +----- -----~rc-------- - --------------------------1 '-' ;>-. u C: ~ ·n t.;::: t'.a 10.00% +--..--,:C'------ --- - - ------ - - -------- --------------------1 5.00% +--------------------------------- - - ------ - -----1 0 .00% -r-----.------r------......,-------,-------,------.------,.------1 0 50 100 150 200 250 External Work Rate (W) Figure 5. Data plotted against the new set of efficiency equations. 300 350 400 The study conducted by Johnson et al. (2001a) showed that the efficiency of negative work was equal to -2 times the efficiency for positive work. Therefore ' negative efficiency was obtained by multiplying by-2 the efficiency for positive external work rate determined from the Johnson (1992) equations. A plot of the Johnson (1992) equations and two negative efficiency data points are shown in Figure 6 - Both the negative efficiency and work rate are plotted as positive values. The percent errors for these two points were -1 and 33.6%. The Johnson (1992) equation under-predicted the efficiency. A plot of the two negative efficiencies with the new equation is shown in Figure 7. The errors for the two points were 25 and -34%. The bias was decreased from -0.16 to -0.12 while the mean bias was reduced from -0.47 to-0.34. So, the equation stiH had a bias, but it was smaHer. Further statistical analysis with such a smaH data sample was not warranted. However, efficiencies from two studies (Luhtanen et al., 1987; Gaesser and Brooks ' 1975) that calculated internal work rate were used to evaluate the fit. The data are plotted with equations 48-51 in Figure 8. The two studies were not used in calibrating the model because the calculated internal work rates were used later in the development of the model. The percent errors for the Luhtanen et al. (1987) data ranged from -15 to 11 %. The ranges of percent errors from the Gaesser and Brooks (1975) data for 40, 60, 80, and 100 rpm were 10 to 25%, 11 to 23%, -6 to 16%, and -42 to 3%, respectively. So, the equations seemed to provide reasonable predictions 136 60.00% -.-- -------- ---- -------- --- ---------------, 50.00% - • ,-.. * 40.00% --- .._,, >, 0 C: cu ·u t;: .... 30.00% - ---------------- ------------------1 Ul cu ~ ·p - Johnson (1992) c:,s ..... bl) l..>l cu 20.00% - -..l z • Nagle et al. (1990) 10.00% -4--# - ---------------------- ------------------t 0.00% ------..-- ---.--- -- - - ---- ---- ----.--- -----,- ----,.---- --1 0 50 100 150 200 250 300 350 400 Negative External Work Rate (W) Figure 6. Negative efficiencies plotted with the Johnson (1992) regression lines. -'->J 00 60.00% ~------------------------------------------, 50.00% - ·- - -·- · ,-._ * ..__, 40.00% - -- - - ------- >-> u C ~ ·u t;:: 30.00% (ij -------·· - -- --- ~ > ..... Cl:! ~ 20.00% - - - z 10.00% - . --- --- - ---- - --- -- ------- ------------- ------- - • ==:,:::::::.;;---------- - \ -equation \· \ • Nagle et al. (1990) _ 0.00% ------...,......-----,-----~------.-----...-------.-------,------ 0 50 100 150 200 250 Negative External Work Rate (W) Figure 7. Negative efficiencies plotted with the new regression lines. 300 350 400 25.00% ....-------------------------------------------, 20.00% ~ 15.00% '-' >-, u ~ cu ·u t.::. ~ 10.00% - - 5.00% • • -equation • Luhtanen et al. (1987) ~ Gaesser & Brooks 40rpm x Gaesser & Brooks 60rpm x Gaesser & Brooks 80rpm • Gaesser & Brooks 100rpm 0.00% +------r------r------,-------,------,------,------,------; 0 50 100 150 200 250 300 350 400 External Work Rate (W) Figure 8. Efficiency data from the literature plotted with the new regression lines. of efficienc b Y ased on external work rate when looking at a limited number of data points. Ph · yszological Work Rate Physiological work rate was found by dividing the external work rate by the efficiency: WR - WRext phys - 17 (52) where: WRphys, physiological work rate, W If the external work rate is zero, the model assumes zero efficiency, and a Physiological work rate equal to the basal metabolic rate. However, if the person is running on level ground, the person has a physiological work rate much higher than basal metabolic rate. For these cases, the physiological work rate was calculated. Pandolf et al. ( 1977) provided an equation for determining physiological work rate for subjects who were walking or standing with or without loads on different types of terr · arn. The authors and other independent researchers (Myles and Saunders, 1979) found good agreement between predicted and measured values. The equation was: WR phys = 0.15Wb + 0.20(Wb + W,XWb/W,)2 +0.102((Wb + w1X1.sv 2 +35vG/100)-(wb + wl)vG/100 (53) 140 where: Wb, body weight, N Wi, total load weight, N s. terrain coefficient, dimensionless Terrain ff' . . coe 1c1ents varied from 1.0 for treadmiJJ or blacktop surfaces to 2.1 for loose sand. Oxygen Consumption Originally, the intent was to substitute the Johnson (1992) equations relating respiratory exchange ratio to oxygen consumption and V 02max into the Lusk ( 1928) equation relating physiological work rate to respiratory exchange ratio and oxygen consumption. The Johnson (1992) equations specified three equations for RER. The selected equation depended on the % Vozmax· Thus, the oxygen consumption must be known to determine which equation to use. The three quadratic equations could be solved for the oxygen consumption based on the physiological work rate, Vozmax, and %Vo2max, The problem was that in order to determine %Vo2max, the oxygen consumption was needed. Another way to determine the oxygen consumption was needed. Astrand and Rodahl (1970) showed that the oxygen consumption was a linear function of the physiological work rate (their Figure 13-2). Based on that figure, a regression was performed relating oxygen consumption to physiological work rate (see Appendix B, Figure 70). The regression equation was: 141 Vo2 == 0.002977WRphys -0.01748 where: V 02, oxygen consumption, Umin WRphys, physiological work rate, W (54) The correlation coefficient was 0.994. The standard error ratio was 0.109, indicating th at equation 54 provided better predictions than predictions made with the mean. The bias and mean bias were zero. The results of the t-test indicated that the slope coefficient was significantly different from zero, but that the intercept coefficient was not significantly different from zero. Because the intercept was not different from zero a z . d , ero-mtercept model was use . The zero-intercept regression equation was: (55) A plot of the data and regression line is shown in Figure 9. The correlation coefficient was 0.994. The standard error ratio was 0.11. If the Sc is less than Sy , then the model makes better predictions of the y-variable than the mean. If the standard error ratio s IS is close to zero a significant improvement in prediction , e y, , accuracy has occurred. Thus, predictions made with equation 55 were better than Predictions made with the mean. The bias was -0.07 and the mean bias was -0.03. Thus, the model tends to under-predict. The adjusted correlation coefficient was 142 -~ w 3~--------------------------------------, 2.5 ,-... C ·e ~ .._, C .2 .... 0... E :, "' C 0 u C cu 00 >-, X. 0 2 1.5 1 0.5 04-----------~---~---~---~---~-------~--- 0 100 200 300 400 500 600 Physiological Work Rate (W) Figure 9. Calibration data and the zero-intercept regression line. 700 800 900 1000 o. 9Bs. The standard correlation coefficient assumes a model with a zero bias. The adjusted correlation coefficient is a more accurate measure of the model's goodness of fit if there is a bias. A correlation coefficient (standard or adjusted) of one indicates a perfect fit. So, the adjusted correlation coefficient indicated that there was a high degree of fit even though there was a small bias. The partial regression coefficient was 0.986. Values close to one indicate an Important predictor. The standard error of the coefficient was 0, indicating that the slope coefficient was an important predictor. From the plot of the residuals it appears that the error became larger as physiological work rate increased (see Appendix B, Figure 71). The percentage errors were between -1.9% and 4.6%. So, overall , equation 55 provided accurate predictions of oxygen consumption based on physiological work rate. The zero-intercept model fit to the validation data was: V02 = 0.002947WRphys (56) A plot of the data and the regression line are shown in Figure 10. The correlation coefficient was 0.9949. The calculated t-value was --0.024. As this value was less than± 1.976, the critical t-value, the null hypothesis was accepted. That is, the slopes of the calibration and validation equation were the same. 144 3~-------------------------------------------, 2.5 "2 ·e 2 :::l .._, C .9. 0.. E 1.5 :J "' C 0 u C 0 Oil 1 >. - >( ~ 0 U\ 0.5 0 +-----,--------.-----.-----,-----.......------,-----,-------.-------,-------1 0 100 200 300 400 500 600 700 800 900 1000 Physiological Work Rate (W) Figure 10. Validation data and the regression line. The plot of the data from Cloud (1984) and the regression line is shown in Figure 11. The data lie along the line and slightly below it. It appeared that equation 56 under-predicted the data. However, the percent errors ranged from -1.4% to 6.6%, so the errors were very small. Astrand and Rodahl (1970) showed that the oxygen consumption was a linear function of the physiological work rate. Their graph provided the idea for relating oxygen consumption to physiological work rate only. An equation fit to their data revealed a slope of 0.002936, which is very close to that obtained in equation 55. Equation 55 does not directly take the respiratory exchange ratio into account. However, it does provide accurate predictions of oxygen consumption based on physiological work rate and it agrees with the information presented in Astrand and RodahJ (1970). 146 3.5 ~-----------------------------------------, ~ 2.5 ~ C -~ 2 -+---------- -------- ----- 0.. E :::l "' C 8 1.5 C ~ >. >( 0 0-+-------..--------,---------.--------,-------...-----------i 0 200 400 600 Physiological Work Rate (W) 800 1000 Figure 11. Data from a validation study plotted along the regression line for the zero-intercept model. 1200 Anaerobic Threshold Some studies (Dwyer and Bybee, 1983; Rusko et al., 1980; Thorland et al., 198 0; Weltman and Katch, 1979) had shown a relationship between anaerobic t bresho Id ( AT) and maximal oxygen consumption. It was desired to see if there were th e same relationship for a larger group of subjects. The percentage of maximal oxygen consumption at which the anaerobic threshold occurs (AT%) and the djfference between maximal oxygen consumption and the AT (V o, .. ,-A T) were considered also. Oxygen consumption and anaerobic threshold were considered in both relative (mUkg!min) and absolute (Umin) tenns. As the AT has been shown to be related to fitness level ( Claiborne, 1984 ), the possibility that AT may be related to Other factors such as height, weight, or body mass index (llMI) was evaluated using rnultiple regression. The equations resulting from the linear and multiple regressions are shown in Tables 9 and 10. Table 9. Linear equations obtained from relating AT%, AT, and Vo2max-AT difference (Diff) to relative and absolute oxygen consumption. Relative oxygen consumption is in units of ml/kg/min, while absolute oxygen consumption is in Umin ~· Equation Number of Equation R _Qnits Cases Relative 120 AT% - 0.3682 V 02max + 52.935 (57) 0.3006 -r-B_~ative 120 AT 0.8624 Vo2max - 7.1585 (58) 0.8305 Jselative 120 Diff 0.1376 Vo2max + 7.1585 (59) 0.2314 ~Jolute 168 AT% 0.6462 Vo2max + 62.275 (60) 0.0435 ~bsolute 168 AT- 0.6083 Vo2max + 0.1445 (61) 0.7964 , Absolute 168 Diff 0.0632 Vo2max + 1.2054 (62) 0.0511 148 lable 10. Multiple regression equations obtained from stepwise regression of AT% . T, and V 02max-AT difference (Diff) on age, height, weight (WT), BMI and Vo ' m I . , ""'' re at, ve and absolute terms. Relative oxygen consumption is in uni ts of ml/kg/min while ab J t LJ · ' - sou e oxygen consumption is in rrun. Equation I Number Equation R Units of '-------- Cases '-Relative 120 AT% - 92.4782 - 0.3585WT (63) 0.3873 (64) 0.7356 - ._B_elative 120 AT= 13.8534 + 0.625Vo2max -0.1661WT Diff- -13.8534 + 0.3750Vo2max 0.1661WT (65) 0.5627 Relative 120 L Absolute 168 AT%= 78.427 + 6.0138 Vo2max - 0.3836WT (66) 0.4755 AT= 0.0297 + 0.7156Vo2max (67) 0.7320 Absolute 168 L Absolute 168 Diff = -2.0768 + 0.59IOV02max -0.0771 WT (68) 0.8125 Equations 58, 61, 64, and 68 were selected for further statistical analysis. The results are summarized in Table 11. Table 11. Results from statistical tests to evaluate competing models. The intercept of the linear equation is noted with the subScript O while slope coefficients are noted with th b · 1 (V ) d 2 (WT) 02max an Eqn.64 Ean. 68 e su scnpts L Eqn. 58 Eqn.61 . SJSv 0.559 0.607 0.688 0.592 ,R 0.831 0.796 0.736 0.813 ~Se(bo)/bo 0.365 0.755 0.373 0.046 LSe(b1)/b1 0.052 0.059 0.273 0.043 ~e(b2)/b2 0.135 0.266 L t1 0.831 0.796 0.312 1.714 L 12 0.631 0.275 bias 0.000 -0.021 0.000 -0.631 Graoh of residuals No pattern No pattern No pattern No pattern % of errors (#) > + 20% 27% (32) 32% (54) 25% (17) 90% (60) % of errors(#)>+ 40% 6% (7) ll% (19) 10% (7) 66% (44) % of errors(#)>+ 100% 0% (1) 2% (4) ' 1 % (1) 27% (18) The slope coefficients related to Vo,- in all four equations are positive, indicating that when the v 02 """ increases, the AT will increase also. Th us, the sign of these slope coefficients is rational. The slope coefficients for weight in the two 149 multiple regression equations are negative, indicating that when weight increases, the AT or the V 02max-AT difference decrease. When weight increases due to an increase in body fat, a subject may not be as fit. The AT occurs at higher values for fitter individuals (Claiborne, 1984). However, increased weight may occur when lean muscle mass increases through training. So, the rationality of the sign of the slope coefficients for weight is hard to assess. When the standard error of the regression coefficient (lines 3-5 in Table 10) is greater than 0.3 to 0.4, McCuen (1993) has found from experience that the coefficient is of questionable accuracy. Therefore, the intercept coefficients (line 3) in both equations 58 and 64 are of borderline questionable accuracy. The intercept coefficient in equation 61 is inaccurate, while the intercept coefficient in equation 68 is accurate. The slope coefficients (lines 4-5) are all less than 0.3 and are thus accurate. A partial regression coefficient (lines 6 and 7) close to one indicates an important predictor, while a coefficient near zero indicates an unimportant predictor. Thus, maximal oxygen consumption was an important predictor of AT in both linear equations (line 6). The partial regression coefficients for equation 64 indicated that Weight was not as important a predictor as maximal oxygen consumption but that both variables were important. Equation 68 has a partial regression coefficient greater than one (line 6). This meant that there were significant intercorrelations between the predictors. It is recommended (McCuen, 1993) that such a model not be used. 150 I For standard error ratios less than one, the model provides an improvement overp d ' · re 1ct10ns made with the mean. The standard error ratios for the four equations indicated that prediction accuracy could be improved by using the models in equations 58! 61, 64, and 68. The bias of a model should be close to zero. A positive bias indicates that a model consistently overpredicts, while a negative bias shows underprediction. Equations 58 and ofhave zero biases while equations 61 and 68 have negative biases. The plots of the residuals against the independent variables showed that there Were no patterns to the residuals (see Appendix B, Figures 72 to 77). This indicated a constant variance. The number and percent of errors greater than ± 20%, ± 40%, and ± 100% show that the errors produced by equation 68 are quite large. Ninety-percent of the predictions are in error by more than 20%. The other three equations have similar percentages of errors greater than 20%, 40%, and 100%. The model in equation 61 was eliminated because of the inaccurate intercept coefficient and the model bias. Due to model bias and large percent errors in prediction, equation 68 was eliminated also. The models in equations 58 and 64 have intercept coefficients that are of borderline questionable accuracy, zero biases, and similar percent errors in prediction. However, based on the standard error ratio, equation 58 provided a larger improvement in prediction accuracy over the standard deviation (0.559) compared to equation 64 (0.688). Therefore, equation 58 was selected. The anaerobic threshold was related to the maximal oxygen consumption by: 151 AT== 0.8624V02rnax - 7.1585 (58) where: AT, anaerobic threshold, mIJkg/min V 02max, maximal oxygen consumption, mIJkg/min A plot of the data and equation 58 are shown in Figure 12. Anaerobic threshold data was obtained for subjects who completed a study on th e effects of exhalation resistance in a respirator on performance of the wearer (Caretti et al., 2001). Additional data was obtained from Powers et al. (1984). Figure 13 shows this data overlayed onto a plot of equation 58 and the data used to obtain it. The new data is consistent with the data used to develop the equation. Equation 58 consistently overpredicts the anaerobic threshold for Caretti et al. (2001) and underpredicts for most of the Powers et al. (1984) data. The percent error in the residuals for the Caretti et al. (2001) data ranged from -29 to 9% while that for Powers et al. (1984) ranged from -6 to 67%. For the two validation studies combined, 38% of the errors are greater than 20%, 17% are greater than 40%, and 0% are greater than 100%. These prediction errors are higher than those for the original data used to develop equation 58. However, this does show that 83% of the predicted values are within 40% of the actual values. Considering the correlation coefficient of equation 58, the coefficient with the borderline questionable value, and the highly scattered data, these errors are reasonable. 152 -U\ I.;.) 80 70 • • 60 '2 ·e till ~ 50 g '"O 0 ..c 40 "' ., ~ u :E 30 0 ..... ., (SI C: -< 20 10 • 0 0 10 20 30 40 50 60 70 80 90 Maximal Oxygen Consumption (ml/kg/min) Figure 12. Relative anaerobic threshold plotted against maximal oxygen consumption. Shown is the best fit line. ao~---------------------------------------, 70 - 60 -0 0 ..c 40 "' ., ~ <.> :E 30 e ., "' t: < • data o Exh. R. A. Powers et al. -Equation 10 -- - --~---- _.. ~ --- ------ ----- - - ---- ---- - --~ • .. • • \ • 0+--- --.------,.--- -...-------.---- ---,-----...-------.-------,----- 0 10 20 30 40 50 60 70 80 90 Maximal Oxygen Consumption (ml/kg/min) Figure 13. Validation data shown with the original data and the best fit line. An equation can be fit to the validation data and the slope and intercept of the equation compared to the slope and intercept equation obtained from calibration. Th ' ts was not done because of the small amount of data and the variability in that data. The high correlation coefficient shows that the model fit the data well over the whole range of subjects. But, looking at any individual point, there may be a large error. This error is due in part to the heterogeneity of the data. This heterogeneity is evident even when looking just at one gender, one training status, and one small age range. For instance, Powers et al. (1984) looked at thirteen trained males and found that the AT occurred at 41 to 74% of Vo2max· So, even when a relatively homogeneous group is considered, the AT data is heterogeneous. Multiple regression equations were evaluated because it seemed likely that AT may have depended on more than just the V 02max· Part of the scatter may have been due to this other factor or factors. However, these equations provided less accurate predictions than the linear equation selected. The correlation coefficient of 0.83 found in this study was consistent with the results from Dwyer and Bybee (1983) (r = 0.87), Rusko et al. (1980) (r = 0.61), Thorland et al. (1980) (r = 0.81), and Weltman and Katch (1979) (r = 0.81). The subjects used in the previous studies included females and males that were recreational athletes or highly trained athletes. The present study included subjects With training statuses from sedentary to highly trained. Thus the relationship between AT and Vo2max appears to hold regardless of training status. The inclusion of sedentary individuals in the present study allows the results to be applied to a broader range of subjects. Respirator wearers are probably not highly trained athletes, so the 155 inclusion of sedentary people, recreational athletes and highly trained athletes should make the equation more applicable to actual respirator wearers. As the AT has been shown to be unaffected by respirator wear (Johnson et al., 1995), equation 58 applies to both respirator wearers and unencumbered subjects. Minute Ventilation as a Function of Oxygen Consumption Based on predictions from equation 58, the eight subjects in this study had one stage above the anaerobic threshold. Typical curves are shown for subjects 214 and 231 in Figures 14 and 15. (For plots of the data for the other subjects, see Appendix B, Figures 78 to 83.) The selected curves were used because a linear relationship below the AT and an exponential relationship above the AT had been seen for Progressive exercise (Martin and Weil, 1979). So, these curves were used to see if the same relationships held for constant-rate exercise. With only one point above the anaerobic threshold, it was difficult to assess whether an exponential curve was the best fit. There were four data points below the anaerobic threshold. While the correlation coefficients were high, this is due in part to the small number of data points. By examining the line itself through the data points, the fit of the equation Was observed. For many of the subjects, it appeared that there was a curvilinear relationship below and above the anaerobic threshold. The linear curves fit to the data below the anaerobic threshold had slopes that ranged from 17.544 to 34.519 and intercepts that ranged from -21.34 to 2.56. The 156 90 80 70 ~ / ~ 0 ~ ~ .. - 20 10 0 \ 0 0.5 1.5 2 2.5 3 3.5 Oxygen Consumption (Lpm) Figure 14. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 214. - 4 4.5 ...... I.J\ 00 50 45 40 £ 35 5 ';' 30 .2 ;g 2 c 0 5 > 2 0 0 :5 C i 15 10 5 0 / 7 ~ ~ ~ ~ - 0 0.5 1.5 2 Oxygen Consumption (Umin) Figure 15. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 231. ~ 2.5 slopes for the exponential curves ranged from 0.29 to 1.04 while the intercepts ranged from 6.28 to 26.15. As the exponential curves were fit to two points, it was expected that there would be a lot of variability in the slope and intercept coefficients. However, the coefficients for the linear portion showed a lot of variability also. This variability is not surprising considering the variability in the data itself. For a y 02 of 3 Umin, subject 001 had a minute ventilation around 64 Umin while subject 145 had a minute ventilation of 105 Umin. If V 02 were expressed as % V 02max, there was still a lot of variability. At 80-85% of Vo2max, subject 001 had a minute ventilation of 92 Umin while subject 002 had a minute ventilation of 38 Umin. Clearly, predicting minute ventilation from oxygen consumption alone would not give good results. So, the problem was the data seemed to yield similar shaped curves, but the slope and intercept coefficients were vastly different. As % V 02max is used to make comparisons among different subjects, it was decided to evaluate whether a % V Emax would be beneficial to make comparisons. So, the VEmax was obtained from each subject's V 02max test. (See Appendix B, Figures 84 to 91 for plots of the data.) The data were now all on a relative scale and were thus combined. Figure 16 shows a plot of the data. Because the relationship between the variables was unknown, linear (y =ax+ b), quadratic (y = ax2 +bx+ c), exponential (y == aeb), and power (y:: axb) models were fit to the data. The statistics for the four models are shown in Table 12. 159 ...... °' 0 90 80 •• • • • • • • • ··~ • • ~ ··~ • 30 • .. • •• ... • • 20 ••• 10 0 0 10 20 30 40 50 60 70 80 90 Percent of Maximum Oxygen Consumption (%) Figure 16. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for all subjects combined. 100 Table 12. St d d line an ar error ratio, bias, mean bias, and correlation coefficient for the ar, Quadratic, exponential, and power models. Linear Quadratic Exponential Power - SJSy 0.342 0.133 0.311 0.343 - Bias -0.001 0.147 -0.263 -0.511 - Mean bias 0 0.004 -0.006 -0.013 ~ R 0.941 0.951 0.966 0.959 L I I : The correlation coefficient for each model was high. The standard error ratios for the four models indicated that each provided a significant improvement over predictions made with the mean. Each of the models had a bias. The quadratic equation over-predicted (positive bias) while the linear, exponential .and power models under-predicted (negative bias). A model should generaIIy not be used beyond the range over which it was developed. However, no data was collected at work rates higher than 80-85% of V 02max, The overaII model that is being developed to predict the pulmonary effects of respirator wear during physical activity wi11 include higher work rates. The predicted % V Emax was detemuned for 100% V 02max to evaluate the applicability of the three models to higher work rates. The %VEmax for the linear, quadratic, exponential, and power models were 83.5%, 98.85%, 104.84%, and 81.66%, respectively. The linear and power models do not come close to predicting I00%VEmax for I00%Vo2max, while the exponential and quadratic models do. The linear and power models were rejected because of this. 161 The quadratic model had a lower standard error ratio and a smaller bias. The exponential model had a higher correlation coefficient and a lower average percent error (0.73% compared to 1.71%). However, the values for each of the statistics were close. There was no clear distinction between the quadratic and exponential models. The quadratic model was selected because of the slightly better statistics. The % V Emax was predicted from the following equation: %V£max =0.0095·%V 20 2 max -O.l33·%V02max +17.153 (69) A plot of the data and the regression curve are shown in Figure 17. (See Appendix B, Figures 92 to 94 for plots of the linear, exponential, and power models.) The data from the two validation subjects are plotted on a graph of equation 69 shown in Figure 18. The percent errors ranged from -22% to -3%. For these two subjects, the residuals (see Appendix B, Figure 95) and the percent errors showed that th e model consistently under-predicted the %VEmax· However, these errors were not large considering the variability of the data. 162 -0\ w 90 •• 80 • [ 70 i:: .9 ~ 60 i:: cu > cu :5 50 i:: ~ e 40 ::, e -~ ':2. 30 ._ 0 i:: cu • u 20 .... ~ 10 +-------------------------- ---------- ------ - - -------4 0+------,--------,-----------,------.------....------,~----,------,------l 0 10 20 30 40 50 60 70 80 90 Percent of Maximum Oxygen Consumption (%) Figure 17. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for all subjects combined. Shown is the best-fit quadratic model. 100 ,_. ~ 120 ~----------------------------------------------, ~ 100 C 0 -~ ·-·-·---- ------------------- c 80 - -- > ., :i C ~ E ::s E -~ ~ ..... 0 c ., ~ ~ 60 --equation 40 --- • 224 l:,,. 230 20 0+----------- ----...-- ------.----------,----------- -----1 0 20 40 60 80 100 120 Percent of Maximum Oxygen Consumption(%) Figure 18. Validation data from two subjects plotted against the quadratic model relating percent of maximum minute ventilation to percent of maximum oxygen consumption. Determining VEma.r· Equation 69 related the percent of maximum minute ventilation to the percent of maximum oxygen consumption. Maximum oxygen consumption is detennined from a common test and is reported in the literature. If th e required oxygen consumption is determined using equation 55, then the right- hand side of equation 69 can be determined by dividing the required oxygen consumption by the maximum oxygen consumption. The percent of maximum minute ventilation can be obtained from equation 69. In order to detennine the minute ventilation, the maximum minute ventilation is required. This can be obtained during the same test used to determine the maximum oxygen consumption. However , it is not reported commonly. A way of determining the maximum minute ventilation Was needed. The maximum minute ventilation (VEmax) was obtained for the subjects in the current study and a regression perfonned (see Appendix B, Figure 96). The high correlation coefficient (0.898) indicated that there was a strong relationship between the V d V Emax an 02max. Data were obtained from studies conducted by Johnson et al. (1999) and Caretti et al. (2001). The data were sorted in ascending order by V02max and then every third data point was removed and set aside for validation. The calibration data are shown in Figure 19. The regression equation was: VEmax = 20.01 v02max + 27.855 (70) ·1 · Umin where· V maximum minute vent1 at10n, · Emax, V 02max, maximum oxygen consumption, Umin 165 ...... °' °' 140 • • 120 ,-.. C ·-e ~ 100 .._,, = 0 ·:::: ~ 80 ~ > s ::I 60 C i e ::I 40 e ·s ';; 20 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 Maximum Oxygen Consumption (I.Jmin) Figure 19. Calibration data for maximum minute ventilation versus maximum oxygen consumption. Shown is the best fit line. 5 The correlation coefficient (0.751) was lower than that obtained from the current study (0.898). This showed that small data sets should not be used to fit physiological data due to the large variability in the data. The ratio of the standard error to the standard deviation (SJSy) was 0.678, Which indicated that the model provided an improvement over the mean in making predictions. The ratio of the standard error to the coefficient (Se(bi)/bi) for the slope a nd intercept coefficient were 0.207 and 0.467, respectively. McCuen (1993) has found that when the ratio is greater than 0.3 to 0.4, the coefficient is of questionable accuracy. The partial regression coefficient (t1) was 0.751, which indicated that the slope coefficient was a strong predictor. The model bias and mean bias were --0.001 and -1.4E-5. These low values showed that the model made slightly biased predictions. However, the bias was very small. There was no pattern to the residuals (see Appendix B, Figure 97). The validation data and the linear regression line were shown in Figure 20. The regression equation was: VEmax = 20.476V02max +33.396 (71) The Correl t· ff' . 0 823 The calculated t-values for the slope and .,. a 10n coe 1c1ent was . · intercept coefficients were 0.357 and 0.332, respectively. The null hypothesis was accepted for both coefficients. That is, the slope and intercept coefficients from the calibration and validation data were not statistically different. 167 -°' 00 160 140 ---C 120 ·e ~ C .s 100 ~ c II) > BO ~ :l C 'i • E 60 :l E ·Q_ «I 40 ~ 0+----------.--------..-----------.--------..----------,-------- 0 2 3 4 5 Maximum Oxygen Consumption (Umin) Figure 20. Validation data for maximum minute ventilation versus maximum oxygen consumption . Shown is the best fit line. 6 All statistics for the calibration equation (equation 70) except for the standard error ratio of the intercept coefficient (0.467) indicated that it provided accurate predictions of VEmax from V02max· McCuen (1993) has found from experience that a coeff · ICJent had questionable accuracy when the standard error ratio for a coefficient Was greater than 0.3 to 0.4. While the intercept coefficient was of questionable accuracy, it was statistically the same as the intercept coefficient from the validation equation. The fact that the model provided an improvement over the mean (SJSy < l .O), the slope coefficient was an important predictor, the model was unbiased, and there was no pattern to the residuals indicated that overall, equation 70 provided accurate predictions. An equation was obtained relating percent of maximum minute ventilation to percent of maximum oxygen consumption. While it is important to know that the minute ventilation versus oxygen consumption curve is linear below the AT and exponential above the AT, that relationship does not help in making predictions of minute ventilation for a given oxygen consumption. This is because two subjects are likely to have very different minute ventilations for the same oxygen consumption. This is true whether the oxygen consumption is expressed in Umin, ml/kg/min, or % V 0 2max. Thus a way to relate an individual's minute ventilation to his or her oxygen consumption was obtained by finding% VEmax as a function of% V 02max· In order to use equation 69, a way ofrelating VEmax to V02max was required. This was accomplished by relating the maximum VE recorded during a V 02max test to the V 02max· A good fit was obtained. 169 It had been mentioned that large data sets should be used when fitting empirical curves to physiological data due to the large variability in the data. Only eight subjects were used to fit equation 70. However, there was no additional data available. A search of the literature showed no one else who had presented the relationship between minute ventilation and oxygen consumption in the same way. In 0rder to have included more subjects, the VEmax was required. It is not common to report this variable. For instances where Vo2 and VE data would be reported, such as in graduate theses where different V 02 max tests were compared, no additional constant-rate exercise tests were performed. So, there were no additional data that could have been included. Equation 69 was developed over a work range of 25 - 85%. Work rates in the overall model will include work rates outside this range. Generally, a model should not be used outside the range over which it was developed (McCuen, 1993). However, as there were no additional data available, equation 69 was used for other Work rates. For this reason, one of the selection criteria was the % V Emax predicted by each equation for 100%Vozmax· Models that did not predict a %VEmax near 100% Were rejected. No other validation outside the 25-85% range was possible. Certainly, data should be obtained on more subjects over a broader range of work rates to detennine how well equation 69 makes predictions for a larger population. For now, this eq . .1 ble but this lack of data could limit the expected uat1on was the best one avm a , ac curacy of model results. 170 Tidal Vol F. · . ume as a unctzon of Oxygen Consumptwn The plots of steady state tidal volume versus steady state oxygen consumption are shown for two typical subjects in Figures 21 and 22 (see Appendix B, Figures 9B to 103 for the plots for the other subjects). The relationship between the variables for four of the subjects (023, 145, 173, and 214) was curvilinear. The other four subjects had different patterns. The plot for subject 001 showed that there might be a linear relationship up to a point where the tidal volume leveled off. This was the relationship reported by Martin and Weil (1979) for subjects undergoing incremental exercise. However, their subjects had linear curves up to the anaerobic threshold, With tidal volume plateauing above the anaerobic threshold. For subject 001 , the plateau appears before the anaerobic threshold. Martin and Weil (1979) did state that not all subjects exhibited the same pattern. The steady state tidal volume values were obtained when oxygen consumption reached a steady state. While minute ventilation was also at a steady state, tidal volume was often quite variable particularly at the lower work rates. At the higher Work rates, there was less variability in the 30-sec tidal volumes. These differences are probably due to the fact that the subjects had more willful control over their ventilation at the lower work rates than at the higher rates. The differences in the Patterns of tidal volume versus oxygen consumption are likely to be due to the non- steady state values of tidal volume for some of the subjects at the lower work rates. 171 --..l N 1.8 1.6 • • 1.4 1.2 • • 1 .8 0 .6 \ 0 .4 1 0 .2 0 \ 0 0.5 1.5 2 2.5 3 3.5 Oxygen Consumption (Umin) Figure 21. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 001. 4 1.4 1.2 1 ~ ., 0.8 e ::I 0 > ~ 0 f: ·\ OA \ 02 \ 0 • • • ... • 0 0.2 0.4 0.6 0.8 1.2 1.4 1.6 Oxygen Consumption (Umin) Figure 22. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 023. 1.8 The tidal volume at a given oxygen consumption varied by subject. A way of relating the tidal volume to oxygen consumption independent of the particular subject Was necessary, The maximum tidal volume was obtained for each subject. These Varied from 1.43 to 3.16 L. The %Vn,,,, and %Vo,""' were obtained. (See Appendix B p · ' igures 104 to 111 for plots of the data). At stage one, % V 02max ranged from 26- 3 1 % while % V Tmax ranged from 22-36%. So, there wasn't a lot of variability in %VT,,,., or %V02..,, at the low work rates. However, at stage five, there were large differences. For work rates of 77-86% of V 02=, tidal volume ranged from 61 -90%. So, even when the tidal volume was expressed relative to the maximum for each subject there was a lot of variability. The data from the subjects were pooled. A plot of the data is shown in Figure 2 3. From the plot, it appeared that there was a linear relationship between the Variables. However, the individual plots of% VTmax versus % V 02max for four subjects showed a curvilinear relationship. So, linear (y =ax+ b), quadratic (y = ax 2 +bx+ c), exponential (y = aeb), and power (y = axb) models were fit to the pooled data. A summary of the statistics is shown in Table 13. Table 13. Standard error ratio, bias, mean bias, and correlation coefficient for the linear, auadratic, exponential, and oower models fi~ to the % VTmax and % V 02max data. Linear Quadratic Exponential Power ,__ Se/Sy 0.425 0.402 0.446 0.427 --Bias 0.002 0.065 -0.797 -0.792 - Mean bias 3.52E-05 0.001 -0.015 -0.015 ,..__ R 0.9077 0.9077 0.8947 0.9030 ._____ 174 -...J VI 100 90 ~ 80 ~ u E ::s 70 0 > ca 60 • • "O ~ • • E so • • ::s E • -~ 40 ~ ._ 0 E 30 u u ... ~ 20 .... •• ~ . - • .... ~# • • • 10 0 0 10 20 30 40 so 60 Percent of Maximum Oxygen Consumption (%) Figure 23. Data pooled from the eight subjects who completed the current study. .... .... • • • • • • • • • • • • • 70 80 90 100 The standard error ratios indicated that all four models made improved predictions compared to predictions made with the mean. All four models had high correlation coefficients. The exponential and power model had biases of -0.8, indicating that they consistently under-predicted the % VTmax· The linear and quadratic models had small positive biases and thus over-predicted. The fact that the mean biases for the latter two models were near zero indicated that the model bias Was small compared to the average y-value (% VTmax), Because of their larger biases , the exponential and power models were eliminated. The linear and quadratic models had comparable statistics. For 100% Vo2max, the linear model predicted a tidal volume of 98% of maximum while the quadratic predicted 99% of maximum. The percent errors were evaluated. The total number of points greater than ± 20%, ± 40%, ± 50%, and± 60% were determined. Both models had 11 points greater than ± 20%, 3 points greater than ± 40%, 2 points greater than ±50%, and no points greater than ± 60%. As the statistics and percent errors were about the same for the linear and quadratic model, there were no statistical reasons for selecting one model over the other. The linear model was selected because it was simpler. The linear model was: %V = 0 9987-%V0, . -1.6809 Tm:ix • _max (72) A 1 · 1 · re shown in Figure 24. (See Appendix B, P ot of the data and the regresswn me a F . d · ponential and power models.) igures 112 to 114 for plots of the qua ratic, ex ' 176 100 90 • ~ 80 0 e 70 ::s 0 > -a 60 -0 l= e 50 ::s e -~ 40 ~ ..... 0 c 30 0 0 - ... -.l ~ 20 -.l 10 20 30 40 50 60 70 80 90 100 Percent of Maximum Oxygen Consumption(%) Figure 24. Linear model fit to the pooled data from the eight subjects who completed the current study. The plot of the validation data from subjects 224 and 230 is shown with a plot of the equation in Figure 25. For these two subjects, the model consistently under- predicted the % VTmax· The residuals showed that the errors were larger for lower % V 02max (see Appendix B, Figure 115). This did not agree with the residuals obtained with the original data set. The percent errors ranged from -42% to 0.2%. Seven of the ten data points were within± 20% error while nine of the ten were Within± 40%. These errors were comparable with those of the calibration data set. A larger data set is needed to truly validate equation 72. However, there are no other data available. Based on the limited data available, equation 72 makes adequate predictions of %VTmax as a function of %Vo2max· 178 ,....._ * ..._, 0 e ::I 0 > 120 100 -Equation • 224 80 --- + 230 0-1--------...--------~------~-- ------.--------------~ 0 20 40 60 80 Percent of Maximum Oxygen Consumption (%) Figure 25. Validation data from subjects 224 and 230 plotted with the linear model. 100 120 Maximum Tidal Volume as a Function of Maximum Oxy,uen Co . o nsumption. In order to use equation 72, the maximum tidal volume (VTmax) needed to be detennined. A h V s t e Emax was shown to be related linearly to Vozmax, it was possible that V l Tmax was re ated also to V 02max· The pooled VTmax and Vozmax data from the three studies were sorted in ascending order by V 02max so that the fuJJ range of v 02max values were used for both calibration and validation. A plot of the calibration data and the linear regression equation are shown in Figure 26. The equation was: VTmax = 0.3864 · V02rnax + 0.6416 (73) where: VTmax, maximum tidal volume, L V 02max, maximum oxygen consumption, L The standard error ratio was O. 769, which indicated that an improvement in the prediction accuracy was obtained with equation 73 compared with predictions made with the mean. The correlation coefficient was 0.664. The standard error ratios for the slope and intercept coefficients were 0.266 and 0.502, respectively. McCuen (1993) had found from experience that ratios higher than 0.3 to 0.4 indicated coefficients of questionable accuracy. So, the intercept may not be accurate. The partial regression coefficient for the slope (0.663) indicated that the slope coefficient was an important predictor. The bias and mean bias were -7.4E-05 and -4.lE-05. As both were essentially zero, the model made unbiased predictions. The residuals had no apparent pattern (see Appendix B, Figure 116). 180 ,_. 00 ,_. 3.5 ~-------------------------------------------------, 3+------------------------- ~------------------- -----, • 3 2.5 +------------------ ----- -------- --------------------1 '-' 0 E ::) ~ 2+-------------------------------=--=---- -~---------------~ «i -0 ~ E 1.5 +----------------------c.--=~------c--- ------------------ - ---------1 ::) E ">< ~ • • ~ 1~--------------------------------------- - - - - - - --t 0.5 -t------------ ------ - - -------- - ----- - - - --------- - ----l 0+----------------~-------~-------~-------~---------1 0 2 3 Maximum Oxygen Consumption (Umin) Figure 26. Linear equation fit to the calibration data. 4 5 6 The validation data d h 1· . an t e mear regression equation are shown in Figure 27. The equation is: V 0 2max = 0.5 · VTmax + 0.3879 (74) The correlation ff. · . coe icient for this equation was 0.816. The calculated t-values for th e slope and intercept coefficients were 0.662 and -0.575, respectively. As both were wi thin the critical value of± 2.306, the null hypothesis was accepted for both. That is, the slope and intercept coefficients from equations 73 and 74 for the calibration and validation data were the same. Summary of Tidal Volume as a Function of Oxygen Consumption. Tidal volume as a function of oxygen consumption for incremental exercise was shown for some subjects to increase linearly below the anaerobic threshold and plateau above the anaerobic threshold (Martin and Weil, 1979). Data plots for the subjects in this study showed that this relationship did not hold for steady state exercise. Four subjects exhibited curvilinear relationships while the other four each had different relationships. Part of the difference may be due to the fact that a steady state tidal volume was not always reached at low work rates even though oxygen consumption and minute ventilation were steady. Subjects were instructed to maintain breathing, stride, and arm movement as constantly as possible at the low work rates. However, many subjects reported that they would breathe shallowly and then take a deep breath. The overall minute ventilation did not change much, but the tidal volume did. This 182 3.5 • 3 ,,...__ d 2.5 0 e ::) 0 2 > -; -0 i= e 1.5 ::) e ">< ~ 1 ~ • ...... 00 w 0.5 0 0 1 2 3 4 5 6 Maximum Oxygen Consumption (Umin) Figure 27 Linear equation fit to the validation data. was seen in the data as a ]ow tida] volume often fo11owed a high tida] volume and vice-versa. At the higher work rates, subjects reported that there was Jess wi11fu] control of their breathing. This was evidenced by a more constant tida] volume. Wassennan et a1. (1980) showed that for Jong-term constant rate exercise the tida] volume would decrease slightly with time. The subjects in the current study showed variable responses with time. Some subjects had tida] volumes that decreased with time while others increased with time, varied throughout, or were near constant throughout. So, whi]e a steady state was not achieved, the average of the tida] volumes during the time period when oxygen consumption was at steady state was used as the steady state tidal volume. The fact that there was not a true steady state likely contributed to the differences between the shapes of the relationships. But as there was no common pattern to the tida] volume response with time across subjects and work rates, there Were no other options for obtaining steady state tida] volume from the data. Even though a curvilinear relationship was seen for four of the subjects, the best equation for the pooled data was a linear curve. While the quadratic equation did provide a comparable fit, it was rejected in favor of the simpler linear equation. The other two curviJinear functions, the exponential and power, gave biased predictions and were rejected. Overall, equation 72 made reasonable predictions. The relationship between VTmax and Vo2max was not as strong as that between VEmax and y 02max· Even with the weaker relationship, equation 74 predicted VTmax with reasonable errors. While the intercept coefficient was of questionable accuracy, the rest of the statistics indicated that equation 74 made reasonable predictions. The 184 validation equation was statistical1y the same as the calibration equation. The fact that the correlation coefficient was higher for the validation equation than for the calibration equation is another example of why smal1 data sets should not be used with physiological data. The Effects of Resistance on Minute Ventilation and Tidal Volume The multiple regression equations relating minute ventilation to inhalation and exhalation resistance for each of the five stages were: Stage one: VE =0.3705-0.0037Rinh -0.02236Rexh (75) Stage two: VE = 0.4754-0.00I8R;nh -0.0206Rexh (76) Stage three: VE = 0.6088-0.0065Rinh -0.0469Rexh (77) Stage four: VE =0.9718-0.0156Rinh -0.0846Rexh (78) Stage five: VE= 1.3979-0.0454Rinh -0.0967Rexh (79) where: VE, minute ventilation, Us Rinh, inhalation resistance, cmH20/Us R h exhalation resistance, cmH20!Us ex, The equations for tidal volume were: Stage one: V = 0.5023 + 0.0059R inh + 0.1046Rexh T (80) 185 Stage two: VT= 0.6271 +0.0092Rinh +0.2080Rexh Stage three: VT = 0.9698 - 0.009 lRinh + 0.0890Rexh Stage four: VT = l.4525-0.0027Rinh -0.0024Rcxh Stage five: VT = l.7955-0.0162Rinh + 0.0746R exh where: VT, tidal volume, L Rinh, inhalation resistance, cmH20/Us Rexh, exhalation resistance, cmH20/Us (81) (82) (83) (84) Plots of the intercept and slope coefficients versus work rate for the minute ventilation and tidal volume equations are shown in Figures 28 to 31. The minute ventilation increases curvilinearly. This is to be expected from equation 69 relating minute ventilation to oxygen consumption. Similarly, the increase in tidal volume with work rate is linear as was shown in equation 72 relating tidal volume to oxygen consumption. Figure 29 shows that the resistance coefficients for minute ventilation related to work rate have a greater magnitude as work rate increases, with the exhalation resistance coefficient always having a greater magnitude than the inhalation resistance coefficient. The resistance coefficients for tidal volume shown in Figure 31 do not have a definite pattern. The standard error ratio and correlation coefficient for the regression of minute ventilation or tidal volume on inhalation and exhalation resistance separately are shown for each of the five stages in Table 14. The bias for each model was approximately zero. 186 ...... 00 -.l 1.6 1.4 -.... 1.2 • 8 . 6 ... • 0 . 4 • 0.2 0 I 0 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 28. The intercept coefficients across work rates for the equations relating change in minute ventilation to inhalation and exhalation resistance. 90 -00 00 0 I 10 20 -0.02 - ---- -- -- ~----- · 6 1 -0.04 - ----- u ..:;-- M~ c -~ -0.0 IE '8 u ., u 6 B -o. -~ 08 ! -0.1 0.12 I I • Inhalation a Exhalation • 30 • 70 80 ~b 40 • 50 60 • D --------------- 0 • 0 0 Percent of Maximum Oxygen Consumption (%) Figure 29. The resistance slope coefficients across work rates for the equations relating change in minute ventilation to inhalation and exhalation resistance. -00 \0 2 1.8 . ... 1.6 ~ 1.4 • ii ~ 1.2 B ..5 ... 5 • ::, 0 > 0.8 :a l= 0.6 • • 0.4 0.2 0 0 10 20 30 40 50 60 70 80 90 Percent of Maximum Oxygen Consumption (%) Figure 30. The intercept coefficients across work rates for the equations relating change in tidal volume to inhalation and exhalation resistance. -\0 0 0.25 0.2 6 ~ 0.15 1 = "' ·n o. 1 <:: 8 u "' g ~ 0.0 -~ "' °' ~~~- • Inhalation o Exhalation 5 0 10 0.05 I D - D D D • • .. 20 30 40 • 50 60 70 80 • Percent of Maximum Oxygen Consumption (%) Figure 31. The resistance slope coefficients across work rates for the equations relating change in tidal volume to inhalation and exhalation resistance. ~b -Tabl_e 1~. Standard error ratio and correlation coefficient for steady-state mi ventilation and tidal volume regressed on inhalation and exhalation resistancn~te each of th t e 1or es ages. ~ Minute Ventilation SefSv R Stage 1 0.26 0.966 Stage 2 0.12 0.993 ~ Stage 3 0.35 0.937 Stage 4 0.38 0.925 ~ Stage 5 0.43 0.903 Tidal Volume Stage 1 0.89 0.456 Stage 2 0.24 0.971 ~ Stage 3 0.94 0.341 Stage 4 0.89 0.456 Stage 5 0.02 0.9998 The standard error ratio provided an indication of the improvement in predictions made with the model compared to predictions made with the mean. A value close to one indicated that the model did not improve prediction accuracy. There were four respirator conditions and three variables being fit. With a low number of degrees of freedom, it would be expected that the correlation coefficient would be close to one. The power of the regression equations was determined. The null hypothesis was that the correlation coefficient was zero. A standard error ratio less than o. 7 would show that a significant improvement in prediction accuracy had occurred (Mccuen, 1993). The correlation coefficient corresponding to a standard error ratio of 0.7 was 0.71 (from the relationship Se2 = sy2 (l-R2)). Thus, the alternative hypothesis was that the correlation coefficient was greater than 0.71. For a =0.05 and 8 subjects (n = 8), the power was 0.63. As the power equals 1 - B, B (the probability of a type two error) was 0.37. This means that the null hypothesis would be accepted 191 - - - 37% of the time when it is false. In other words, the regression is considered not significant 37% of the time when it really is. The standard error ratios were low and correlation coefficients were high for th e minute ventilation equations. These statistics indicated that there was a strong relationship between minute ventilation and resistance and that the equations provided improvements in prediction accuracy over predictions made with the means. For the tidal volume equations, the standard errors were high and the correlation coefficients low for stages one, three, and four. These statistics indicated that the equations relating tidal volume to resistance at stages one, three, and four were not accurate. The equations for stages two and five had low standard error ratios and high correlation coefficients. Thus, equations 81 and 84 provided good predictions of tidal volume. All of the slope coefficients in the minute ventilation equations were negative, indicating that minute ventilation decreased with increased resistance. These results agreed with those reported in the literature (Flook and Kelman, 1973; Si1vennan et al., 1951; Hermansen et al., 1972; CerretelJi et al., 1969; Caretti and Whitley, 1998; Johnson et al., 1999; Caretti et al., 2001). Flook and Kelman (1973) found that the slope coefficients for inhalation resistance for work rates of 35, 50, and 70% were - 0.0023, -0.005, and -0.214, respectively. These work rates corresponded with stages two, three, and four in the current study. The slope coefficients in the current study (- 0.00 l 8, -0.0065, and-0.0156) were of the same order of magnitude as those found by Flook and Kelman (1973). Johnson et al. (1999) reported an inhalation slope coefficient of-0.0687 for work at 80- 85% of Vo2max· The slope coefficient of 192 inhalation from stage five in the current study was -0.0454, which is of the same magnitude. For exhalation resistance, Caretti et al. (2001) found that for work done at 80 - 85% of V 02max the slope coefficient was -0.0299. The corresponding slope coefficient from the current study was -0.09674, three times that found by Caretti et al. (2001). Caretti et al. (2001) found that the ratio of the slope coefficients of inhalation resistance to exhalation resistance was approximately three. In the current study, the exhalation resistance coefficient always had a higher value than the inhalation resistance. The ratios of exhalation to inhalation coefficients for the five stages were 6, 11, 7, 5, and 2. While Silverman et al. (1951) investigated the effects of inhalation and exhalation on minute ventilation at high work rates, the equations were not reported. So, magnitude comparisons cannot be made with this study. The reason for the discrepancy between the relative effects of inhalation and exhalation resistance is unknown. However, a small range of exhalation resistances (0.8 to 1.69 cmHzO/LJs) was used in the current study. Caretti et al. (2001) used a wider range of resistances (0.27 to 27 .35 cmHzO/I.ls). Perhaps the true effects of the exhalation resistance were not obtained with the current study. Flook and Kelman (1973) investigated the effects of inhalation resistance on tidal volume. The authors reported that the slope coefficients of inhalation resistance were 0.0078, 0.0011, and 0.009 for exercise performed at 35, 50, and 70% of Vozmax, Only the first slope was significant, so there was no effect of inhalation resistance on tidal volume at work rates of 50 and 70% Vo2max· The inhalation resistance slope coefficient from the second stage of the current study (35 - 40% V 02max) was 0.0092, 193 which was of the same order of magnitude as the Flook and Kelman (1973) coefficient. The coefficients of inhalation and exhalation resistance for stage two Were both positive, which indicated that tidal volume increased with increasing resistance. This agreed with the results of Silverman et al. (1951) and Hermansen et al. (1972) that tidal volume at low work rates increased with resistance. There were little data on the effects of resistance on tidal volume at very low work rates. The equation for stage one of the current study was rejected because of the high standard error ratio. Silverman et al. (1951) found for subjects pedaling a bicycle ergometer with no load that tidal volume increased with resistance. This would appear to conflict with the current study that there was no effect of resistance on tidal volume at the lowest work rate. The rejection of the stage one equation may be due to the fact that the power of the current study (0.63) was lower than the conventional value of 0.8 (Ewen, 1971). With a low power, the regression may be found insignificant despite the fact that it is significant. The fact that the equations for stage three (45-50% Vo2max) and four (65 _ 70% V 02max) in the current study did not provide accurate predictions indicated that there was not a significant effect ofresistance on tidal volume at these two stages. These results agree with those of Flook and Kelman (1973). Silverman et al. (1951) found also that there were only sma11 changes in tidal volume with resistance at moderate work rates. At high work rates, Hermansen et al. (1972) and Silverman et aJ. (1951) found that tidal volume decreased with increased resistance. Caretti and Whitley (1998) found that tidal volume was insensitive to resistance at 80 - 85% V 02max- However, 194 the external work rate was adjusted for each respirator conditions so that the subject was working at 80 - 85% V 02max with each respirator. Assuming the subjects were able to continue to increase their tidal volumes with the increased external work rates the effect of resistance may not have been seen. Tidal volume may have increased, but the increased resistance could have offset the tidal volume increases. The slope coefficient of the exhalation resistance for stage five was positive, indicating that the exhalation resistance increased the tidal volume. While both Silverman et al. (1951) and Hermansen et al. (1972) found that tidal volume decreased at high work rates, the individual contributions of inhalation and exhalation resistance were not quantified. For stage five in the current study, the percent changes in tidal volume compared to the lowest condition were 3.5, 2.6, and -3.5%. So, the tidal volume increased and decreased. If the percent changes were instead compared to the first respirator condition, the changes were -1 and -7%. Both Silverman et al. (1951) and Hermansen et al. (1972) used only two resistances. As the effects of resistance on tidal volume in the current study depended on which resistances were compared, perhaps the true effect of resistance on tidal volume was not seen in the other two studies. Change in Minute Ventilation with Dead Space The minute ventilation and dead volume data are presented in Table 15. The dead volumes shown in the table differ from the actual values used by Stannard and 195 , Russ (1948) because the table values were read off their Figure 1, a plot of data points showing change in minute ventilation versus dead volume. Table 15. Changes in minute ventilation (Us) with external dead volume (L) at rest and during light and heavy exercise. The rest and light exercise data are from Stannard and Russ (1948) while the 80- 85% Vo2max data are from Johnson et al. (2000) _ . Vo /J.VE Exercise Level (L) (Us) , 0.249 0.0348 Rest ,_0.351 0.0546 Rest 0.351 0.0565 Rest j),419 0.0621 Rest 0.543 0.0800 Rest 0.645 0.1073 Rest 0.249 0.0019 Light Exercise 0.351 0.0169 Light Exercise 0.419 0.0358 Light Exercise 0.543 0.0621 Light Exercise 0.645 0.0753 Light Exercise 0.288 0 80 - 85% Vo2max 0.381 0 80 - 85% Vo2max 0.445 0 80 - 85% Vo2max 0.645 0 80 - 85% Vo2max 1.162 0 80 - 85% Vo2max Figure 32 shows a plot of the resting data and the regression line. The equation that resulted from the regression was: (85) /J.VE = 0.170432V0 -0.00681 where: Vo, added external dead volume, L 6. VE, change in minute ventilation, Us 196 0.12 -r--------- --------------- ------ --------- • 0.1 -t------- ------------------------ --~-=---------1 ~ ~ 0.08 -t------------------------- - ------,;;;;o.,C..~~--------1 0 § 'E ~ 0.06 1-- ------------ - --- - --- ,,,,;l-~~----- --------- --1 (I) :5 C ~ .$ 0.04 ;-- -- --------- - - __,,,,,l!C:._ _ _ _ _ ___ ___ ________ _ _ __ --l Q) -0 0.02 ;------- ------ --- - - - --- - - ------- - - - - - ---1 0-t---------.--------.------..-------,--- - - --r------.....- ---~ 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Dead Volume (L) Figure 32. The change in minute ventilation with added dead volume for resting subjects. The correlation coefficient was 0.984, which indicated there was a strong correlation between the change in minute ventilation and the dead volume. The model predictions were much better than predictions made with the mean as evidenced by the standard error ratio of 0.17. The bias and mean bias were both zero so the model did not consistently over- or under-predict. There was no pattern to the residuals (see Appendix B, Figure 117). The percent errors ranged from -6% to 7%. Thus, equation 85 accurately predicted the change in minute ventilation due to added dead space for resting subjects. The plot of the light exercise data and the regression line are shown in Figure 33. The relationship between the change in minute ventilation and the dead space was: dVE = 0.19414V0 -0.04733 (86) A correlation coefficient of 0.9944 indicated that there was a strong relationship between the variables. The standard error of 0.12 showed that the model predictions were an improvement over predictions made with the mean. The bias and mean bias of zero indicated that the model neither consistently over- nor under-predicted. There was no pattern to the residuals (see Appendix B, Figure 118). The percentage errors were -45%, 23%, -5%, -6%, and 4%. Overall, the model made accurate predictions of the change in minute ventilation based on dead space for subjects performing light exercise. 198 - '° '° 0.09 -r------------ ---------- ----------------, 0.08 4-- --- ----------------------------------, _ 0.07 -1- --------------------------------~-- -----, :3 ~ 0.06 -1- -----------------------------~ --------------i .Q ~ 'E 0.05 --1--------------------------- - ~ '-----------------------j Q) > ~ 0.04 -1- -----------------------~'--------- -- -----------. ::J C: ~ ~ 0.03 Q) .:, 0.02 +-------------------~'----------------------------; 0.01 -t- -- - ----------------,..,_---------------------i 0 +- -----,-------,----=-----.-- ------,------,-------,,------; 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Dead Volume (L) Figure 33. The change in minute ventilation with added dead volume for lightly exercising subjects. Stannard and Russ (1948) noted that the slopes of the two equations were similar and that there appeared to be a 2 Umin or 0.033 Us difference between the corresponding minute ventilations. The t-test of the slope and intercept was used to test this observation statistically. The calculated t values for the slope and intercept Were 0.13 and -8.47, respectively while the critical t value was 3.182. So, the null hypothesis was accepted for the slope coefficient but not for the intercept coefficient. Thus, the slope coefficients of equations 85 and 86 were the same while the intercept coefficients were different. The average difference between the predictions made with equations 85 and 86 were 0.0301 Us, or 1.80 Umin, slightly less than the 2.0 Umin observed by Stannard and Russ (1948). The light exercise involved work rates that doubled the resting oxygen consumption. Actual data were not provided. If the resting oxygen consumption was assumed to be 0.45 Umin and the V 02max were 3 Umin, the resting oxygen consumption was 15% of Vo2max while the light exercise was 30% V 02max. These resting and maximal oxygen consumptions were typical values obtained from the current study. If it is further assumed that the minute ventilation decreases 1.8 Umin for every 15% increment in % V 02max, an equation can be developed that relates the change in minute ventilation to both dead volume and work intensity. The 1.8 Umin decrement could be subtracted from the original reSting equation. This would yield: (%V02 . -0.15) (1.8) L\VE =0.170432VD -0.0068l- ;~~5 . 60 (87) 200 The third term decrements the minute ventilation 1.8 Umin or 0.0301 Us (1.8/60) for every 15% increment in work intensity. For a work intensity of 15%, equation 87 reduces to equation 85. Equation 87 was applied to the light exercise data. The residuals indicated that the model over-predicted for low dead volumes and under-predicted for higher dead volumes (see Appendix B, Figure 119). With only five points, it was difficult to tell whether there was truly a pattern to the residuals. The percentage errors were 194, 35, -4, -10 and -3%. The 194% error occurred for the 0.249 L dead volume. The actual change in minute ventilation was very small, 0.0019 Us or 0.1129 Umin. The predicted value was 0.33 Umin, so the error is really just 0.22 Umin. So, equation 87 does make accurate predictions for light exercise. For heavy exercise, Johnson et al. (2000) reported no change in minute ventilation with external dead space. Equation 87 predicted negative changes in minute ventilation for work rates of 80% V02max· If the results were forced to zero, equation 87 would be accurate. For equations 85 and 86, change in minute ventilation were predicted for no added dead volume. The data on which these two equations were based only looked at dead volumes between 250 and 645 mL. Generally, models should not be used beyond the data ranges for which they were developed (McCuen, 1993). However, data were not available at lower dead volumes for subjects at rest or during light exercise. The overall model of the pulmonary effects of respirator wear will include a no mask condition, and hence a condition with no added dead volume. Equations 85 and 86 will be used for that model. If the equation predicts a negative minute 201 ventilation, the change in minute ventilation is forced to zero. What this says is that as work rate increases, a given dead volume causes a smaller change in minute ventilation. This agrees with the results obtained by Stannard and Russ (1948) for resting and lightly exercising subjects. Their Figure 1 and equation 86 showed that for lightly exercising subjects, dead volumes below approximately 250 mL would not change minute ventilation. If their graph, or equation 86, were extrapolated below 250 mL, negative changes would result. Forcing the change to zero simply says that the given dead space has no effect on minute ventilation at that work rate. So, predictions of the change in minute ventilation due to external dead space at different work rates could be determined using equation 87. If the equation predicted negative changes in minute ventilation, the change was forced to zero. The effects of dead volume on minute ventilation for subjects exercising at moderate work rates needs to be quantified. The literature had many articles on the effects of dead space, but there were problems with the reported results. Some researchers only reported subjective results (Shimozaki et al., 1988) or used subject- selected work rates (Harber et al., 1982) or only used one combination of resistance and dead space (Harber et al., 1984; Harber et al., 1988; Harber et al. , 1990), preventing comparisons from being made. Ward and Whipp (1980) did perform a study in which three subjects exercised with dead volumes of 0.1 to 1.0 L. Minute ventilation was reported versus absolute carbon dioxide production for one subject. The linear relationship between minute ventilation and carbon dioxide production shifted upwards and to the left for increases in dead volume. Data points were not recorded at the same v coz, so changes in minute ventilation could not be quantified. 202 Many assumptions were made in developing equation 87. Errors in predicting the change in minute ventilation at moderate intensity exercise were likely. The work intensity was assumed. It was assumed also that similar decreases in minute ventilation occurred as exercise intensity increased as was reported in Stannard and Russ (1948) for the rest and light intensity exercise. However, no additional data were available. More studies and more testing of equation 87 are needed. 203 Change in Tidal Volume with Dead Space The tidal volume and dead volume data are shown in Table 16. Table 16. Changes in tidal volume (L) with external dead volume (L) at rest and during light and heavy exercise. The rest and light exercise data are from Stannard and Russ ( 1948) while the 80 - 85% V o2max data are from Johnson et al. (2000). Vo (L) 0.25 0.35 0.35 0.42 0.55 0.640 0.25 0.35 0.42 0.55 0.640 0.288 0.381 0.445 0.645 1.162 !!,,.VT Exercise Level (L) 0.132 Rest 0.209 Rest 0.163 Rest 0.144 Rest 0.347 Rest 0.410 Rest 0.006 Light Exercise 0.111 Light Exercise 0.114 Light Exercise 0.310 Light Exercise 0.386 Light Exercise 0 80 - 85% V 02max 0 80 - 85% Vo2max 0 80- 85% Vo2max 0 80 - 85% V 02max 0 80 - 85% V 02max The equation obtained from regression on the resting data was: !!,,.VT =0.7468VD - 0.08445 where: V 0 , added external dead volume, L !!,,.VT, change in tidal volume, L (88) The data and the regression line are shown in Figure 34. The correlation coefficient was 0.9229, which indicated that there was a high correlation between the dead 204 N 0 Vl 0.45 0.4 0.35 d 0.3 (I) E :J 0 0.25 > ~ "O 0 .2 i= .s -a; 0.1 "O 5 .1 0 0 .05 O' 0 0.1 • / / / • / /. •/ • 0.2 0.3 0.4 0.5 0.6 Dead Volume (L) Figure 34. The change in tidal volume with added dead volume for resting subjects. 0.7 volume and the change in resting tidal volume. The model and relative bias were zero, indicating that the model neither consistently under- or over-predicted. The st andard error ratio of 0.43 indicated that equation 88 made better predictions of tidal Volume than the mean tidal volume. There might be a pattern to the residuals (see Appendix B, Figure 120). The model may under-predict for low and high values of dead volume and may over-predict for moderate values. However, at a dead volume of 0.35 L, the model over-predicts one point and under-predicts the other. With only six data points, a pattern to the residuals was difficult to detect. The percentage error ranged from -23% to 59%. Four of the points were within± 20%. The statistics indicated that equation 88 made adequate predictions of the change in tidal volume with dead volume for resting subjects. However, due to the variability seen in physiological data, any equation obtained from only six data points should be used With caution. For light exercise, the relationship between the change in tidal volume and dead volume was: .1 VT = 0.9933VD -0.2537 (89) F. 35 h h d d eg"ession line The correlation coefficient of 0.9837 1gure s owed t e ata an r •· · · d ' t ng relationship between tidal volume and dead in 1cated that there was a very s ro . h · tently over- nor under-predicted as indicated by the volume. The model ne1t er cons1s . . Th tandard error ratio was 0.2076. This indicated zero model and relat1 ve biases. e s b edictions of the change in tidal volume that equation 89 made much etter Pfi 206 N 0 -.l 0.45 -------------------------------------------, 0.4 .J__ _____ ____________________ _ _ ________ /-----------1 0.35 .J__ ____________________ _ _____________ __,,,_~-----1 ./ _ 0.3 +--- -------------------------- ---/-____,._,,~---------I :::!.. Q) § 0.25 +--------------- --- ----------- -/------------- -------1 0 / > 0.2 +- -----------------------/ __ _.,,_ _____________ --! m "O i-= 0.'\5 +----------------------------,,,,_--------------------1 s / l •/ • O.'\ -l-\----------/------=.,:....------------------1 0.05 1 / ... / 0 \ -0.05 -'---------------------------------------------' . O.'\ 0.2 0.3 0.4 0.5 0.6 07 Dead Volume (L) Figure 34. The change in tidal volume with added dead volume for lightly exercising subjects. compared to using the mean change in tidal volume. The residuals indicated that the model under-predicted the change in tidal volume with low and high dead volumes a nd over-predicted at moderate dead volumes (see Appendix B, Figure 121). Again, With only five data points, the actual pattern to the residuals was difficult to assess. The percent errors ranged from-189% to 43%. However, the point that generated the -lB9% error had a negative predicted tidal volume change. The actual value was 0.006 Land essentially represented no change in tidal volume with a dead volume of 0.25 L during light exercise. Three of the five points were within 15% of the actual values. The statistics indicated that the model made accurate predictions of the change in tidal volume with dead volume except at low dead volumes. If negative changes were predicted, the change was forced to be zero. Stannard and Russ (1948) reported that the exercise intensity was selected to double the resting oxygen consumption. Maximal oxygen consumption and resting oxygen consumption values were not reported. Assuming a resting oxygen consumption of 0.45 Umin, doubling the resting value would yield 0.9 Umin. The resting oxygen consumption expressed as % Vozmax would be 18% while the light exercise would be 36% assuming a V 02max of 2.5 Umin. If the V 02max were 3.0 Umin instead, the resting and light exercise would be 15% and 30% respectively. The resting and V o2max values were typical values from the current study. So, the resting and 11·ght . 1 .. Stannard and Russ (1948) were assumed to occur at exercise va ues 1rom 15% and 30% of Vo2max· . . .. ·t to the data in Table 16 was: The multiple regress10n equat10n JI 208 LlVT =0.1950+0.2517VD 0.4256%V02 max 100 (90) The correlation coefficient of 0. 79 indicated that there was a strong relationship between the change in tidal volume and dead volume and % Vozmax· The model and mean bias were zero which indicated that the model did not consistently over- or u nd er- predict. The standard error ratio was 0.6583. Thus, predictions made with the model were better than predictions made with the mean. There was no pattern to the residuals (see Appendix B, Figure 122). The percentage errors ranged from -64% to 40%. Thus, equation 90 made acceptable predictions of the change in tidal volume resulting from added dead volume. For high work rates and low dead volumes, the multiple regression equation predicted negative changes in tidal volume. This contrasted to the zero changes in tidal volume with dead volume found by Johnson et al. (2000) and Caretti and Whitley (1998) for work rates of 80-85% V 02max· This can be corrected with the multiple regression equation by setting all predicted negative changes to zero. For resting and lightly exercising subjects, equations 88 and 89 had small~r errors than equation 90, the multiple regression equation. For this reason, equations 88 and 89 Were used for predicting the changes in tidal volume with dead volume for resting or lightly exercising subjects (30% Vozmax), All predicted negative changes were forced to zero. Additionally, for a 0.25 L dead volume at 30% Vo2max, the change in tidal volume was close to zero. For all work rates greater than 30% Vo2max, the effect of dead volumes of 0.25 Lor smaller were assumed to be zero. It is possible that as 209 work intensity increases th f , e amount o dead space that does not affect tidal volume will increase. For example, it may be that at 50% V o2max, dead volumes of 0.3 Land lower have no effect on tidal volume. Because there were no data to support this contention, such an effect was not included in the model. There are a number of studies that have been conducted on the effects of dead volume at moderate intensity exercise, but these studies did not provide useful data for this model. Harber et al. (1982) had subjects working at moderate intensities and reported that the dead volume caused a decrease in tidal volume. However, subjects selected their own work rates so that the rate was consistent with long-term work. So, the effect can't be quantified because the subjects were not all working at the same absolute or relative work rate. Additionally, individual subject data was not reported. Other studies conducted by the same group of authors (Harber et al., 1988; Harber et al., 1984; Harber et al., 1990) looked at the effects of one load that consisted of an inhalation resistance and a dead volume. While adding dead space usually adds a resistance as well, including more conditions would have made comparisons possible. One study by these authors (Shimozaki et al., 1988) did look at combinations of inspiratory and expiratory loads and dead volume. Unfortunately, only subjective responses were reported. Ward and Whipp (1980) studied the effects of dead spaces of 0.1 to 1.0 L on three subjects during exercise. The effects of the dead space on tidal volume were not reported. More information on the effects of dead volume on tidal volume during light and moderate intensity exercise is needed. The multiple regression equation based on the Stannard and Russ (1948) data assumed work rates for the reported data. Clearly 210 th" is was not as accurate as using actual work rates, but these were not reported. Equation 90 is based on a number of assumptions and is likely to make errors in predictions. However, no other infonnation on the separate effect of dead volume on tidal volume was available to include in the calibration or to perform a validation. Oxygen Consumption as a Function of Minute Ventilation Regression usually assumes that there is no variability in the x-variable; alI the Variability is in the y-variable. Therefore, an equation obtained from regressing a dependent variable on an independent variable should not be used to solve for the independent variable unless the correlation coefficient equals one (McCuen, 1993). So, equation 69 (from minute ventilation as a function of oxygen consumption) could not be solved for oxygen consumption based on minute ventilation. The plot of the data and the regression line are shown in Figure 36. The equation of the line was: V 0 2 = 0.0340VE + 0.4322 (91) where: VE, minute ventilation, Umin y 0 2, oxygen consumption, Umin Th . ff. . t tandard error ratio of the model, standard error ratio of e correlat10n coe 1c1en , s h . ffi ·ents and the model bias were 0.928, 0.378, 0.065 and t e slope and mtercept coe 1c1 , ' 0.25 I' respectively. The correlation coefficient indicated that there was a very strong 211 N -N 4.5 ~--------------------------------------------, C .g 2.5 +-------------------------....~---------------------i 0.. E ::, § 2-1---- ------------__,,,r-c__ _________________ ________ ~ u C cu ~ 1.5 -l-- --- - -----------cli#-'.Y..---- ----------- - ---------------------1 X. 0 ••• 0.5 -1--------=-·-------------------------------------~ 0+-------~-------------~------~--------.--------l 0 20 40 60 80 100 Minute Ventilation (Umin) Figure 36. Oxygen consumption and minute ventilation from the levels determination session. Shown is the best fit line. 120 relationship between the two variables. The standard error ratio for the model was an indicator of the improvement in prediction accuracy for predictions made with the model compared to those made with the mean. The closer the number is to zero, the greater the improvement. So, a large improvement in prediction accuracy was achieved using the model. Standard error ratios of coefficients indicate the importance of that coefficient. Values close to zero indicated important predictors. Both the slope and intercept coefficients were important predictors. The model bias Was zero, which indicated that the model neither under- nor over-predicted consistently. There was no pattern to the residuals (see Appendix B, Figure 123). The percent errors ranged from -20% to 46% with 90% of the errors less than ± 30%. Eighty-seven percent of the errors were within± 25%. Overall, the statistics indicated that the model made accurate, unbiased predictions. The validation data are plotted in Figure 37. The percent errors ranged from_ 9 to 16% with 90% of the error within± 10%. These errors were smaller than those obtained with the calibration data. Oxygen Consumption as a Function of Tidal Volume Regression usually assumes that all of the variability is in the x-variable and none is in the y-variable. For this reason, equations developed by regressing yon x should not be used to solve for x unless the correlation coefficient is one (McCuen, 1993). Therefore, equation 67 (from tidal volume as a function of oxygen consumption) was not solved for the oxygen consumption. 213 4.5 ~------- --- ------ -------------------------, § ·g_ 2.5 -1---- ----- ---------- --- --=~,,.,,,::....---- -------------- ---i E ~ "' g 2-1---- - - - -------------~--- ----------------------4 u C cu ~ 1.5 -1---- --- ----- -....,,,.,,,,_::.__ ______ _________ ______________ 4 >( 0 0 .5 -1--- ------------- ------ ------- --- --------------l o+-- -------,--------~--------,---- - ----,------ -..---------1 0 20 40 60 80 100 Minute Ventilation (IJmin) Figure 37. Validation data plotted against the best fit line from regression of oxygen consumption against minute ventilation. 120 The data and the regression line are plotted in Figure 38. V02 = l.3851VT +0.2896 (92) where: Vy, tjdal volume, L V 02, oxygen consumption, Umin The correlation coefficient, standard error ratio of the model, and standard error ratios of the slope and intercept coefficients were 0.924, 0.388, 0.068, and 0.414, respectively. The high correlation coefficient indicated that there was a strong relationship between the two variables. The standard error ratio of the model indicates whether any improvement in prediction accuracy has occurred with the model. The ratio of 0.388 indicated that a large increase in prediction accuracy occurred. The st andard error ratios of the coefficients indicated the accuracy of the coefficients. Mccuen (1993) found from experience that values greater than 0.3 to 0.4 may indicate a coefficient of questionable accuracy. So, the slope coefficient was accurate, but the intercept coefficient may be of questionable accuracy. The model bias was zero, indicating that the model neither consistently over- nor under- predicted. There was not a pattern to the residuals (see Appendix B, 124). The percent errors ranged from - 31 % to 53% with 90% of the errors within± 30%. Eighty-seven Percent of the errors were within 25%. Figure 39 shows the validation data plotted with the regression line. The percent errors ranged from - 30% to 42%. Ninety percent of the errors were within ± 215 N -0\ 4.5 --.--- --------------------------------------, '2 ·a 3 -l- --------- ------ - ---_y_-------,.,,,,,,,.~,.---------- ---- --1 cl i::: .Q 2.5 -4---------------- ----- - ~~'------------------- - --1 f :, "' g 2~----------------~~-------------------- - - - -~ u i::: cu ~ 1.5 4----------------'--~"""---,,._____,~~- ------------------------ - -i Cj 0.5 4-----~---------------------------- ----------i O+-------,----- ---,--- - - ---,---------i--------,---------1 0 0.5 1.5 2 2.5 Tidal Volume (L) Figure 38. Oxygen consumption and tidal volume data from the levels determination session. Shown is the best fit line. 3 4.5 ~---------- -------------------------------, 4-!----- ----- ------------- - ------- -------:;;;,,"""-----, '2 ! 3+-- ------------- ----- - --------=~---------- - -i '-' C .g 2 5 +- ------------- - -------'=-- -~""""------------------------1 0.. . e :::l "' g 2+----------------~.-£----- ------------------------1 u C Cl) ~ 1.5 +------ ------....-::,,""""- -- ---- -------- --------- - ----; )( 0 1 0.5 +--- ----- --------------------- - ------- --------1 0+----- --,---------.-------,--------.-------,--- - -----1 0 0.5 1 1.5 2 Tidal Volume (L) Figure 39. Validation data plotted against the best fit line from regression of oxygen consumption against tidal volume. 2.5 3 30% and eighty percent were within 25%. The errors with the validation data were simi lar to the errors seen with the calibration data. The predictions made with equation 87 were unbiased and a high degree of correlation was found between oxygen consumption and tidal volume. The intercept coefficient was of questionable accuracy; this may have led to the larger errors. However, overall , the model fit the data well. Actual Oxygen Consumption Actual oxygen consumption was determined using the equation for oxygen consumption as a func tion of minute ventilation. This equation was selected over the tidal volume equation due to the larger errors in the tidal volume equation and the intercept coefficient with questionable accuracy. Both equations were determined in order to see which equation was more accurate. Oxygen Deficit Oxygen deficit was found as the difference between the oxygen consumption required by the activity and the oxygen consumption adjusted for the resistance and dead volume of the respirator: 0 2 deficit = V 02,reqwred - V 02,adjusred (93) where: 0 2 deficit, oxygen deficit, Umin 218 Because transient effects were not included in the model, no direct predictions of performance time for respirator wearers may be made. However, the difference between the oxygen consumption required by the activity and the modified oxygen consumption of the respirator wearer would give an indication of the oxygen deficit. Activities with a large oxygen deficit would not be able to be continued for a long time. Peifonnance Time While accurate predictions of perfonnance time can not be made presently, a rough estimate of performance time was added to the model. The predictions of performance time should in no way be considered reliable. This parameter was added for two reasons. The first was to provide very rough estimates of performance time so that different respirators could be compared. The second and main reason was that eventua1Iy the model wilJ be able to make predictions of perfonnance time so performance time was added to provide the structure for future development of the model. Bearden and Moffatt (2000) found that the maximum oxygen deficit for work above the anaerobic threshold was 4.03 L. This value was used as the maximum oxygen deficit in the present model. If the maximum deficit were divided by the actual deficit, a perfonnance time could be predicted. Therefore, the equation for performance time was: 219 P rf . ( 4.03 ) e time= . 0 2 deficit (94) where: Perf time, performance time, min Respiratory Rate and Respiratory Period Respiratory rate was found by dividing the adjusted minute ventilation by the adjusted tidal volume: RR = V E,adjusted V T,adjusted where: RR, respiratory rate, breaths/sec (95) Respiratory period was determined from the inverse of the respiratory rate: 1 RPD=- RR where: RPD, respiratory period, sec 220 (96) Exhalation and Inhalation Times The theoretical model developed by Johnson and Masaitis (1976) was not used to determine the inhalation and exhalation times because preliminary analysis of the data from the inhalation/exhalation study (Johnson, et al., 2001b) indicated that the model was not producing reliable results. Caretti et al. (1992) had indicated that a power-Jaw relationship existed between exhalation time and respiratory rate. It was believed that if the same relationship could be shown for a large data set, then this relationship could be used to directly calculate exhalation time from respiratory rate. The data from the inhalation/exhalation study showed a power-law relationship similar to that obtained by Caretti et al. (1992) (see Appendix B, Figure 125). The variability of the data in the region below 20 breaths/min was larger than the variability above 20 breaths/min. This variability was seen also by Caretti et al. (1992). Figure 40 shows the exhalation time plotted against the respiratory period, the regression line, and the regression equation. There was a larger variability in the data at the longer respiratory periods. The regression equation was: Tcx1i = 0.6176RPD -0.2145 where: Texh, exhalation time, sec RPD, respiratory period, sec 221 (97) N N N 7~ -----------------------------------------------, • s-i--------- - ------- - - ----------- - ---------- - --- - -----1 • • • 5-1--- --------- ---- ---- ------------ - ----------- ---::--------I O+-------,-------.------.---------.- - ---.-------,--------,-- ----,-- ------i 0 2 3 4 5 6 7 8 9 Respiratory Period (sec) Figure 40. Exhalation time and respiratory period calibration data. Shown is the best-fit line. The analysis of the regression line resulted in the following statistics: R= o.93, ScfSy = 0.36, Se(b1)/b1 = 0.01, Se(bo)/bo = -0.03, and bias= 0.00. These statistics indicated that the model was accurate. The fact that the ratio Se/Sy is much less than one indicates that the predictions made with the model are a significant improvement over predictions that would be made using the mean. The standard error ratios for the slope and intercept coefficient are close to zero, which indicated that they are reasonably accurate. Finally, the model provided unbiased estimates and had a high correlation coefficient. The residuals showed that as respiratory period increased, the spread of the predicted values increased (see Appendix B, Figure 126). However, the same pattern Was seen with the raw data: there was more variability as respiratory period lengthens. This variability was seen by other researchers (Caretti et al., 1992). It seemed logical that if the raw data had a higher variability in one region then the predicted values would exhibit a higher variability as well. Analysis of the percent errors in the residuals indicated that there were 722 predicted values that were greater than ± 20%, 110 greater than ±40%, and 1 greater than ±100%. This meant that 84% of the predicted values were within ±20% of the actual value and 97.5% were within ±40% of the actual value. The validation data and regression line are shown in Figure 41. The resulting regression equation was: 223 N N ~ ?~ - ------- - ----- - ------------------------------, 6 • 5 ,....., u ~ ~ ~ 4 E i=- C _g .; "t; 3 ..c:: >( Ul 2 0+-- ---..--- ---,------ ,--- - --,--- ---,----- --,,----- --,------,,--------i 0 2 3 4 5 6 7 8 Respiratory Period (sec) Figure 41. Exhalation time and respiratory period validation data plotted with the linear regression line obtained from the calibration data. 9 Texh == 0.627RPD - 0.2325 (98) The calculated t-values were 0. 73 and -1.59 for the slope and intercept coe[f' · Icients, respectively. Both t-values were within the accepted range. Thus, the null hypothesis was accepted. The slope and intercept coefficient obtained for the validation data were the same as the slope and intercept coefficients for the calibration data. Caretti et al. (1992) showed that a power-law relationship existed between exhalat1· · · 1 · · d' d h on time and respiratory rate. The current ana ys1s m 1cate t at a similar relationship existed. The change of variable from respiratory rate to respiratory Period simplified the statistical analysis. The statistics indicated that the model (equation 98) provided an accurate, unbiased prediction of the exhalation time over th e range of respiratory periods from 0.9 to 8 seconds. During exercise, inhalation time can be obtained by subtracting the exhalation time from the respiratory period. At rest, there is a brief pause between exhalation and inhalation. Bre th · a mg Wav~fonn Based on Work Rate The inhalation waveform changes from sinusoidal at rest to trapezoidal during moderate intensity exercise. The exhalation waveform begins as an exponential at rest and b .d 1 d · exercise When flow rate becomes limited ecomes trapezo1 a unng · durin h . . xponential (Johnson, 1991). While g eavy exercise, exhalat10n becomes e 225 Johnson and Berlin (1974) investigated the transition from a trapezoidal exhalation waveform to a limited-flow exponential, the work rate at which the waveforms transition fr · ·ct · · d · 1 h 1 · om smuso1 al mhalat1on an exponentia ex a at10n to trapezoidal is Unknown. The waveform transition was assumed to occur at 40% V ozmax· At heavy work rates, there is a partial coJlapse of the airways due to high external pressures and high internal flow rates (Johnson, 1993). Because of this, flow becomes limited. Johnson and Berlin (1974) found that limited expiratory flow was a fact · or m termination of exercise for young men wearing respiratory protective masks. The exhalation time at exhaustion was 0.66 seconds. Therefore, when exhalation time was 0.66 seconds or below, the exhalation waveform was assumed to be a flow- limited exponential. Re · spzratory Work Rate Respiratory work rate equations for sinusoidal, trapezoidal, hybrid exponential, and flow-limited hybrid exponential waveforms were obtained from Johnson (1993). Values for the Rohrer coefficients, compliance and inertance were tak en from the same study. 226 Implementing and Evaluating the Model The model was implemented in a Visual BASIC program. Default values were Provided for all inputs so that a user could start the program and run it without entering any values. Four respirator conditions were possible. The default condition Was no respirator worn. The U.S. Army Ml7 and M40 masks were possible options. These were added because these masks have been used in many studies. Data from th e literature could be simulated by selecting one of these two masks. The fourth option was to allow the user to enter values for inhalation and exhalation resistance ' dead volume, and mass. Four possibilities were available for the external work rate as well. The user could choose to enter a work rate, select a treadmill speed and grade, select bike ergorneter values, or select stepping values. All outputs were displayed in text boxes on the screen. Buttons were provided to allow the user to get to the forms where the data was entered. The name of the output file could be chosen by the user. The program was intended to be user friendly and easy to use. The program Was structured so that future development of the model could be incorporated easily. The evaluation of the model occurred in three stages. The model equations Were first checked to ensure that they had been entered correctly. Data from six subjects was then used to evaluate the model predictions. FinaJJy, simulations were run f d. · or a respirator and no respirator con 1tion. 227 Model Equations The input values given in Johnson (1993) were entered into the current model a nd the results compared to the results presented in the paper. The work rates for the sinusoidal, trapezoidal, hybrid exponential, and limited-flow hybrid exponential obtained with the current model matched those presented in Johnson (1993). Other equations in the model were checked by calculator and by spreadsheet to ensure that mistakes had not been made either in entering the equations or in the logic that dictated their use. In all cases, the model and validation calculations were equal. s b ' u '}ect Simulations Demographic data for subjects 002, 224, and 230 are shown in Table 17. Vo2max (Umin) 2.38 3.45 3.23 The test conditions for each stage are presented in Table 18· Table 18. Treadmill speeds and grades for the five stages. Speeds are in mis and rades are in ercent. The infonnation is resented ass eed/ rade. 002 224 230 0.76/0 1.12/0 1.21 /0 1.57 /0 1.7/0 1.7/3 1.7 IO* 1.97/6 2.15/4 1.97 I 10 * Subject was at 60% V 02max, below the targeted 65-70%. 228 The plots of the actual and model simulation results for oxygen consumption, minute ventilation and tidal volume are shown in Figures 42 - 44. Clearly, the model d' td not make very good predictions. Percent errors for oxygen consumption, minute Ventilation, and tidal volume, respectively ranged from -57 to 15, -66 to 58, and -58 to 9. As minute ventilation and tidal volume are functions of oxygen consumption, errors in determining the oxygen consumption will be compounded when minute ventilation and tidal volume are determined. Possible errors in detennining the oxygen consumption were errors in the relationship between oxygen consumption and Physiological work rate and errors in determining the physiological work rate. Physiological work rate in this model was determined from the external work rate and efficiency. It was known that there were problems with detennining external Work on a treadmill. Additionally, the efficiency equation was evaluated using a small number of data points. As mentioned previously, errors in one relationship get compounded when other parameters are based on the faulty relationship. As the Pandolf et al. (I 977) equation has been shown to make accurate predictions of Physiological work rate for subjects exercising on a treadmill (Myles and Saunders, 1979), it was decided to use the Pandolf equation for all subjects exercising on a treadmill. This bypasses the external work rate and efficiency calculations. Additional work should be perfonned to investigate improvements in detennining extemaJ work rate and efficiency. 229 N vl 0 3~---------------------------------------:::;>'I <> no mask 2.5 -- · - - -- identity b. mask -------- ---- ------- --- 2 - - -------~----~--- C: ., bl) >. >< ---- ---- 0 -0 ¾ 1 -- a cil u <> <> <> <> <> Q-¥'--------,--------,---------,---------,-------,.---------1 0 0 .5 1 1.5 2 Measured Oxygen Consumption (Umin) Figure 42. Oxygen consumption calculated by the model compared to measured oxygen consumption. 2.5 3 N w - 60 50 '2 ·e ~ C 40 0 -~ -~ Ill > ~ :::, 30 C i -0 ~ C no mask --identity ~ mask <> <> <> ~ <> 0-1"'-------.--------..------.....-------..----------.--------.------' 0 10 20 30 40 50 60 Measured Minute Ventilation (Umin) Figure 43. Minute ventilation calculated by the model compared to measured minute ventilation. 1.4 1.2 ~ 1 u e ::s 0 > ca "Cl i= "Cl u o no mask -- identity ~~---- A mask <> ~ 0.6 ---- <> <> _______ _.,,.,.e:;___ _____________ _____ ______ _ a ca u 0.4 -------- <> <> <> A <> <>--------- ----- - - - ------ 04£------,-------,----- --,------,---- ----.--------.------r-----' 0 0.2 0.4 0.6 0.8 1 1.2 1.4 Measured Tidal Volume (L) Figure 44. Tidal volume calculated by the model compared to measured tidal volume. The reason for trying to use external work rate and efficiency instead of equations such as Pandolf was that the external work rate/efficiency method should be applicable across different physical activities. Equations such as Pandolf and th ose developed by ACSM (2000) are applicable only to certain activities. As respirator wearers are not always walking on a treadmill, stepping, or cycling, a method of detennining the physiological work rate is needed for various activities. The relationship between oxygen consumption and physiological work rate Was evaluated also. The graph presented by Astrand and Rodahl (1970) and the equation developed here (equation 55) showed a zero-intercept linear equation. The data from the current study are shown in Figure 45. The linear regression equation fit to the data was: V02 = 0.0028WRphys + 0.4398 where: WRphys, physiological work rate, W V 02, oxygen consumption, Umin (99) The slope is very close to the slope of equation 55 (0.0029). However, equation 99 shows that there is a large intercept. Both the slope and the intercept were found to be significantly different from zero. The correlation coefficient was 0.98, the bias Was zero, and the standard error ratio was 0.21. AII of these statistics indicated that equation 99 was statistically valid. The standard error ratios of the slope and Intercept coefficient were 0.04 and 0.14. Values less than 0.3 to 0.4 indicate accurate Predictors (Mccuen, 1993 ). 233 4.5 ~-------------------------------------------, 4+------ - --- --------------- -------------------------i ,..._ C ! 34---------------------------------=1~:__ _________ ____ ------i C 0 ·g_ 2.5 -1-- ----------------------::;.,,.'=-----.C'<'c___ __ _ _ _ ___________ -----i E :::, "' g 2-1----------------- -~""------------------- -------, u C '& 1.5 -1----------~~~----'"'-----=----':__ _______________ __________ -i >, x 0 0.5 +----------------- -------------------- - ------------1 O+--------,--------,-------r-------,--------,--------....--------1 0 200 400 600 800 1000 1200 Physiological Work Rate (W) Figure 45. Required oxygen consumption and physiological work rate. Data are from the levels determination session from the current study. 1400 Equation 99 replaced the previous relationship between oxygen consumption and physiological work rate in the model. The physiological work rate was determined from the Pandolf et al. (1977) equation. Model simulations were run a . f gam or subjects 002, 224, and 230. Plots of the calculated versus measured oxygen consumption, minute ventilation, and tidal volume are shown in Figures 46 - 48. The percent errors for oxygen consumption, minute ventilation, and tidal volume, respectively ranged from -28 to 18, -27 to 88, and-32 to 15. Three of the errors for tidal volume were greater than fifty percent. The rest of the errors were below 21 %. The modified model made much better predictions of oxygen consumption, minute ventilation, and tidal volume than the original model. The errors in the calculations here are of a similar magnitude to those of the original equations. The plots of the data from the three subjects who participated in the inhalation 1 exhalation resistance study for oxygen consumption, minute ventilation, and tidal volume are shown in Figures 49 _ 51. The oxygen consumption and minute ventilation are consistently under-predicted. Errors in the prediction of oxygen consumption, minute ventilation, and tidal volume, respectively ranged from -52 to 4 l, -48 to o, and -31 to 73. The model was not making accurate predictions at high Work rates. There were large decreases in the minute ventilation due to the resistance of the respirator. If there were an error in detennining the adjusted minute ventilation, then there would also be an error in detennining the adjusted oxygen consumption based on that minute ventilation. A multiple regression equation was fit to the minute Ventilation and inhalation and exhalation resistance data to detennine if there were a 235 N I.>) 0\ 3~----------------------------------------:;.., '2 2.5 ·e d C 0 0.. 2 E ::I V) C 0 1.5 u C cu 0.1) :>-. >< 0 1 "C) cu ... ~ ::i u tsi u 0.5 <> no mask -- identity ~ mask --- - -- - -- <> ~ <> o~------~------,----------,---------.--------,---------1 0 0.5 1 1.5 2 Measured Oxygen Consumption (L/min) Figure 46. Oxygen consumption calculated by the model compared to measured oxygen consumption after changes to the model. 2.5 3 60 --- - -- ·- -------------- --- ,-... C ~ 50 .._, C .9 ] 40 = ~ ~ 30 C <> no mask -- identity b. mask ---~ - ---·-- ------ i ~ <> <> 0-¥'-------,--------,---------.--- ---,-------.--------,--~ 0 10 20 30 40 50 Measured Minute Ventilation (Umin) Figure 47. Minute ventilation calculated by the model compared to measured minute ventilation after changes to the model. 60 N w 00 1.4 ---- <> ¢ no mask A 1.2 ~ ,-.., --identity ....l mask .._, A Q) 1 8 :, 0 > 0.8 ~ "C:) ~ "C:) Q) 0.6 .... <> "' ::i u ~ ¢ u 0.4 - -- 0.2 ~ 0 0 0.2 0.4 0.6 0.8 1 Measured Tidal Volume (L) Figure 48. Tidal volume calculated by the model compared to measured tidal volume after changes to the model. A ----- 1.2 1.4 N w \C 5 4.5 ,-... C "§ 4 :) .._, C 3.5 .S! .... 0.. e ::l , >< 0 "'O Q) .... c,s "3 u ca u 3 <> 2.5 <> <> <> 2 <> <> <> <> 1.5 <> 1 0.5 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Measured Oxygen Consumption (Umin) Figure 49. Oxygen consumption calculated by the model compared to measured oxygen consumption for subjects who completed a study on inhalation and exhalation resistance. 4.5 5 N ~ 0 120 ---------------------------------------~ 100 ,...._ i:: ·e ~ ..__, i:: 80 .9 .E ~ 0 > 60 0 '5 i:: 'i "1::1 40 0 -t '"a ""O ~ ""O ct) -t'3 "'3 u '"a u 2 1.5 1 0.5 0 0 0.5 1 1.5 2 2.5 Measured Tidal Volume (L) Figure 51. Tidal volume calculated by the model compared to measured tidal volume for subjects who completed a study on inhalation and exhalation resistance. 3 drastic dift b erence etween the effect of resistance with these subjects and the effects shown in th d e stu y conducted as part of this research. The resulting equation was: VE ::: l.48 - 0.024Rinh -0.0758Rexh where: Rinh, inhalation resistance, cmH20/Us Rexh, exhalation resistance, cmH20/Us VE, minute ventilation, Us (100) The slopes of the above equation are similar to those for the equation developed previously. The slopes of equation 79 were -0.045 for inhalation resistance and - 0 · 0967 for exhalation resistance. So, it does not appear that the previously developed equ . ation x was unreasonable. Two possible reasons for the discrepancy between the predicted and actual Values could be the small sample size and the fact that equation 79 was based on average minute ventilation values. Because of the variability in physiological data, Using small sample sizes can lead to errors in equations fit to the small sample. I-Iowever, as was discussed previously, the slopes of the inhalation and exhalation resistance are consistent with values found in the literature. The present slopes do d 'f . 1 fer from those found by Johnson et al. (1999) and Carett1 et al. (2001). Caretti et al. reported that the effects of inhalation resistance were three times greater than those of exhalation resistance. Perhaps the results of the study on the combined effects of inhalation and exhalation resistance (Johnson et al., 2001b) will help resolve this difference. 242 Model simulations were run using data from the stage 5 respirator condition B from the current study. The percentage errors for oxygen consumption, minute ventilation, and tidal volume ranged from -36 to 14%, -34 to 2%, and -38 to 34% ' respectively. These errors are cJoser to the errors of the original equations. This Would be expected since the equations were based on the data of these eight subjects. B t · u , It does show that the mode] was performing as expected based on the sma11 population on which the equations were based. The second possible reason for the discrepancy in predicted versus actual Values is that average minute ventilations at each stage were used to make the predictions of the effects of inhalation and exhalation resistance. AdditionaUy, the regression equations for the effects of resistance assume that the amount of the decrease in minute ventilation is dependent on the resistance and work rate only and not on the minute ventilation with zero external resistance. The percent change in minute ventiJation may be a better approach than an absolute change. To investigate the possibiJity of using percent changes in minute ventilation, the difference in minute ventilation from the Jeve]s detennination session to each of the respirator conditions was determined for stage four for the eight subjects who Participated in the current study. The results are shown in Table 19. 243 -~:~le 19 R Pe~cent changes in minute ventilation for subjects exercising at 65-70% of max- esmrator conditions are compared to the levels session. _Subject Respirator A Respirator B Respirator C J)Ol -4.3 -11.6 0.66 _002 -1.3 -2.6 -0.7 _023 -2.5 -3.2 0.3 _!45 -6.6 -1.2 -7.3 _173 -4.4 -10.3 _114 -15.9 -24.8 -25.4 221 6.5 -3.2 -3.9 ---231 -0.6 1.2 2.4 The percent changes show the variability in the response of the subjects to external resistance. Subject 214 evidenced large decreases in minute ventilation while subject 231 appeared to be relatively insensitive to changes in resistance. Subjects 001, 023, 221, and 231 each had at least one instance where minute volume increased with the resistance. These increases were relatively small although subject 221 had a 6.5% increase in minute ventilation going from the levels session to respirator A. It does not appear that using percent changes in minute ventilation would result in better predictions. Some subjects are more sensitive to resistance than others. Perhaps individual multiple regression equations should be developed that relate minute ventilation not 0 nly to inhalation and exhalation resistance but also to other factors such as anxiety and respiratory resistance as well. Further investigation would be necessary to detennine if such equations would improve the prediction accuracy of the mode]. Johnson et al. (1999) also had some subjects who were insensitive to resistance. Those authors were unable to determine a distinguishing factor among those subjects. 244 - - - - A study should be conducted in which a large number of subjects perform exercise at a variety of work rates while wearing respirators with different combinations of resistance and dead volume. This data would be used to examine the model equations and the validity of the overall model. Sufficient data to conduct a full validation and sensitivity analysis of the model was not available. Mask/No Mask Simulations Plots of adjusted minute ventilation, adjusted tidal volume, adjusted oxygen consumption, respiration rate, inhalation time, exhalation time, inspiratory work rate, expiratory work rate, inspiratory work, expiratory work, total respiratory work, and total respiratory work rate versus percent of maximum oxygen consumption obtained from model simulations of mask and no mask conditions are shown in Figures 52 to 63 · The % V 02max was obtained from the required oxygen consumption for both the mask and no mask conditions so that direct comparisons could be made. 245 r 70.00 <> no mask 60.00 --~-·-- ~----- c 50.00 ·e ~ g 40.00 ~ c > 30.00 B ;:) C i 20.0 0 --- 10 . 00 0 . 00 0.00 omask -- Q <> 0 0 10.00 20.00 30.00 <> <> 0 0 40.00 50.00 60.00 Percent of Maxi.mum Oxygen Consumption (%) Figure 52. Minute ventilation from model simulation. <> -- -Q 0 0 70.00 80.00 90.00 r 1.80 1.60 1.40 1.20 3 .._, 6 1.00 ::, 0 > -;; 0.80 "Cl i= 0.6 0 0.4 0 ---~ -- 0 . 20 0 . 00 0.00 <> no mask I a mask a a <> <> a <> Q - 10.00 20.00 30.00 40.00 50.00 60.00 Percent of Maximum Oxygen Consumption (%) Figure 53. Tidal volume from model simulation. -e <>

, x 0 ] 1.0 0 "' ::,. ~ < o . 0 50 . 00 0.00 <> no mask o mask - V ~ D - D .... <> <> 10.00 20.00 30.00 40.00 50.00 60.00 Percent of Maximum Oxygen Consumption (%) Figure 54. Oxygen consumption from model simulation. <> -- <> n D 70.00 80.00 90.00 r 50.00 45.00 40.00 35.00 ,,......_ C ·e e 30.00 * ~ 25.00 >. .... 0 "' .:: 20.0 0 ~ ~ 15.0 0 - 10.0 5. 0 0 00 .00 <> no mask - --------- - o mask <> - -· <> ------------ - - D - - - - a ------- -- ~ 0.00 10.00 20.00 30.00 V ~ n D 40.00 50.00 60.00 Percent of Maximum Oxygen Consumption (%) Figure 55. Respiratory rate from model simulation. <> - <> .... 70.00 80.00 90.00 1.60 1.40 -- 1.20 ,...._ u 1.00 0 "' .._, e ~ 0.80 -~ ~ «i -§ 0.6 0 - 0.4 0 0. 20 0 .00 0.00 a <> no mask a mask a a a <> <> _o <> 10.00 20.00 30.00 40.00 50.00 60.00 Percent of Maximum Oxygen Consumption(%) Figure 56. Inhalation time from model simulation. a -u ~ <> 70.00 80.00 90.00 2.00 1.80 1.60 1.40 <> no mask ·--- D mask - - - - ,....., g ~ 1.20 ~ E ~ c: 1.00 0 -~ ] 0.80 >( Ill 0.6 0 0 0 - - --- - - --- .. 0.4 0.2 0. 00 0.00 10.00 - - D D D <> <> <> <> 20.00 30.00 40.00 50.00 60.00 Percent of Maximum Oxygen Consumption (%) Figure 57. Exhalation time from model simulation. CJ D <> <> 70.00 80.00 90.00 6.00 5.00 ~ 4.00 0 '.a p:::; ~ ... ~ 3.00 i:: _g ~ ~ ~~~ -g 2.0 0 -- - 1.0 0 0. 00 0.00 <> no mask Dmask f---------- D -.... <> ~ <> 9 10.00 20.00 30.00 40.00 50.00 60.00 Percent of Maximum Oxygen Consumption (%) Figure 58. Inspiratory work rate from model simulation. D <> -- D <> 70.00 80.00 90.00 r 18.00 16.00 ---- <> no mask omask 14.00 [ 12.00 ------ ~ ci:: .i.: 10.00 6 ~ § 8.00 ·~ tU ~ 6.0 ~ 0 4.0 0 - ~ 2. 00 0 .00 0.00 - 10.00 ~ <> -a D 70.00 80.00 90.00 6.00 -,-----------------------------------------, 5.00 -- <> no mask omask D e 4.oo ~ --·--------------------------·------------------------------ ~ ... 0 D <> ~ 3.00 -------------------------------------------------------- t: .9 ~ ea .i::: <> .S 2.00 ----------------------------------- ------------ D 1.00 - - --·----------------------~D~---------- - --------- D <> <> <> 0.00 +-----,------,-----,------,------,-----,------,------,c-------1 0.00 10.00 20.00 30.00 40.00 50.00 60 .00 70.00 80.00 90.00 Percent of Maximum Oxygen Consumption(%) Figure 60. lnspiratory work from model simulation. r N \J\ \J\ 12.00 <> no mask 10.00 -- o mask 6 a.oo ·---------- z ....., .¥ ... 0 ~ 6.00 i:: 0 -~ ca .J:: )( l,.I.l 4.0 0 2.0 0 0 .00 0.00 ---- ~ 10.00 20.00 D e <> ~ 30.00 40.00 50.00 60.00 Percent of Maximum Oxygen Consumption (%) Figure 61. Expiratory work from model simulation. <> .., ¢0 70.00 80.00 90.00 E 6 .:.:: ... 0 ~ >--. ... 0 ea ... ·5. "' 0 ~ N "@ V1 0 °' E,-< 16.00 ~-----------------------------------, 14.00 12.00 10.00 8.00 6.00 4.00 - <> no mask o mask -- -------~- - -~-----·--- -- ---- -------- D D 2.00 ---------------- ------- -----~--- -- --------------~ <> ---o <> -- - <> - - D 0.00 +----~---~----------------~---~-----.-----! 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 Percent of Maximum Oxygen Consumption(%) Figure 62. Total respiratory work from model simulation. 12.00 <> no mask 10.00 -,~ V ---- Dmask ~ ......, ~ 8.00 -~ «I ~ .!>( ... 0 ~ ~ 6.00 ·-- 0 D 2.0 0 ·- D ~ <> Ci (iii 0 .00 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 Percent of Maximum Oxygen Consumption(%) Figure 63. Total respiratory work rate from model simulation. The model simulation of the no mask condition will be discussed first (see Appendix C, Table 69 for the simulation data). As work rate increased, physiological work rate, required oxygen consumption, minute ventilation, and tidal volume increased, as expected. The increased physiological work rate was due to the added mass of the respirator. The general shapes of the minute ventilation and tidal volume curves were similar to curves of the average values seen for the levels detennination session of the current study. The minute ventilation of 17.5 Umin was higher than expected for a person at rest. Resting minute ventilation is typically around 6 Umin (Johnson, 1991). However, the subjects in the current study frequently had resting minute ventilations of 10 to 18 Umin . Respiratory rate decreased and then increased as work rate increased. This effect was seen also for the average respiratory rate obtained during the levels detennination session of the current study. During the levels detennination session, as Work rate increased from stages one to two and stages two to three, the percentage changes in tidal volume were greater than the percentage changes in minute ventilation. This caused the decrease in respiratory rate. From stage three to four and four to five, the percentage changes in minute ventilation were much higher than the changes in tidal volume, resulting in an increase in the respiration rate. The pattern of the respiratory rate seen here is contrary to that shown in the literature. Silvennan et al. (1951), Harber et al. (1984), and Hermansen et al. (1972) showed that for constant-rate exercise, respiratory rate increased as work rate increased. The model behavior is a result of the data to which the curves were fit. Possible reasons for the 258 discrepancy could be the small sample size or incorrect determinations of steady-state values. Care was taken to ensure that the steady-state values were accurate. While minute ventilation and oxygen consumption values were typically steady, tidal volume fluctuated particularly at low work rates. The fluctuations are likely due to the fact that there is more voluntary control of breathing at the lower work rates. The tidal volume data from the current study were averaged over three minutes, which should have decreased the impact of a single large or small breath. However, if large changes in tidal volume occurred throughout the three-minute sample, then the average value would be affected. Inhalation and exhalation times increased and then decreased as work rate increased. This was a result of the pattern for respiratory rate. Higher respiratory rates are associated with shorter inhalation and exhalation times. As respiratory rate decreases, the inhalation and exhalation times lengthen. Respiratory work rate increased as the physiological work rate increased. This was true even with the shortened inhalation and exhalation times at rest in part because the respiratory waveform was chosen based on the work rate and not the inhalation and exhalation times (except for the flow limited case). Using the values for respiratory work rate and inhalation and exhalation times given in Johnson (1993), the total . k f . ub,iect with sinusoidal inhalation and hybrid respiratory wor or a resting s J ex . ode! predicts total respiratory ponential exhalation was 0.62 N·m. The current m Work f O . . A h parameters (minute ventilation, 0 .56 N·m for a resting subJect. st e inh I . (!993) model were hypothetical, a ation and exhalation times) in the Johnson d' the respiratory work predicted by the irect comparisons cannot be made. However, 259 current model . f h . 1s o t e nght magnitude. The total respiratory work rate predicted by Johnson (1993) · · was 0.14 W which 1s much lower than the 0.40 W predicted by the current model Th' · d · 1s 1s ue to the short exhalation and inhalation times predicted by the curre t n model. The large jump in total respiratory work rate at the highest work rate is duet th 1· . 0 e 1m1ted-flow exponential waveform. The exhalation time is below 0.66 so th 1· · ' e 1m1ted-flow waveform was used. As shown by Johnson (1993), exhaling wi th this waveform resulted in a much higher work rate compared with other wavefonns. When simulations were run with a masked subject, the minute ventilation decreased at all work rates. (See Appendix C, Table 70 for the simulation data.) This effect has been shown in previous studies (Flook and Kelman, 1973; Silverman et al., 1951 ; Hennansen et al., 1972; Cerretelli et al., 1969; Caretti and Whitley, 1998; Johnson et al. , 1999; Caretti et al., 2001). At rest and for work rates one and four th ere Were small changes in tidal volume. At rest and work rate one, the tidal volume was increased due to dead volume. At stage four, the increase was due to the increased physiological work rate and required oxygen consumption caused by the respirator mass. The second work rate showed a large increase in the tidal volume. This was due to a combination of the resistance and dead volume. Flook and Kelman 0 973 ), Silverman et al. (1951 ), and Hermansen et al. (1972) showed increases in tidal volume due to resistance at low work rates. Dead volume was shown to increase tidal volume during light exercise (Stannard and Russ, 1948). For the third work rate, the smal) increase in tidal volume was due to the increase in dead volume compared to the no mask condition. The increased tidal volume at the fifth work rate was due to 260 the resistance. The regression equation obtained for the resistance effects on tidal volume for the current study had a positive slope for exhalation resistance and a negative slope for inhalation resistance. As the magnitude of the exhalation slope was larger than the magnitude of the inhalation slope, the tidal volume increased over the no mask condition. Silverman et al. (1951) and Hermansen et al. (1972) found that tidal volume decreased at high work rates while Caretti and Whitley (1998) found no effect of resistance on tidal volume at high work rates. The results of the current study conflict with these results. Tidal volume did not fluctuate as much during the high work rates as it did during the low work rates, so that should not be a problem with the current data. Caretti and Whitley (1998) adjusted the external work rate for each respirator condition so that the subject was at 80-85% V ozmax for each test. It is possible that an increase in tidal volume due to the increased external work rate was offset by a decrease in tidal volume due to the resistance. Small sample sizes may be a problem as well. Eight subjects and three resistance combinations were used in the current study. Silverman et al. (1951) and Hermansen et al. (1972) both used two resistance combinations. Perhaps the true effect of resistance at high work rates was not seen in either the two published studies or in the current study. Adjusted oxygen consumption increased at rest and work rate one. Decreases in the adjusted oxygen consumption occurred for the higher work rates. The increases at rest and the lowest work rate could be due to the different methods used to calculate minute ventilation from oxygen consumption and adjusted oxygen consumption from adjusted minute ventilation. As minute ventilation is decreased, the oxygen consumption should decrease also. The determination of minute 261 ventilation from oxygen consumption was based on the maximum minute ventilation a nd the percentage of maximum minute ventilation. Adjusted oxygen consumption Was based only on adjusted minute ventilation. As the correlation coefficients for both methods were not one, there were errors associated with the use of each method. The inc · rease m oxygen consumption may be a result of these errors. The decreased oxygen consumption at the higher work rates was due to the effects of resistance. Oxygen consumption has been shown to decrease as resistance Wa ' s Increased (Johnson et al., 1999; Caretti et al., 2001; Flook and Kelman, 1973; Silvennan et al., 195 l; Harber et al.,1984). Respiratory rate for the mask simulation at each work rate is lower than the respiratory rate for the no mask condition. Inhalation and exhalation times were longer With the mask than without at all work rates. This is to be expected. Resistive loading increases inhalation and exhalation times and decreases the respiratory rate (Johnson, 1991 ). This effect was seen in studies investigating the effects of resistance on breathing parameters (Flook and Kelman, 1973; Silverman et al., 1951; Harber et al., 1984; Hermansen et al., 1972). Inhalation work was always higher with the mask than without. Exhalation Work Was higher with the mask up to the fourth work rate. At the fourth work rate, th e exhalation work was nearly the same for the masked and unmasked conditions. The minute ventilation during stage four with the mask is much lower than the minute ventilation without the mask. The components of the work equation are a function of the maximum flow rate that in tum is a function of the minute ventilation. Because the minute ventilation is lower with the mask, the maximum flow is much 262 lower with the mask. This results in a decreased amount of work. Respiratory work should increase when a mask is worn (Johnson, 1992). The error here is likely related to the fact that minute ventilation has been shown to be underpredicted by the current model at high work rates for the respirator condition. A higher minute ventilation Would result in a higher amount of work being performed. At the fifth work rate, the exhalation work rate was much higher without the mask because the flow-limited waveform was used. The flow-limited waveform was used whenever the exhalation time fell below 0.66 sec (Johnson and Berlin, 1974). The mask caused the exhalation time to increase above 0.66 sec for the fifth work rate a nd the flow-limited waveform was not used for the mask condition. The work of inhalation and exhalation were discussed here because the work rate is affected by the inhalation and exhalation times. Summary of Model Evaluation The evaluation of the model showed that for three subjects exercising below 70% V 02max, the model predicted oxygen consumption, tidal volume, and minute ventilation for both respirator and no respirator conditions with the majority of the en-ors in the range of -32 to 21 %. The percentage errors for these subjects were in the same ranges as the errors for the individual equations. However, for three subjects working at 80-85% v 02max while wearing respirators, the percentage errors for oxygen consumption, minute venti lation, and tidal volume were greater than those of the original equations. These errors may result from the fact that the model 263 equations were developed for average responses. Thus, predictions for any one person may have large errors. The comparison of masked to no mask results from model simulations showed that overall the model made rational predictions of the effects of respirator wear. Minute ventilation and respiratory rate were lower with the mask than without. Inhalation and exhalation times and inhalation and exhalation Work were higher with the respirator, as was expected. Many of the equations developed in the model were based on small populations because additional data was not available. One of the benefits of this model was that it showed areas where more information is needed. At the start of this modeling project, it was not known whether or not the selected structure would be functional. Many simplifications were made in developing this model. While prediction accuracy for individuals was less than that for averages, this was to be expected as the equations in the model were based on average responses. Results of this analysis showed that the model structure was valid and that the model was capable of making rational predictions of the average effects of respirator wear on the pulmonary system during physical activity. 264 ... CONCLUSIONS The conclusions that may be drawn from this research were: I. The model of the pulmonary effects of respiratory protective masks during physical activity was implemented successfully. 2 · For three subjects exercising below 70% of V 02max with and without a respirator, 81 % of the model prediction errors were in the range -32 to 2 I%. These errors were of the same magnitude as those of the original equations. 3 · Model prediction errors for three subjects wearing a respirator while exercising at 80-85% of V o2max were greater than the errors of the model equations. 4 · The model did well at making general predictions but did not predict well for an individual. 5 . Overall, the model made rational predictions of the effects of respirator and no respirator conditions for rest and exercise up to 80-85% of V 02max during simulations. 265 6, The model was implemented successfully as a design tool that enabled the user to assess the pulmonary effects of a respirator on a person performing a physical activity. 7 · The program that made up the design tool was structured so that future development of the model could be integrated easily. 266 SUGGESTIONS FOR FURTHER STUDY 1 · An experimental study should be conducted that investigates the effects of a large number of resistance and dead volume combinations on a large number of subjects working over a broad range of constant work rates from rest to maximal exercise. This information could be used to further assess the accuracy of the model equations and the overall model. 2 · Better methods of predicting oxygen consumption based on external work rate for various activities should be investigated. 3 · The existing model should be developed to include effects of training, age, gender, and anxiety on all equations. 4 . The literature should be examined, and, if necessary, an experiment conducted to determine the maximal oxygen deficit. S. Equations should be developed to include transient effects in the model. Transient effects should include the initial changes in pulmonary parameters as activity begins as well as changes due to factors such as oxygen drift and the slow component of oxygen consumption. 267 6 - The equations for respiratory work rate should be developed further to include the effects of frequency and volume on the model parameters. 268 APPENDICES Appendix A Human Subjects Protocol 269 Dept IRB- HUMAN SUBJECTS APPLICATION COVER SHEET rNV ~ Principal In · • .J C / A .f pi) ve5ngator s Name: K4 Cf"' M, O'{"t( ~ I t, v i ['[.,1,, 511!' 1 Date r'i P f. £,R) Address; 1>q1. ,.( A:oloe,c0oP &s . t"I~) 1/oi .1,,,d Mb) Ct, llejg &11K ,t':11? ;?u ~n. HomePhone: ~IO·· y] t;" - 4..; 9$ Campus e: s-- ll I :/ YOu answerea NO honestly 10 a11 PAR·O QUHl1ons. you can De . ·e11sona0Jy sur& rnar you cac, : - I ' sian Decom,ng mucn more pnysaily ac1rv-91n Slowly ana DU/Id - 0 graaual/v, Th,s ,s ine u1es1 ana eas,es1 way 10 90. ,aKe oan ,n a fitness aopra1sa1-m,s ,s an exce.,ent way 10 oererm,ne yo,., basic Illness so 1ha1 you can plan 1ne best w•y tor you 10 11ve lct1ve1v OELAY BECOMING MUCH MORE ACTIVE: • :I vou are no1 faetmq well because 01 a remoorarv ,11n•ss sucn JS a cola or a tevar-wa,1 unut you tee, oener: or ,1 you ~,. or may be pregnan1-1a1~ 10 your aocror D~lo,e YOU sran oecomonq more ac/Jve. PlnM nore: ii your ~ changee so !NI you a-, an_, YES to lll'Y ol lhe aDove QuesNons. rell your htn~ or nu1111 profea10na.1. At« ,.,,.,,,., you s/lOuld c:tJange your l)hy31Ca1 IICIMly Plan. ~"'".a Use of ,n,. PAR.() r~ Canaoan soc,•rw- fa, E•eraa• Phyaooqy. H1t111n C•N101. •ra :r,.., •q•nra assume no 11i101111y lor oarson, wno unoe"1111e Of't¥"ltea110vtfv. Uld eouo, •n., CO"'CNef1"'J ,,,,, QUHlionna.t•. Contutl V04/fl OOC1DI' onot fc, Dft¥"11Cal aCIMFV You are encouraged 10 copy the PAR·O bur only it you use the entire form I lla'le read. understood and compleled this ques11onna11e . Any questions t had were answered to my full satisfaction. ''-'ME--------------------------- ,,Gfg1e a• ,-.x-,e,ce 277 DATE _____________ _ WITNESS ______________ _ SELF-EVALUATION QUESTIONNAIRE Developed by Charles D. Spielberger ,n collaborauon with R. L. Gorsuch, R. Lushene, P. R. Yau, and G. A. Jacobs STAI Form \'•I Name ______________________ Date s ---- - ~----~M __ F_ T - DIRECTIONS: A number or scatemenrs which people have used to deJCribe chemselves are given below. Read each statement and then blaclc:en in the appropriate circle to the right of the statement to indi- cate how you feel right now, chat is. at this moment. There are no right or wrong answers. Do not spend too much time on any one statement but give the answer which seems 10 describe your present feelings best. I. I feel calm ............. .. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · .D 1) (l) © 2. I feel secure .... . .. . . D j) J) ·!) 3. I am tense ........ ... . . .. , · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ;:D 1) (l) © 4. I feel strained ............ , · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · :D J> (l) © 5. l feel at ease .......... ........ .. ······ .. .................... . :D ~ (l) © 6. I feel upset . ........ .. ·,, · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · :D ]) (l) 0 7. l am presenclv 1.-orrvmg o,·er possible misfortunes ........... . . . :D D .'.!) © 8. I feet satisfied ........... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ~ '.!) ,'.!) 1) 9. I feel frightened . ......... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 'D L 1) 0 I 0. l feel comfon:able . . ...... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · J) 'i) (l) ,1) 11 . I feel self-confident ....... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · :D 1) 1) © 12. I feel nervous ..... .... .. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · :D ·:D (l) © ' 13. l am j iuery . . ......... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · (l) 1: 1) © 14. l feel indecish·e ........ , , · · · · · · · · · · · · · · · · · · · · • · · · · • · · · · · · · · · · :D 1J .'.!) © 15. I am relaxed .......... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 'l) t (l) © I 6. I feel content ....... .... .. · , · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · :D l; ~ ~ 17. I am worried ................ , .... , · · · · · · · · · · · · • · · · · · · · · · · · .. :D ,1) (l) © 18. I feel confused .... . , ..... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · • · :D •'l) (l'\ © I 9. l feel steadv ....... , . · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · :D i) (l) © 20. I feel pleasant .... , . . .. · · · , · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · :D ·.D :l) © ---- .....___ __ 278 SELF-EVALUATION QUESTIONNAIRE STAI Form Y-2 :'..:ame ------------------------ Date ------- DIRECTIONS: A number or' statements which people have used to describe themselves are given below. Read each statement and then blacken in the appropriate circle to the right of the statement to in- dicate how you generally feel. There: are no right or wrong answers. Do not spend too much time on anv one statement but give the answer which seems to describe how yo~ generally feel. 21 . I feel pleasant . . . . . .. . . . .. . .. . . ..... .. ........ ... . . ... . . .. ... . 22. I feel nervous and restless 23 . l feel satisfied \\'ith mvself 24. l wish I could be as happ\· as o thers seem to be . .. . .. .. ... .. . . . . 25. l feel like a failure 26. I feel rested '2.i . I am ··calm. cool. and collt:cti:d" 28. l feel that d ifficulties arc p11in~ up so that l cannot overcome them 29. I worrv too much over something that really doesn 't matter . .. . . . 30. I am happ)' . . .. . .. . ... ... ..... . .. . . ... . ... . . . . . . 31. I ha~e d isturbing thoul{hts 32. I lack self-confidr:nce 33. 1 feel secure . . . . . . . . . . . · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 34. I make decisions easilv . . . . · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 35. J 'feel inadequate .. . . · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 36. I am conccnt . . . . . ... . . . . . · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 37. Some unimportant thou~ht runs through mv mind and bothers me 38. take disappointments so kccnlv that I can't put them out of my mind .. .... . .. . ... . . . . .. . .. ... ..... . .. .... .... .... . . . . .. . . 39. I am a stead\· penon .. . . .. .. ... .. ····· ········ ·· ·· ·· · .. .. .JO. I get in a state of iension or wrmo1l as I think over my recent concerns (j) '.i) '.D lj) 1) 'i) 1) fame A.ddress ------------ Phone (day,1 _______ (evening; ________ Age Date of Binh _____ Social Security# _______ Race Personal Physician _______ Address Office Phone -------- . \tt ar ital Status _____ Sex ___ Height ___ Weight Eami l v Historv List nll deceased i rnmediare family members (parents, grand parents nnd brothers: s i 'ire rs, as well as cause of death and age at death. Medications List any current rnedicarions or dietary supplements you may be taking and the rl!.:ison: Alleq:ies (incJude ~d lerf;ies co medications as well) 280 Personal Health r .~n l..! : : : ~,,: Have you had any response : :::~ r·01lowing'? Please circle appropriate high blood pressurl.! yes no heart murmur yes no heart attack yes no s troke yes no J iseases •.) f rhe ..::-cc:-: ... ·: yes no J.ngina yes no rheumatic fever. .. .. .... , ., , ~-· ...... :·;!ver yes no thyroid disease yes no emphysema yes no diabetes yes no bronchitis. pneumo n1:.: yes no yellow jaundice yes no hepatitis yes no kidnev disease yes no Jepression yes no ;.inhritis yes no tuberculosis yes no epilepsy yes no asthma yes no leukemia yes no cancer yes no glaucoma yes no elevated cholesterci yes no polio yes no diprheria yes no Have you ever expe ri .:nced any of rhe following'? Please circle appropriate respon st! : ., 281 frequent headaches frequent colds nose bleeds recurrent sore thro;.:ts wheezing spells coughed up blood coughing up phlegm heart palpitations _chest pain w/ex.ercist! dizzy spells shortness of breath swollen feet/ankles heartburn or intest in;,ii problems pain or cramps in k~s painful J omts ulcers recurrent cons tip:w on recurrnet diarrhe;.: prostrate trouble kidney problems phlebitis varicose veins osteoporosis yes yes y es yes yes yes yes yes yes yes yes yes y es yes yes yes yes yes yes yes yes yes ves no no no no no no no no no no no no no no no no no no no no no no no Smokjng Check tlil! .: ppropri:.1te response below. never smoked _ , topped more than l O years ago smoke up to I pack/JJy _ smoke 1-2 pack/day._ 3+ pack/day What type of smoking.' 1 ..: ircle :.ill that apply) pipe . - 282 cigarette cigar .:\lcohQl How many :iicoholit.: i' :! \'er:iges per ·.veek do you consume'? (circle une, none up to .:/ wee k : · i/week 7-10/week 10+/week What type of alcohol du ~ ,1u drink? _________ _ E;serci~e ~f you participate in ;i regular Jerobic exercise program such a jogging or soccer. please indicate the frequency and type of ;!Xercise below. Regular ::1e:ins :: or more times/week. Circle one of the r'ol10w1ng: llost Recent Hosp1c:i.liz:rnon and Reason: ________ _ Date and Amount or· L.:ist Blood Donation: --------- For Women On Iv :. Circle :ippropriate responses) Are you .:urrenciy ; regnant? yes Are vou ..:urrenciv -nenscruatin!(? ves . . - , [f yes. are your :-:iens crual cycles regular ( once yes Health r nsurnnce I do have health insur:ince (circle one) yes If yes. my insur:inc.! t 1rganizacion 1s: ________________ _ l do have dencal ,;.J\·er:ige 1drcle one, y es Do Nor Wrire Belo" This line:: no no per month)? no no no Total Number of C.ira1ovascular Risk Factors: ___ _ 284 -tie\ k'f A~~RSITY OF !9 J. V J..£1.K.YLAND INSTITUTIONAL Rl!V!IW BOAIU> Reference: !RB HSR Identification Number- 0/agricOOJ March 2, 2001 MEMORANDUM Notice of Results of Final Review by IRB on HSR Application TO: FROM: Dr. Arthur T. Johnson Ms. Karen M. Coyne Department of Biological Resources Engineering Dr. Marc A. Rogers, Co-Chair Dr. Joan A. Lieber, Co-Chair Institutional Review Board ,100 Lee BuildinK Collel{e Puk, Maryland 20742-5121 301.405.4,12 Tl!L 30!.405,H3H6 FAX RE: Project entitled "The Effects of Resistance on the Relationship Between Tidal Volume, Minute Volume, and Oxygen Consumption During Steady-State Exercise" The lnstitutional Review Board (IRB) concurs with the departmental human subjects review board's preliminary review of the above referenced human subjects application. This application has IRB approval for this human subjects research and has been placed on file in the IRB office. If there are any deviations from the approved protocol, you are required to submit the modifications to your departmental human subjects review committee. !ftherc are any questions about this, please contact either ofus at mr68@umail.umd.edu or 1l39@umail.umd.edu or at extension 54212. Thanks very much. /ref enclosures ··- - 285 Consent Form Title: Th~ effec~ of resistance on the relationship between tidal volume, minute volume, and oxygen consumpuon dunng steady state exercise :·,-:_:7;::::-- --:-:--- - --------------• state that I am between the ages of 8 and 39 Yeai:s ~Jd and wish to participate in a project being conducted by Anhur Johnson, Ph.D., Karen Coyne, and Wilham Scott of the University of Mlll)'land 's Biological Resources Engineering Department on the Co!lege Park campus. The purpose of this study is to assess the effects of breathing resistance on the relat1onsh1p between the volume of air exhaled with each breath, the volume of air respired during one mmute, and oxygen consumption. The data to be obtained from this study will help to quantify the relationships. I unde_rstand that, prior to participation in this study, I will report to the laboratory for an orientation session that will last approximately 30 minutes. At this session, this infonncd consent, which describes the procedures, methods, and individual subject rights for this study, will be given to me for my review. I understand that I wil! be asked 10 complete a medical history ques_tioMaire _that details my medical history, I ~~rsta"? that I will be asked to complete a P AR-Q ques11onna1re that will assess my ability to Partic1patc m physical activity. I understand that I will also be asked to complete a computer-administered survey that will be used to rate my general level of anxiety. I understand that this survey is not a reflection of m~ past or present emotional stability. I understand that an investigator will be present to answer any questions that I may have concerning this investigation and my panicipation. I have been informed that on my first visit for testing I will undergo a maximal exercise test. This test will be done on a treadmill and involves exercise that allows worlc rate to be increased progressively until I become exhausted and decide to end the test or other signs or symptoms dictate the stoppage of this test J Understand that I will probably become exhausted within 9 - 15 minutes during this maximal exercise test. Al.so, I am a ware that this entire session will require about one hour of my time. I understand that my blood pressure, heart rate, rating of perceived exertion, and oxygen consumption will be monitored throughout the maximal exercise test. l understand that performance of any exercise test involves some risk_ to my heart and lungs, which are potentially life threatening. However, I understand that this risk is llllrumaJ for individuals within my age group who have no known symptoms of heart or lung disease. The ( --- ·- ··:- ... ns~ ~~~e~!.~!!l!!i_n or immediately after an exercise test i~ less than or equal to 0.0 I~-. Th~ results of my !· -11Wtnnal exercise t t will be used 10 assess by cardiorespiratory fitness for study part1c1pa11on and to r. . . . . lletehiii_~J!irxer SC level that I will be exposed to for subsequent treadmill tests. I understand tfiat I ill be asked to complete three conditions o.f submaximal treadmill exercise and that i these conditic:ns wi be randomly assigned and will occur on different test days . These test sessions will , I. involve constfnt Jo d exercise at intensities of25-30$, 35-40%, 45-50%, 65-70%, and 80-85% ofmy nwuma1 exyrcise c pacity while wearing either a full-facep1ece maslc with vaned msp1ratory and ·- --... _,.,_,. expiratory'oreathin resistances. J understand that it may be uncomfortable to breathe when wearing the masJc ·~tatty n I am exposed 10 a high Jevel of breathing resistance. I understand that I w!ll exercise at each intensity level until my oxygen consumption has reached a stead_y-state. I ~m aware that u may take 3 to 6 minutes 10 reach a steady-state at each intensity level and that I will be walking on the treadmill for 15 to 30 minutes. J understand that a test administrator will stop a test for medical reasons (e.g., abnormal ECG, heart rate, cu:.) or if there is an unforeseen problem with data collection equipment. These three treatment sessions will occur after my initial maximal exercise test session. I undersrand that each lreatrncnt session will require abour one hour of my rime. I understand rhat the following measures will be obtained at vari~us times thro~ghour ea~h rest session: heart rate, oxygen consumption, minute volume (the volume of air _respired dunng one mmute), tidal volume (the volume of air exhaled with each breath), breathing resistance, ratmg of perceived exertion, breathing apparatus comfort, and thermal sensation. I understand that my blood pressure may also _be taken at various times throughout each rest session, J will also be asked to complete the comput~r-ad11Umste~ State-Anxiety survey, 3 measure of situarional anxiety, before. and after eac~ exer~1s~ session. I also realize that I will complete II test 10 assess the level of resprrarory resistance that exists w11hm my lungs and arr 286 Consent Form passages. I have been instructed that this test will require me to use a mouthpiece and a nose-clip and 10 breathe normally in and out of my mouth while I hold my checks with my hands. I understand that several breaths will be analyzed to record my respiratory resistance but that the test is nonnaJJy completed within S minutes. I understand that all testing procedures will be conducted at lll!lbicnt room temperature (74°F) in an environmentally controlled laboratory. I have been advised 10 get adequate rest the night before each test, to cat breakfast or lunch, and to drink plenty of fluids excluding alcohol and caffeine, before reporting to the laboratory. I understand that I need to bri~g my own T-shirt, shons, socks, and sneakers to wear for all trials. I am aware that I am free to ask questions about this study and withdraw my participation at any time Without any penalty. I realize that the University of Maryland docs not provide any medical or hospitalization insurance coverage for study participants nor will the University provide compensation for any injury sustained as a direct result of participation in this study except as required by law. I understand that I will be asked about my health status before each test session to insure that I have no condition that would jeopardize my safety or health. I am aware that if I am excessively tired, have any musculoskeletal injury, have recently consumed excessive amounts of alcohol, or report to have a cold I will not be allowed to participate in testing. I understand that if this situation should arise that I will be rescheduled for testing at another time once I have fully recovered from my ailment. I understand that accidents may result in bodily injury during physical activity. However, I am aware thai the risk of this is far less during the completely supervised activities used in a research study than in unsupervised exercise or competitive spons. I have been informed that some individuals have experienced minor slcin irritations as a result of the procedures used to obtain heart rates. I understand that this condition is commonly resolved within a short period of time. I understand that any information gathered in this study that pertains to me will be held in the strictest confidence and will not be revealed 10 anyone that is not directly involved with this investigation. I understand that this study has not been designed for my benefit. I understand that I will not rccei ve any monetary benefits for my participation. However, I wi~l .be give~ info~tion reg~din~ my general fitness level. I understand that I am· free to withdraw as a part1c1pant without being penalized many way. I am aware that I may request to withdraw either by word of_ mou1!1 or _in, writi~g. l understand that I must ~ign this informed co11Jent before I will be allowed 10 part1c1pa1e m this mvestigauon. I am aware that I WIii be given a copy of the signed consent form prior 10 beginning my participation. Investigators: Karen Coyne, Arthur Johnson, Ph.D., and William Scot! Department of Biological Resources Engineering University of Maryland College Park, MD 20742 Karen Coync's phone: (301) 40S-l 186 or (410) 675-4578 Arthur Johnson's phone: (301) 405-1184 William Scott's phone: (301) 40S-1199 Volunteer 's signature Witness's signature 287 Date Date IAB APPROVED VALID UNTIL FEB 2 8 2002 UNIVERSITY OF MARYUND- COllEGE PARK MEMORANDUM To: Dr. Marc A. Rogers, Chair Rwnan Subjects Review Committee Department of Kinesiology From: Karen M. Coyne May 15, 2001 Re: Project entitled "The Effects of Resistance on the Relationship Between Tidal Volwne, Minute Volume, and Oxygen Consumption During Steady-State Exercise" originally approved February 19, 2001 The treadmill in our lab does not go slow enough to allow three of my subjects to work in 1?e 25-30% of maximal oxygen consumption range necessary for the project. I would like to amend the above protocol to have these three subjects step up and down a 22.5 cm step at a rate that would put them in the targeted range. Thank you. Advisor's Signature: ~ J )iv.Jc-...____. {/ 288 Appendix B Additional Figures 289 4.5 4 • ••••• •• •• ... • • C .s t 2 .5 ·····~ • • •• • - ::l ~ 2 0 u • ~ ••••• • •• •• • • C ~ 1.5 • •• • •• >-. X 0 0 •••••• • •• 1 ···-· ... ~ • """ . • • .5 • 0 0 5 10 15 20 25 30 Time (min) Figure 64. First test of respirator condition A for subject 145. The five stages of the test were run consecutively without a break. • ~ .... 35 40 4.5 4 1 .. ... , ..... . .. .. . • .... ,~ ~~ ... -· .... , ...., ~ . ~ ..... •• • • ... - ~.-. • •• ..... ..... , • ••• • • • • • • ' • • • ...., .. 0 ...., . • •• • • .... ,_. .5 • ........ .-. ·~ - - - 0 I • • I I I I I 0 10 20 30 40 50 60 Time (min) Figure 65. Second test of respirator condition A for subject 145. After each stage, the subject rested until oxygen consumption returned to baseline. 70 N \0 N c:: 0 ·-= s' ::3 Cl) c:: 0 u 4 3.5 • ... ... .... • 3 2.5 2 1.5 l 0. 5 0 • • • ; ...... • • I I 0 • -···· . ••• .... ~ ..... • ...... . ·. • • • • • ....... .... . -. I 10 20 • ·- - ••• ............ •• • .... • • • • .. . ~ .., I 30 Time (min) • • • ... • ..... •• • • • . ....... ......... ..., I 40 50 Figure 66. Third test of respirator condition A for subject 145. After each stage, the subject rested until oxygen consumption returned to baseline. .... 60 ,-,, C ·-E ;:J .._, C .9 .... e' ::, Cl) C 0 u N C Ill 'O bl) (.,.J ;:,,,._ >< 0 4 3.5 3 • 2.5 2 1.5 1 0.5 0 I 25 26 27 28 29 • • • 30 Time (min) • • 31 - • • • 32 33 Figure 67. Regression equation fit to last four minutes of data for stage 5 of the first test of respirator condition A for subject 145. - • 34 35 N \0 ~ 4.5 4 • • • 3.5 ......... i:: - -• • • • ·-8 3 j • • ......., i:: 0 • ·g_ 2.5 8 ::I c,; i:: 0 u i:: C1) bO >. X 0 • 2 1.5 1 0.5 0 l I 56 57 58 59 60 61 62 63 Time (min) Figure 68. Regression equation fit to last four minutes of data for stage 5 of the second test of respirator condition A for subject 145. • 64 ,-.._ i:: "§ j '-" i:: 0 ·-.,J 0.. E ::, Cl) i:: 0 u i:: N Q) "° 00 Ul ;;,-.. >< 0 4 3.5 - • - - • • • • -• • 3 • 2.5 • 2 1.5 1 0.5 0 I 1 ' f 47 48 49 50 51 52 53 54 Time (min) Figure 69. Regression equation fit to last four minutes of data for stage 5 of the third test of respirator condition A for subject 145. 55 r 3~---------------------------------------, ,....._ C: ~ 2~-- ------ - - ---------- -- ___, C: _g .... 0.. ~ 1.5 +---------------- - -----::.,tl',e:__-- --- - - ------------1 "' C: 0 u C: Cl) ~ 1 >< 0 0.5 -l----- - ------- ----- - - - - - ---- --- - - -------- -----1 04------------~--------------------------- 0 100 200 300 400 500 600 Physiological Work Rate (W) Figure 70. Calibration data and the regression line. 700 800 900 1000 r N \0 -..l "' ~ ::I -0 ·;;; Cl) ~ 0.12 0.1 0.08 0.06 0.04 • 0.02 0 100 200 • 300 400 500 iOO •• ..,~ct• ... 800 -0.02 • -0.04 -0.06 Physiological Wark Rate (W) Figure 71. Residuals for the zero-intercept model relating oxygen consumption to physiological work rate. 900 1 0 N \0 00 20 15 10 5 • • • • • • ...... ... .... • • ••• • • • • • • . • • • .. . - ~· . • • • • • • • ~~· ,.. -.. • .... - ... - • .... • • •• ••• 10 20 • 30 • .40. • f •• 60 70 • EJ •• ••• • • •• 5 - •••• ~ • • ~ • • .... ~. •• •• •• • • • •• • 10 •• .... • -15 ~ • -20 Maximum Oxygen Consumption (ml/kg/min) Figure 72. Residuals for linear regression of anaerobic threshold (mL) against maximal oxygen consumption. 1.5 -.-----------------------------------------------. •• • • • • • 0.5 ••• ~· • • •• • • • "' 0 •• cii .... • ¥' 6 ::I ~ • ·;;:; • • 4) CZ:: -0.5 • N • • • • \0 • • \0 -1 • -1.5 • -2 _..__ ______________________________ _ ____________ __. Maximum Oxygen Consumption (Umin) Figure 73. Residuals for linear regression of anaerobic threshold (L) against maximal oxygen consumption. I..>,) 0 0 15 • • • • 10 ... ~ 5 • • • • ..... • - • • • ... 0 • • • • • •• ' • • ...... • :•.s! ... .. I 20 40 80 . 100 :· ., •• • 5 " ~ ... .. ~ •• ·~ • • • -1 0 -15 • -20 -25 Mass(kg) Figure 74. Residuals for multiple regression of anaerobic threshold (mL) versus mass. • 120 1 0 15 • • • • 10 -.... • • ' 5 • ..... • ~ ... • 0 Vl .;j ::I -0 -5 ·;;; Cl) ~ .# • • .. , ~ . • • • • · 4t:• • • D 10 20 30 • 1§) 60 ib • ••••••• • ..... - •• • ~ ....... • • • • • • •• -10 w 0 - -15 • -20 -25 Maximum Oxygen Consumption (ml/kg/min) Figure 75. Residuals for multiple regression of anaerobic threshold (mL) versus maximal oxygen consumption. "' .; :, -0 ·;;; u ~ w 0 N 3~--------------------------------------------, 2+------------------------ -----------------------1 0 h 20 40 -1 • .. • • ••• • *· .,.biJ . ~. • t. . ... •• • • • • • • • • • • • • • • • 80 • +100 120 1 • ... .... -.- • • • • . ... -2 +------ ----------------.------------ ------------! • • • • • -3 ...__ _________________________________________ __. Mass (kg) Figure 76. Residuals for multiple regression of anaerobic threshold (L) versus mass. 0 3 2 • • • • • • • • • •• • • 1 2 *. ·[ • ' •• 4 5 I • ~ . .. • • • • ••• -1 . .. ... .... • • • • ~ • • • •• • ... -2 • • • • • • -3 Maximum Oxygen Consumption (IJmin) Figure 77 . Residuals for multiple regression of anaerobic threshold (mL) versus maximal oxygen consumption. '2 "§ d c:: .:2 :@ E 0 > £ ::, c:: ~ w 0 ..... 100 90 / 80 70 / 60 50 40 / ~ ~ 30 20 10 0 0 0.5 1.5 2 2.5 3 Oxygen Consumption (Umin) Figure 78. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 001. 3.5 • 4 40 ~---------------------------------------------, 35 -l---------------------------------------,,---------1 c ~ 25 +--- -------------------------------~------------------l t:: .2 ~20.\--------------------------Jlllll'-~------------------------i i: ., > ~ 15 .\-----------------~ttr=:-----------------------------1 t:: i 10 .l----------------------------------------------1 5-l-----------------------------------------------1 O+------.-----,--------,-----..--------r-----,------,-----r------.-----; 0 0.2 0.4 0.6 0.8 1 .2 1.4 1.6 Oxygen Consumption (Umin) Figure 79. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 002. 1.8 2 40 ..-------------------------------------------------, 35 .J___- - - ----- --------------------------------~""------------1 '2 ~ 25 +------- ------ - -------- ------ -~~-------- ---- - - ------! r:: .2 1!20+--------- ---- ---- ---- ---- ---""'-- ------- --- --- --------1 -~ 0) > ~ 15 -½----------- ------- ~tr:------------- ---- ---- ---- ----1 r:: i 10 +-- --- - --- - ----- ---- ------- - ---------- ---- --------1 5-l- ----------------------- --------- ------------ ---l 0+------,------,-------,------r--------.-------,-------,--------,------l 0 0.2 0.4 0.6 0.8 1.2 1.4 Oxygen Consumption (U min) Figure 80. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 023. 1.6 1.8 w 0 -...l 120 --------------------------------------------------, 100-¼----------------------------------------------------l e 0.. d C a ~ c ., > ~ ::s C i 80 60 40 20 o~-----~------~------~-----~-------.--------.-------1 0 0.5 1.5 2 2.5 Oxygen Consumption (Umin) Figure 81. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 145. 3 3.5 w 0 00 '2 ·a BO~-----------------------------------------------, 70 +- -- ---- - ----- - --- - - - ---- ---- -----------------~ ::::350 +- ---- - - - - - - ----- - ------- --- ---~ =------- -------------1 .._, 20 +-- - - ---- ----- --=-- ----- --------- --- - - --- - ------ ~ 10 +-------------- ----- - - --- ---- ----- --- ------ - ----1 O+-----------.-------~---------------..-----------,.--------l 0 0.5 1.5 2 Oxygen Consumption (L/min) Figure 82. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 173. 2.5 3 w 0 \0 120 ~-----------------------------------------------, 100 ,....., = ! 80 = .s ~ 60 c 0 > 0 "5 40 = ~ 20 0+--------,-------.------~------,--------,------,-------r-------i 0 0.5 1.5 2 2 .5 3 Oxygen Consumption (Umin) Figure 83. Steady-state minute ventilation versus oxygen consumption obtained during the levels determination session for subject 221. 3.5 4 w .... 0 90 80 C: .13 70 ~ ~ 60 > 0 ::i 50 C: i E 40 ::, E ·x cu 30 ~ ._ 0 0 10 0 0 • • • • 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 84. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 001. 90 60 ~ 50 '--' C .9 ~ c Q.) 40 > B :::l C i 30 e :::l e .R II) :i C ~ E ::l E • >( o:s ::E w ..... 0 - c w II) u ... II) c.. 90 • 80 70 60 • 50 40 • 30 • 20 • 10 0 0 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 87. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 145. 90 w -~ 80 • 70 ei '-' c:: .9 60 3 • E 0 > 50 0 '5 c:: ~ 40 E ::, E • .>( 30 0 '5 C i E ;:I E .>< i:' 0 ::i 50 C: i E 40 ::l E -~ i 30 ._ 0 ... 2 C: 0 0 ~ 0 p.. 10 0 • • • • • 0 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 90. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 221. 90 \.,l -..J 80 70 ..-.. • ~ ......, C .s ... 60 ~ ·.:: C ~ 50 .... £ :::s C i 40 E :::s • E ">< ~ ~ 30 • ....... 0 ... C 2 0 • 0 ~ 0 11.. 10 0 0 10 20 30 40 50 60 70 80 90 Percent of Maximum Oxygen Consumption (%) Figure 91. Percent of maximum minute ventilation versus percent of maximum oxygen consumption obtained during the levels determination session for subject 231. 100 90~----------------------------------------------, •• 80 J___ _____________ _ ___ _ ____ _ _ _____ ____ ____________ ---; • ~70J___------------ - - - -------------- - - --- ---- ------:.,~--------; ...., C 0 ~ c 60 0 > 0 :5 50 1- - - ----------------- ------- ---...J~-... ---.------------l C i §40+-------- - - - -------- ----- -------;;..;l""--------'IP--- ------- - - -------t E -~ ~ 30-\--------- ------- -------..c-::.a~:------- --------- - - --- ------I 0 c 0 ~20-\-----------------=-----...~tc------- - ----- --- - ------------ ----1 ct 10 -1..----------- -------- - - ------- --- - - ----- ------ - - -----l 0-+------------------------------------------------1 0 10 20 30 40 50 60 70 80 90 Percent of Maximum Oxygen Consumption(%) Figure 92. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for all subjects combined. Shown is the best-fit linear model. 100 90~---------------------------------------------, •• 80 .!--------- - --------------- ----- --------------- - ---1 ~ ~ 70 .!--------- ---- - ------ ------- --- - --- ------,,fC----,,,-----------1 c:: .52 ~ c 60+- ---------- ----------- -----------~~_JL----- -------1 0 > 0 gso+----- --- - - ------- ---- - ------ - --,£..,1\---------------------1 'i §40+-- ---------------- - --- - - - -----:.,,,,,,.~ ---.__ _ _ _ _________ _ --i e -~ :;.30+--- -------------- ---.,.,..------::_,,,.=---- - - - - - ------ -------- --- -l ._ 0 c ~ 20 +---- ---- - ---· ..... ~ - - - - ---- - - - -------------- ----------j ~ . 10 +----- ------- - - --- - - ------ - - - -------- - - ------ - --1 O+----~-----.--------------------r-----,-------,------,--------1 0 10 20 30 40 50 60 70 80 90 Percent of Maximum Oxygen Consumption (%) Figure 93. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for all subjects combined. Shown is the best-fit exponential model. 100 w N 0 90 80 ~ 70 C 0 ~ c 60 u > u '5 50 C i E 40 ::, E ·~ ~ 30 ._ 0 c u ~ 20 u 0.. 10 0 0 10 20 30 40 50 60 Percent of Maximum Oxygen Consumption (%) 70 •• • • 80 90 Figure 94. Percent of maximum minute ventilation versus percent of maximum oxygen consumption for all subjects combined. Shown is the best-fit power model. 100 w N - "' "';;j ;:, -0 ·;;; ., 0::: 0 I 10 20 • 30 40 50 60 70 80 SD -2 • • -4 • -6 • • • -8 • -10 • -12 • -1 4 Percent of Maximum Oxygen Consumption(%) Figure 95. Residuals of percent of maximum minute ventilation of the validation data. l l.,l N N 160 140 • ~ ~· ~ • ~ • 0 0 20 0 0 2 3 4 5 Maximum Oxygen Consumption (Umin) Figure 96. Maximum minute ventilation and maximum oxygen consumption data from the current study. Shown is the best fit line. 6 30 • 20 • • • • 10 ~ - • '2 ·e • --d •• "' 0 ~ ::I .:, ·.;; 0.5 1 1 .5 •2 + 2.5 3 3.5 ~ +4_5 • Cl) ~ -10 • • -2 0 • • • -30 I Maximum Oxygen Consumption (Umin) Figure 97. Residuals of maximum minute ventilation for the calibration data. 0.9 0 .8 0.7 ~ 0.6 ~ ~ 0.5 > .a ~ 0 .4 0 . 3 0 . 2 0 .1 • • - - • .. 0 0 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1 .8 Oxygen Consumption (Umin) Figure 98. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 002. 2 2.5 2 • • • • . 5 • 0 0 0.5 1.5 2 2.5 3 Oxygen Consumption (Umin) Figure 99. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 145. 3 .5 2.5 2 cl 1.5 ..: ... • • • • . 5 0 I 0 0 .5 1.5 2 2 .5 Oxygen Consumption (Umin) Figure 100. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 173 . 3 ~ - 3 2.5 2 3 ___, 0 E ::l 0 1.5 > ca -0 ~ 1 • • • • • 0 .5 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Oxygen Consumption (Lpm) Figure 10 l. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 214. 4 .5 w N 00 2.5 2 3 ,_, 1.5 0 e ::I 0 > ca '"O ~ 0 • ... • l • .5 o' 0 0.5 1 .5 2 2.5 3 3.5 Oxygen Consumption (L/min) Figure 102. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 221. -. 4 d G,) E ::I 0 > "ia -0 ~ 1.2 • 0.8 • • 0.6 • 0 .4 • 0 . 2 o I 0 0 .5 1.5 2 Oxygen Consumption (Umin) Figure 103. Steady-state tidal volume versus oxygen consumption obtained during the levels determination session for subject 231. 2.5 100 90 ~ 80 e 10 :::, 0 > ca 60 -0 ~ E 50 :::, E -~ 40 ~ ._ 0 0 0 10 0 I 0 • • • • 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 104. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 001 . 90 ~ -= 70 60 ~ u 50 E ::3 0 > .a -o 40 ~ E ::3 .s 30 ~ ~ ..... 0 C: 2 0 u ~ ~ 1 0 0 • • • • • 0 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 105. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 002. 90 90 80 ti 70 ._, V E ~ 60 > ca ~ 50 E ::I .§ 40 ~ ~ 'ci 30 0 10 0 • • • • • 0 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 106. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 023. 90 ,...._ ~ 0 e ::I a > ca -0 ~ e ::I e -~ '.:2: .... 0 i: 0 ~ w rt w w 100 90 80 70 60 50 40 30 0 2 1 0 0 , 0 10 20 • - - • • 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption(%) Figure 107. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 145. - 90 90 80 ~ 70 e ~ 60 > ~ ~ 50 E ::s E 40 ·2 ~ 'o 30 0 0 • • • • • 0 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption(%) Figure 108. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 173. 90 [ II) e ::, 0 > cu -0 ~ e ::, e "ij ~ .... 0 c II) vJ ~ vJ II) VI C. 100 90 -.... 80 • 70 60 50 • 40 • 30 ... 20 10 0 0 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 109. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 214. 90 I.,.) I.,.) 0-. 80 70 • ,..., ~ 60 0 E ;:I 0 > cu "0 ~ E ;:I E -~ :::; ._ 0 E 0 u ... 0 c.. • 50 40 • 30 • 20 10 0 0 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 110. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 221. • 90 w w -J 90 80 • ~ 70 0 E ::, 60 0 > ca -0 50 ~ • • E ::, E 40 -~ ::; • '-0 30 E 0 • u ... 0 20 Q., 10 0 0 10 20 30 40 50 60 70 80 Percent of Maximum Oxygen Consumption (%) Figure 111. Percent of maximum tidal volume versus percent of maximum oxygen consumption obtained during the levels determination session for subject 231. 90 100 100 90 • ~ 80 u E 70 ::s 0 > ~ 60 "O i:= E 50 ::s E -~ 40 ~ ._ 0 ~ 30 u u I.,.) ... u I.,.) Q., 20 00 10 0 0 10 20 30 40 50 60 70 80 90 100 Percent of Maximum Oxygen Consumption (%) Figure 112. Quadratic model fit to the pooled data from the eight subjects who completed the current study. 100 90 ~ 80 .._, IU E 70 ::I 0 > "3 60 'O ~ E 50 ::I E ·~ 40 ~ ..... 0 30 c IU u ... &. 20 10 o o 10 20 30 40 50 60 70 BO 90 100 Percent of Maximum Oxygen Consumption (%) Figure 113. Exponential model fit to the pooled data from the eight subjects who completed the current study. 100 90 i 80 '-' 0 E 70 ::, 0 > ei 60 "O i= E 50 ::, E -~ ~ 40 ... 0 E 30 0 u ... ~ 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Percent of Maximum Oxygen Consumption (%) Figure 114. Power model fit to the pooled data from the eight subjects who completed the current study. 5 0 ..... 10 20 30 40 50 60 70 BO !b • -5 • • • • csi ::, :g -10 "' • 0 0:: • -15 • w +>, ,- -20 • -25 Percent of Maximum Oxygen Consumption(%) Figure 115. Residuals of percent of maximum tidal volume for two validation 0.8 0 .6 ... • 0.4 • 0.2 - • • .... • • 0 ~• • • "' 0.5 1 1.5 2 2 .5 • 3 3.5 4 • 4.5 )h ca -0.2 :::, '"Cl • •• • ·;;; u -0.4 p:: -0.6 w -0.8 .i,.. N -1 -1 .2 ~ -1.4 Maximum Oxygen Consumption (Umin) Figure 116. Residuals for VTmax as a function of V02max. 0.008 0.006 • 0.004 - (/) ~ 0.002 • (/) «i :::, • "C "iii 0 (I) a: ID 0.1 0.2 0.3 0.4 0.5 0.6 0 7 • w -0.002 ~ w • -0.004 ... -0.006 Dead Volume (L) Figure 117. Residuals from the change in minute ventilation with added dead volume for resting subjects. -Cl) ::::i ..__. Cl) cij ::, 32 Cl) (]) a: 0.005 0.004 • 0.003 • 0.002 0.001 0 I I I -0.001 0 0.1 0.2 • 0.3 0.4 0.5 0.6 -0.002 • -0.003 -0.00 4 • -0.005 Dead Volume (L) Figure 118. Residuals from the change in minute ventilation with added dead volume for lightly exercising subjects. 0 7 w ~ Ul 0.008 0.006 . ~ 0.004 • en 0.002 ~ en ca 0 :, "C "iii Q) 0 0.1 0.2 0.3 0.4 • 0.5 0.6 a: -0.002 • -0.004 -0.006 • -0.008 Dead Volume (L) Figure 119. Residuals from the change in minute venti lation with added dead volume for subjects lightly exercising at 30% V 0 2max· 0 7 ~ "' ca ::I :'S! "' 0 ~ 0.1 • 0.08 0.06 0 .04 0.02 • 0 I 0.1 0.2 0 .3 0.4 0.5 0.6 -0.0 • 2 ... • • -0.04 I Dead Volume (L) Figure 120. Residuals for the prediction of changes in tidal volume as a function of dead volume for resting subjects. 0 7 w ~ -.) 0.06 0.05 .... 0.04 0.03 ~ 0.02 "' til :, -0 ·.;; 0.01 OJ er: 0 I) 0.1 0.2 0.3 0.4 0.5 0.6 • -0.01 • • • -0.02 -0.03 Dead Volume (L) Figure 121. Residuals for the prediction of changes in tidal volume as a function of dead volume for subjects lightly exercising. 0 7 0.2 0.15 • • 0.1 • • • 0.05 -~ ~ • "' -;:; 0 = -0 ·;;; ., 0.2 • 0.4 0.6 • 0.8 1 1.2 1 4 ~ -0.05 • • • • -0. 1 • • -0. 15 .... -0 .2 I Dead Volume (L) Figure 122. Residuals for the change in tidal volume as a function of dead volume and work intensity. c ·e d "' .; ::s :9 "' u ~ \.,J +" \0 1.5 1 0.5 ... • • 0 ••• • • • . ~ • .•. ·~ • • • ~ p 20 • • 40 60 80 • 100 ~ • -0.5 • • • • • • • • • -1 Minute Ventilation (Umin) Figure 123. Residuals of oxygen consumption from regression of oxygen consumption on minute ventilation. • • 1: 0 0.8 0.6 • • • 0.4 • 0.2 • • • • • • • • .... c 0 ·e d -0.2 "' •• • • • • • ....... -.. • - • J • 0.5 , 1 1.5 2 2.5 I ..... • • • co ::, -0.4 -0 ·.;; • .... • ... 0:: -0.6 • • w -0.8 Vl 0 -1 • -1.2 -1.4 Tidal Volume (L) Figure 124. Residuals from linear regression of oxygen consumption on tidal volume. \.,.) VI .... 7 • 6 • •• 5 , . u • u ... ~ • u 4 E , ~ ,., .. r:: -. .Q • ] 3 ca .c • >( IJ.:l 2 • .... 0+--------.---------,---------,-------,-------....--------r-------l 0 10 20 30 40 Respiratory Rate (breaths/min) Figure 125. Exhalation time and respiratory rate calibration data. 50 60 70 2.5 2 1.5 • 1 •• • "' 0.5 ca :::l "O ·;;; • Ill 0 ~ • • 6 7 8 w \J\ -0.5 N • •• •• • • • _, • • • • • _, .5 • • -2 Respiratory Period (sec) Figure 126. Exhalation time residuals from linear regression on the calibration data. Appendix C Data 353 Table 20. Subject 001 V 0 2max test. Time 0 2 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 17.96 2.06 47.6 1.29 1.53 16.68 0:01 :07 17.87 2.13 54.26 1.26 1.8 19.57 0:01 :37 17.02 2.29 55.94 1.36 2.43 26.44 0:02:08 16.7 2.4 64.54 1.65 3.05 33.11 0:02 :38 16.71 2.5 62.49 1.52 2.93 31.83 0:03:09 16.74 2.52 67.06 1.68 3.11 33.8 0:03:40 16.86 2 .57 70.09 1.71 3.13 34.05 0:04:10 16.94 2.54 76.12 1.65 3.34 36.26 0:04:41 17.12 2.46 79.39 1.62 3.31 36.01 0:05:11 17.29 2.42 84.62 1.73 3.36 36.57 0:05:43 17.29 2.44 89.85 1.76 3.57 38.78 0:06:13 17.3 2.47 101.4 1.78 4 43.5 0:06:44 17.36 2 .44 105.2 1.88 4.08 44.34 0:07:15 17.34 2.45 110.21 1.87 4.29 46.67 0:07:46 17.43 2.38 116.33 1.79 4.42 48.07 0:08:17 17.51 2.31 118.56 1.77 4.41 47.9 0:08:47 17.37 2.43 113.77 1.75 4.4 47.85 0:09:18 17.29 2.53 65.02 1.3 2.57 27.89 0:09:50 17.07 2.68 12.66 0.28 0.53 5.76 354 Table 21. Sub· ~ect 002 V 02max test. Time 02 h:m:s CO2 Ve Vr Vo2 Vo2 0:00:35 % % (Umin) (L) (Umin) 16.91 (mUkg/min) 0:01:06 2.53 26.69 0.61 1.18 20.33 0:01:38 17.12 2.59 25.46 0.5 1.05 18.16 0:02:08 16.89 2.58 27.24 0.76 1.21 20.8 0:02:39 16.79 2.57 29.45 0.76 1.34 23.16 0:03:10 16.53 2.68 27.09 0.54 1.32 22.69 0:03:41 16.48 2.72 28.43 0.73 1.4 24.12 0:04:12 16.37 2.8 29.89 0.75 1.51 25.96 0:04:42 16.54 2.74 37.5 0.6 1.81 31.24 0:05:14 15.97 2.9 32.24 0.85 1.78 30.63 0:05:44 16.44 2.83 33.76 0.79 1.67 28.73 0:06:14 16.53 2.87 33.66 0.99 1.62 27.9 0:06:45 16.5 2.91 35.03 1.17 1.69 29.21 0:07:16 16.7 2.87 35.78 0.94 1.65 28.4 0:07:47 16.61 2.89 37.1 0.9 1.74 30.08 0:08:17 16.55 2.89 44.57 0.97 2.13 36.73 0:08:48 16.9 2.77 46.69 1.33 2.04 35.17 0:09:18 17.2 2.72 48.2 1.18 1.93 33.25 0:09:50 17.2 2.73 49.59 1.34 1.98 34.2 0:10:20 17.12 2.79 57.39 1.43 2.35 40.46 0:10:51 17.45 2.62 54.56 1.21 2.03 34.99 0:11 :21 17.45 2.59 67.26 1.46 2.5 43.15 0:11 :52 17.88 2.42 73.8 1.48 2.38 40.99 18.01 2.37 77.14 1.54 2.37 40.83 355 Table 22. Subject 023 V 02max test. Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 17.25 1.98 21.58 0.36 0.89 19.02 0:01 :06 16.99 2.11 25.21 0.35 1.12 23.76 0:01 :37 16.58 2.3 22.44 0.56 1.1 23.43 0:02:08 16.58 2.36 24.16 0.89 1.18 25.1 0:02:38 16.65 2.39 28 .13 0.69 1.35 28.64 0:03:09 16.78 2.38 27 .57 0.71 1.28 27.15 0:03:40 16.72 2.41 28.14 0.78 1.32 28.1 1 0:04:11 16.77 2 .45 28.86 0.96 1.33 28.38 0:04:41 16.91 2.44 30.18 0.75 1.34 28.53 0:05:13 16.83 2.45 33.54 0.96 1.52 32.42 0:05:43 17.09 2.39 37.69 0.84 1.59 33.93 0:06:14 17.14 2.4 44.55 1.31 1.86 39.48 0:06:44 17.39 2.33 44.93 1.55 1.74 36.94 0:07:15 17.5 2.3 45.2 1.29 1.69 35.92 0:07:46 17.49 2.31 46.04 1.32 1.73 36.74 0:08:17 17.54 2.27 49.54 1.21 1.83 38.99 0:08:47 17.73 2.16 59.36 1.65 2.06 43.92 0:09:18 18.04 2.06 63.47 1.51 1.98 42.08 0:09:49 18.13 2.01 66.87 1.63 2.02 42.91 0:10:19 18.2 1.96 65.29 1.42 1.92 40.92 356 Table 23. Subject 145 V 0 2max test. Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 17.04 2.5 42.81 0.81 1.83 19.87 0:01:06 16.71 2.56 48.12 1.34 2.24 24.4 0:01:37 16.81 2.55 53.31 1.11 2.42 26.3 0:02:08 16.87 2.6 37.12 0.93 1.65 17.96 0:02:39 16.99 2.61 51.62 1.36 2.22 24.13 0:03:09 17.52 2.53 56.42 1.06 2.06 22.36 0:03:40 17.53 2.42 64.76 1.38 2.38 25.83 0:04:11 17.48 2.5 69.83 1.55 2.59 28.13 0:04:42 17.53 2.52 79.25 1.76 2.89 31.36 0:05:12 17.94 2.41 68.27 1.29 2.15 23.37 0:05:43 17.24 2.68 79.16 1.93 3.14 34.13 0:06:14 17.79 2.46 82.78 1.69 2.76 29.98 0:06:45 17.65 2.58 91.57 1.87 3.18 34.59 0:07:16 17.82 2.53 104.17 2.08 3.41 37.09 0:07:46 18.14 2.42 108.06 2.16 3.13 33.98 0:08:17 18.2 2.36 113.63 2.14 3.22 35.03 0:08:48 18.28 2.3 126.31 2.22 3.48 37.85 0:09:19 18.51 2.17 127.64 2.24 3.19 34.68 0:09:50 18.42 2.21 135.38 2.33 3.51 38.21 0:10:20 18.51 2.16 133.61 2.23 3.33 36.18 357 Table 24. Subject 173 V 0 2max test. Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 18.07 1.92 25.65 1.28 0.8 10.67 0:01 :06 17.13 2.26 26.82 1.03 1.13 15.08 0:01 :38 16.16 2.42 41 .6 1.39 2.25 29.96 0:02:08 16.56 2.39 44.09 1.42 2.16 28.86 0:02:38 16.67 2.49 50.86 1.7 2.41 32.15 0:03:10 16.86 2.51 50.92 1.76 2.28 30.45 0:03:40 16.72 2.62 53.84 1.86 2.5 33.27 0:04:11 16.83 2.64 55.72 1.8 2.5 33.39 0:04:41 16.94 2.6 57.72 1.86 2.52 33.62 0:05:12 17.06 2.6 60.3 1.88 2.54 33.85 0:05:43 17.07 2.64 63.75 1.99 2.67 35.62 0:06:14 17.27 2.73 68.35 2.14 2.68 35.73 0:06:45 17.31 2.78 72.03 2.18 2.77 36.97 0:07:16 17.37 2.76 71.08 1.97 2.69 35.84 0:07:48 17.41 2.73 74.46 2.19 2.79 37.15 0:08:18 17.43 2.71 77.5 2.35 2.88 38.43 0:08:48 17.49 2.69 79.39 2.34 2.9 38.64 0:09:20 17.45 2.72 80.36 2.36 2.97 39.56 0:09:50 17.48 2.71 82.79 2.44 3.03 40.35 0:10:21 17.56 2.7 84.39 2.34 3.01 40.08 0:10:52 17.65 2.63 88.96 2.28 3.07 40.99 0:11 :22 17.79 2.56 95.99 2.29 3.17 42.29 358 Table 25. Subject 214 V02max test. Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 18.65 2 11.79 0.84 0.28 3.62 0:01 :06 17.88 2.41 12.29 0.82 0.4 5.15 0:01 :37 17.52 2.54 14.18 0.75 0.52 6.72 0:02:08 17.36 2.61 16.85 0.84 0.65 8.39 0:02:39 17.26 2.74 32.6 0.84 1.28 16.6 0:03:09 16.16 3.38 36.29 1.13 1.87 24.25 0:03:40 16.18 3.42 53.42 1.78 2.73 35.44 0:04:11 16.2 3.62 52.95 2.21 2.66 34.55 0:04:42 15.74 3.9 56.06 2.8 3.1 40.27 0:05:13 16 3.86 63.63 2.65 3.32 43.06 0:05:44 16.15 3.82 67.3 3.06 3.39 43.97 0:06:14 16.35 3.71 66.53 2.15 3.2 41.53 0:06:44 16.16 3.79 71.48 2.75 3.6 46.65 0:07:15 16.23 3.71 72.54 2.9 3.6 46.75 0:07:46 16.12 3.8 73.47 2.62 3.74 48.5 0:08:17 16.12 3.86 75.34 2.9 3.82 49.53 0:08:48 16.15 3.89 77.54 2.77 3.9 50.53 0:09:18 16.38 3.77 76.46 2.94 3.64 47.23 0:09:49 16.26 3.84 79.32 2.64 3.89 50.44 0:10:20 16.48 3.76 96.9 3.13 4.5 58.37 0:10:51 16.62 3.79 111.61 2.79 4.97 64.5 0:11 :22 16.97 3.63 116.83 3.16 4.74 61.52 0:11 :53 17.14 3.53 117.12 2.93 4.53 58.72 0:12:23 17.09 3.53 123.15 2.8 4.83 62.67 0:12:54 17.28 3.4 123.26 2.8 4.59 59.53 0:13:25 17.39 3.34 132.32 2.5 4.77 61.83 0:13:55 17.51 3.21 123.39 2.37 4.3 55.72 0:14:26 17.57 3.18 19.3 0.41 0.66 8.54 359 Table 26. Subject 221 V 02rnax test. Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:36 15.35 3.13 35.06 0.95 2.19 29.17 0:01 :07 15.5 3.12 39.81 1 2.41 32.14 0:01 :37 15.28 3.31 46.95 1.47 2.95 39.32 0:02:08 15.68 3.37 53.35 1.44 3.07 40.94 0:02:38 16.01 3.27 51 .33 1.71 2.75 36.72 0:03:09 15.99 3.33 58.58 1.15 3.15 41.98 0:03:40 15.77 3.4 60.49 1.14 3.41 45.42 0:04:12 16.19 3.32 70.09 1.75 3.59 47.83 0:04:42 16.42 3.22 76.39 2.06 3.72 49.54 0:05:13 16.83 3.08 73.94 1.95 3.23 43.11 0:05:44 16.71 3.11 78.38 2.12 3.55 47.29 0:06:14 16.64 3.1 72.51 1.65 3.34 44.59 0:06:45 16.63 3.08 84.36 2.16 3.91 52.14 0:07:16 16.99 2.94 92.87 1.98 3.91 52.14 0:07:47 16.91 2.98 99.14 2.42 4.26 56.81 0:08:17 16.86 3.02 98.28 2.05 4.28 57.07 0:08:49 17.11 2.95 102.85 2.24 4.17 55.67 0:09:19 17.12 2.91 103.03 1.54 4.17 55.64 0:09:50 16.43 3.21 114.77 2.67 5.56 74.2 0:10:21 17.32 2.85 115.57 2.46 4.42 58.94 0:10:51 17.23 2.85 116.62 2.12 4.58 61.1 0:11 :22 17.33 2.77 120.39 2.74 4.61 61.45 0:11 :53 17.43 2.69 126.5 2.69 4.7 62.72 0:12:23 17.47 2.64 123.06 2.56 4.54 60.53 360 Table 27. Subject 224 V 02max test. Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 16.67 2.72 36.4 0.93 1.7 28.35 0:01 :06 16.87 2.49 37.41 0.85 1.68 28 0:01:37 16.55 2.49 41.08 0.84 2.01 33.44 0:02:08 16.33 2.53 43.72 0.93 2.26 37.61 0:02:38 16.41 2.58 48.18 1.12 2.43 40.53 0:03:10 16.63 2.61 50.64 1.08 2.41 40.12 0:03:40 16.77 2.59 47.59 0.95 2.18 36.36 0:04:11 16.37 2.71 52.16 0.84 2.64 43.94 0:04:41 16.1 2.82 57.09 1.27 3.07 51.12 0:05:12 16.68 2.68 57.55 1.22 2.69 44.86 0:05:43 16.85 2.6 60.33 1.28 2.7 45.06 0:06:14 16.9 2.57 60.68 1.21 2.68 44.72 0:06:44 16.91 2.57 57.1 0.98 2.52 42.02 0:07:15 16.7 2.64 62.71 1.28 2.92 48.71 0:07:46 16.85 2.59 61.62 0.98 2.76 46.01 0:08:17 16.56 2.69 70.76 1.31 3.42 56.93 0:08:47 16.8 2.66 76.25 1.11 3.45 57.5 0:09:18 16.97 2.61 75.96 1.43 3.29 54.77 0:09:50 17.1 2.56 77.32 1.52 3.23 53.75 0:10:20 17.14 2.53 79.69 1.48 3.3 54.93 361 I... Table 28. Subject 230 V 02rnax test. Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 16.72 2.29 21 .34 0.51 1.01 15.89 0:01 :06 16.25 2.43 29.09 0.57 1.54 24.22 0:01 :37 15.64 2.62 26.56 0.63 1.59 25.11 0:02:08 15.03 2.68 40.59 0.88 2.74 43.19 0:02:39 15.05 2.77 39.83 1.14 2.67 42.06 0:03:10 15.65 2.87 40.9 1.05 2.42 38.13 0:03:40 15.89 3.04 48.27 1.18 2.69 42.38 0:04:11 16.43 2.89 47.73 0.92 2.35 37.06 0:04:42 16.6 2.82 51.08 1.19 2.42 38.13 0:05:12 16.76 2.84 53.98 1 2.44 38.48 0:05:43 16.92 2.77 60.35 1.28 2.63 41.35 0:06:14 16.99 2.79 65.08 1.45 2.77 43.58 0:06:44 17.18 2.7 64.57 1.5 2.61 41.06 0:07:15 17.1 2.77 72.75 1.62 2.99 47.14 0:07:46 17.48 2.58 69.5 1.29 2.57 40.42 0:08:17 17.52 2.49 76.4 1.56 2.8 44.08 0:08:48 17.43 2.49 69.63 1.42 2.63 41.43 0:09:19 17.22 2.58 80.55 1.58 3.23 50.89 362 Table 29. Subject 231 V 02rnax test. Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 17.29 2.16 21 .86 0.5 0.88 14.29 0:01 :06 16.54 2.41 28.35 0.77 1.4 22.61 0:01 :37 16.02 2.44 29.92 0.75 1.67 27.03 0:02:08 15.93 2.52 35.73 0.94 2.02 32.76 0:02:39 16.13 2.56 34.79 0.89 1.88 30.46 0:03:10 16.01 2.68 39.76 1.17 2.19 35.54 0:03:40 16.23 2.72 37.98 0.88 1.99 32.2 0:04:11 16.28 2.7 40.49 1.19 2.09 33.92 0:04:42 16.3 2.7 38.93 0.97 2 32.49 0:05:12 16.39 2.7 42.51 1.04 2.14 34.67 0:05:44 16.44 2.69 45.78 1.2 2.28 36.91 0:06:14 16.49 2.72 49.17 1.26 2.41 39.02 0:06:46 16.55 2.72 48.58 1.35 2.35 38.06 0:07:16 16.66 2.7 52.77 1.43 2.48 40.18 0:07:46 16.86 2 .62 51.24 1.11 2.29 37.11 0:08:17 16.75 2.6 54.61 1.37 2.52 40.8 0:08:48 16.85 2.58 58.81 1.51 2.64 42.73 0:09:18 16.87 2.59 54.81 1.25 2.44 39.57 0:09:49 17.07 2.55 57.28 1.36 2.42 39.19 0:10:20 17.01 2.56 54.18 1.08 2.32 37.6 0:10:51 16.87 2.61 63.6 1.41 2.83 45.89 0:11 :22 17.33 2.44 61 .48 1.4 2.41 39.01 0:11 :52 17.3 2.44 64.47 1.43 2.55 41.36 0:12:23 17.31 2.43 65.04 1.41 2.56 41.57 0:12:54 17.42 2.43 67.34 1.37 2.56 41.52 0:1 3:25 17.52 2.39 66.21 1.38 2.44 39.56 363 Table 30. Subject 001 levels determination test. Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 16.22 2.53 26.99 1.04 1.43 15.54 O:D1:06 15.91 2.62 25.98 0.76 1.47 15.97 0:01 :37 15.58 2.73 30.33 0.72 1.83 19.94 0:02:08 16.18 2.63 29.86 0.85 1.59 17.28 0:02:39 16.38 2.61 29 0.97 1.47 15.98 0:03:10 16.49 2.59 31 .77 1.13 1.57 17.06 0:03:40 16.56 2.58 28.16 0.88 1.37 14.85 0:04:11 16.4 2.64 30.12 0.91 1.52 16.49 0:04:42 16.18 2.68 33.18 1.11 1.76 19.15 0:05:13 16.33 2.63 33.13 0.95 1.7 18.46 0:05:44 16.19 2.7 33.67 1.09 1.78 19.35 0:06:15 16.31 2.64 36.33 1.14 1.87 20.36 0:06:45 16.32 2.67 38.52 1.38 1.97 21.46 0:07:16 16.45 2.7 39.24 1.15 1.94 21.12 0:07:47 16.4 2.71 41.79 0.97 2.1 22.78 0:08:17 16.34 2.68 39.48 1.27 2.02 21.93 0:08:48 16.06 2.77 42.21 1.28 2.29 24.92 0:09:19 16.11 2.78 45.14 1.22 2.43 26.37 0:09:50 16.31 2.72 49.73 1.18 2.55 27.72 0:10:21 16.54 2.64 57.03 1.5 2.77 30.1 0:10:51 16.68 2.58 58.23 1.53 2.74 29.77 0:11 :22 16.72 2.61 59.41 1.49 2.75 29.94 0:11 :53 16.69 2.69 61 .25 1.53 2.85 31.03 0:12:23 16.69 2.7 57.54 1.6 2.68 29.1 0:12:54 16.5 2.78 60.45 1.41 2.94 32.01 0:13:25 16.62 2.74 62.68 1.53 2.97 32.25 0:13:56 16.49 2.83 65.68 1.73 3.21 34.84 0:14:27 16.7 2.76 67.22 1.68 3.11 33.85 0:14:57 16.72 2.72 68.24 1.66 3.14 34.16 0:15:28 16.88 2.83 76.71 1.78 3.36 36.48 0:15:59 17.08 2.77 82.52 1.65 3.42 37.18 0:16:30 17.2 2.72 88.16 1.73 3.53 38.41 0:17:01 17.15 2.73 94.64 1.79 3.85 41.82 0:17:32 17.29 2.66 94.11 1.36 3.67 39.91 0:18:02 16.94 2.81 102.5 1.8 4.41 47.98 0:18:33 17.29 2.72 109 1.95 4.25 46.16 0:19:04 17.32 2.72 104.7 1.87 4.04 43.9 0:19:34 17.07 2.83 107.9 1.83 4.47 48.57 0:20:05 17.39 2.65 45 0.68 1.7 18.5 0:20:36 17.22 2.75 9.56 0.12 0.38 4.13 364 Table 31. Subject 002 levels determination test. Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:36 17.65 1.85 17.28 0.38 0.63 10.91 0:01 :07 16.92 2.3 16.79 0.31 0.75 12.96 0:01:37 16.39 2 .48 17.88 0.66 0.91 15.71 0:02:08 16.04 2.66 16.57 0.35 0.91 15.67 0:02:39 15.86 2.71 17.24 0.39 0.98 16.94 0:03:10 15.68 2.79 16.63 0.45 0.98 16.93 0:03:41 15.77 2.81 17.46 0.34 1.01 17.43 0:04:11 15.89 2.79 18.54 0.6 1.05 18.03 0:04:42 16.15 2.66 19.45 0.63 1.04 17.94 0:05:13 16.37 2.61 18.55 0.48 0.94 16.28 0:05:43 16.37 2.64 19.78 0.76 17.29 0:06:14 16.3 2.63 20.7 0.67 1.07 18.44 0:06:45 16.49 2.52 20.56 0.64 1.02 17.56 0:07:16 16.34 2.63 22.39 0.72 1.15 19.76 0:07:47 16.52 2.6 23.12 0.86 1.13 19.52 0:08:18 16.69 2.52 21.31 0.56 17.29 0:08:49 16.71 2.61 23.84 0.61 1.11 19.11 0:09:19 16.98 2.53 23.37 0.51 1.01 17.48 0:09:50 16.75 2.54 23.12 0.66 1.07 18.45 0:10:21 16.68 2.51 19.23 0.62 0.91 15.65 0:10:51 16.43 2.57 22.05 0.4 1.11 19.1 0:11 :22 16.37 2.57 19.75 0.76 1.01 17.35 0:11 :53 16.32 2.64 22.23 0.58 1.14 19.68 0:12:24 16.31 2.66 22.55 0.56 1.16 20.02 0:12:55 16.44 2.67 20.28 0.48 1.01 17.39 0:13:25 16.44 2.66 18.26 0.79 0.91 15.67 0:13:56 16.17 2.74 21 .15 0.56 1.12 19.35 0:14:27 16.13 2.76 18.81 0.52 1.01 17.35 0:14:58 16.23 2.76 22.19 0.89 1.16 19.95 0:15:28 16.53 2.66 23.66 0.58 1.15 19.86 0:15:59 16.66 2.58 22.65 0.76 1.07 18.44 0:16:30 16.76 2.58 21.86 0.64 1.01 17.34 0:17:01 16.54 2.65 22.84 0.63 1.11 19.15 0:17:32 16.69 2.62 19.93 0.37 0.93 16.07 0:18:03 16.48 2.56 29.53 0.66 1.46 25.23 0:18:33 16.44 2.58 26.25 0.73 1.31 22.65 0:19:05 16.58 2.61 25.82 0.68 1.24 21.45 0:19:35 16.44 2.65 30.41 0.53 1.52 26.17 0:20:06 16.28 2.67 32.96 0.87 1.71 29.48 0:20:36 16.43 2.69 34.52 1.02 1.72 29.65 0:21 :07 16.44 2.72 35.54 0.87 1.76 30.4 365 Table 31. Subject 002 levels determination test (cont.). Time 0 2 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:21 :38 16.57 2.69 40.3 1.09 1.94 33.4 0:22:09 16.84 2.6 36.65 0.99 1.65 28.43 0 :22:40 16.71 2.6 36.88 0.7 1.72 29.58 0:23:10 16.37 2.67 37.68 0.88 1.91 32.89 0:23:41 16.44 2.66 38.56 1.04 1.92 33.1 0:24:12 16.64 2.58 37.7 0.99 1.79 30.88 0:24:43 16.8 2.51 36.64 0.85 1.67 28.85 0:25:13 16.65 2.56 36.65 0.96 1.74 29.97 0:25:44 16.48 2.58 31.56 0.79 1.57 26.99 0:26:15 16.37 2.64 31.47 0.75 1.6 27.58 0:26:46 16.24 2 .67 30.65 0.67 1.6 27.66 0:27:17 16.16 2.73 28.78 0.6 1.53 26.38 0 :27:48 16.72 2 .46 9.92 0.16 0.46 8.01 0:28:19 16.94 2 .31 9.75 0.14 0.43 7.48 0:00:36 20.08 0.43 19.05 0.73 0.18 3.17 0:01 :06 17.41 1.88 16.2 0.54 0.64 11.06 0:01 :37 16.91 2.25 16.58 0.79 0.75 12.85 0:02:08 16.23 2.45 18.74 0.94 0.99 17.15 0:02:38 16.07 2.5 16.91 0.48 0.93 16.03 0:03:10 16.06 2.48 15.86 0.41 0.87 15.07 0:03:40 15.97 2.51 15.51 0.4 0.87 15.04 0:04:11 15.91 2.54 15.53 0.52 0.88 15.22 0:04:42 16.12 2 .5 15.23 0.69 0.83 14.26 0 :05:12 16.18 2.48 13.34 0.78 0.71 12.33 0:05:43 16.22 2.5 14.03 0.56 0.74 12.84 0:06:14 16.15 2.53 13.81 0.34 0.74 12.81 0:06:44 16.17 2.53 14.05 0.56 0.75 12.98 366 Table 32. Su . . bJect 023 levels detenrunation test. Time h:m:s 0:00:35 0:01:06 0:01 :37 0:02:07 0:02:38 0:03:09 0:03:40 0:04:11 0:04:42 0:05:13 0:05:44 0:06:15 0:06:45 0:07:16 0:07:47 0:08:17 0:08:48 0:09:19 0:09:49 0:10:20 0:10:51 0:11 :22 0:11 :53 0:12:24 0:12:55 0:13:25 0:13:56 0:14:26 0:14:57 0:15:28 0:16:oo 0:16:30 0:11:oo 0:17:31 0:10:02 0:18:32 0:19:03 0:19:34 0:20:05 0:20:36 0:21:07 0:21:37 0:22:09 0:22:39 0:23:10 17.44 17.08 16.89 16.64 16.65 16.61 16.52 16.6 16.72 16.79 16.72 16.78 16.52 16.11 16.31 16.74 16.69 16.58 16.76 16.86 16.82 16.95 17.07 17.01 16.97 16.85 16.91 16.74 16.76 16.76 16.73 16.63 16.55 16.44 16.48 16.69 16.72 16.76 16.7 16.67 16.44 16.57 16.8 16.83 16.95 2.04 2.22 2.3 2.35 2.33 2.36 2.38 2.35 2.34 2.33 2.26 2.28 2.41 2.59 2.47 2.29 2.29 2.32 Ve Vr (Umin) (L) 12.97 0.38 13.55 0.35 13.14 0.36 14.51 0.37 15.59 0.28 12.96 0.29 15.1 0.41 14.67 0.37 14.91 0.44 15.24 0.42 15.67 0.41 13.2 0.29 13.92 0.31 14.68 0.37 17.19 0.45 15.92 0.36 16.02 0.44 16.06 0.41 2.28 16.37 0.41 2.27 2.29 2.24 2.24 16.43 0.42 18.79 0.65 18.1 0.52 16.17 0.38 2.27 18.29 0.47 2.25 17.79 0.41 2.27 18.54 0.34 2.24 17.38 0.39 2.32 17 .89 0.47 2.3 19.43 0.45 2.28 19.8 0.5 2.35 19.16 0.43 2.36 18.99 0.51 2.35 20.79 0.53 2.38 21.69 0.53 2.39 22.31 0.47 2.36 21.72 0.57 2.39 24.77 0.67 2.36 21.85 0.55 2.36 22.82 0.56 2.37 23.13 0.46 2.44 25.1 0.47 2.38 26.04 0.61 2.36 28.15 0.83 2.35 29.12 0.97 2.35 26.68 0.74 Vo2 Vo2 (Umin) (mUkg/min) 0.5 10.72 0.58 12.37 0.59 12.59 0.7 0.75 0.63 0.75 0.71 0.7 0.7 0.74 0.61 0.69 0.8 0.89 0.75 0.76 0.79 o.77 0.75 0.86 0.8 0.7 0.8 0.79 0.85 0.78 0.84 0.91 0.93 0.9 0.92 1.03 1.1 1.11 1.03 1.16 1.02 1.08 1.1 1.27 1.28 1.3 1.33 1.18 367 14.85 15.93 13.37 15.93 15.19 14.95 14.99 15.8 13.07 14.66 16.93 19 15.91 16.25 16.72 16.31 15.93 18.39 17.11 14.8 16.99 16.72 18.01 16.65 17.86 19.33 19.72 19.14 19.49 21.82 23.33 23.72 21.95 24.75 21.64 23 23.49 26,94 27,13 27.62 28.35 25.1 Table 32 Sub . · ~ect 023 levels detennination test (cont.). Time 02 h:m:s % 0:23:40 0:24:12 0:24:42 0:25:13 0:25:43 0:26:14 0:26:45 0:27:16 0:27:47 0:28:18 0:28:49 0:29:20 0:29:50 0:30:22 0:00:36 0:01 :06 0:01 :37 0:02:08 0:02:38 0:03:0g 0:03:40 0:04:11 0:04:42 0:05:12 0:05:43 0:06:14 0:06:45 0:07:15 0:00:36 0:01:07 0:01:37 0:02:08 0:02:39 0:03:10 0:03:40 0:04:11 0:04:42 0:05:1 2 o:05:43 0:06:14 0:06:45 0:07:16 0:07:47 16.65 16.65 16.8 16.87 16.71 16.47 16.86 16.8 16.98 17.04 17.03 16.82 16.73 16.95 18.18 17.6 17.39 16.89 16.54 16.3 16.37 16.55 16.55 16.95 16.83 17.01 16.95 16.86 18.19 17.46 17.23 17.1 16.9 16.96 16.86 16.83 16.92 17.07 17.02 16.92 16.81 16.76 16.61 VE (Umin) 26.71 Vr (L) 0.67 Vo2 Vo2 % (Umin) (mUkg/min) 1.27 27.06 2.51 2.49 28.81 0.82 1.37 29.19 2.44 31.86 1.06 2.39 29.26 0.98 1.46 31.13 1.32 2.44 28.12 1.08 1.32 2.51 32.95 1.22 1.64 2.39 31.53 0.88 2.46 34.34 0.95 1.43 1.57 2.38 32.9 0.89 2.35 32.99 1.22 1.44 1.42 1.12 2.36 25.97 0.87 1.08 2.43 23.61 0.81 2.37 24.89 0.58 1.17 0.78 2.25 1.45 1.72 1.79 1.99 2.15 2.23 2.31 2.36 2.47 2.35 2.42 2.36 2.41 2.46 1.44 1.86 2.02 2.06 2.14 2.11 2.12 2.13 2.1 2.08 2.09 2.12 2.12 2.13 2.17 17.44 0.44 10.74 0.29 0.33 8.92 0.16 0.34 15.87 0.33 0.64 18.17 0.38 0.83 22.71 0.57 1.13 26.69 0.95 1.41 31 .8 0.96 1.64 29.86 0.96 1.47 38.15 1.36 1.87 35.15 0.93 1.55 37.78 1.45 1.72 36.09 1.16 1.57 36.94 1.27 1.63 39.11 1.22 1.76 8.15 0.14 0.25 8.3 0.12 0.32 9.27 0.17 0.38 9.5 0.23 0.41 8.78 0.18 0.4 10.94 0.23 0.49 10.09 0.14 0.46 10.59 0.23 0.49 11.3 0.36 0.51 10.03 0.16 0.44 10.31 0.17 12.19 0.32 12.44 0.38 12.76 0.38 12.97 0.38 0.45 0.55 0.58 0.6 0.63 368 28.1 28.14 34.89 30.39 33.5 30.64 30.26 23.83 22.91 24.85 16.5 7.09 7.14 13.54 17.74 24.11 29.98 34.97 31.24 39.69 33.03 36.59 33.35 34.64 37.43 5.36 6.89 8.19 8.71 8.48 10.42 9.87 10.43 10.89 9.26 9.64 11.72 12.31 12.79 13.5 Table 33. Subject 145 levels determination test. Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:36 18.1 2.18 21.05 0.48 0.63 7.14 0:01 :06 18.09 2.17 16.2 0.52 0.49 5.54 0:01:37 18.11 2.03 19.3 0.69 0.59 6.6 0:02:08 18.28 2.02 32.96 0.8 0.93 10.51 0:02:39 17.85 2.32 35.23 1.01 1.16 13.09 0:03:09 18.21 2.27 29.82 0.62 0.85 9.59 0:03:41 17.72 2.33 29.37 0.68 1.01 11.45 0:04:11 17.47 2.36 27.48 0.57 1.03 11.65 0:04:43 17.36 2.31 26.31 0.39 1.03 11.61 0:05:13 17.14 2.35 27.22 0.5 1.14 12.85 0:05:43 16.98 2.41 33.1 0.61 1.45 16.31 0:06:14 17.53 2.35 29.88 0.55 1.1 12.43 0:06:45 17.58 2.32 32.06 0.51 1.17 13.15 0:07:16 17.51 2.27 30.19 0.43 1.13 12.71 0:07:47 17.51 2.3 27.58 0.45 1.03 11.58 0:08:17 17.04 2.43 32.69 0.73 1.4 15.8 0:08:49 17.39 2.42 34.64 0.65 1.33 15.03 0:09:19 17.82 2.3 30.4 0.49 1.01 11.42 0:09:50 17.3 2.4 29.91 0.62 1.19 13.4 0:10:20 17.16 2.48 31.99 0.68 1.32 14.88 0:10:51 17.25 2.48 30.73 0.56 1.23 13.91 0:11 :22 17.37 2.39 32.07 0.65 1.24 14.03 0:11 :53 17.46 2.35 35.5 0.67 1.34 15.13 0:12:24 17.4 2.41 40.78 0.91 1.57 17.67 0:12:55 17.62 2.38 41.42 1.15 1.47 16.64 0:13:25 17.75 41.86 0.89 1.43 16.09 2.37 0:13:56 17.75 48.24 1.07 1.65 18.58 2.34 0:14:27 18.11 0.79 1.26 14.21 2.19 42.05 17.83 0:14:58 17.4 2.35 41.09 0.89 1.58 0:15:28 0.75 1.5 16.98 17.33 2.41 38.32 20.05 0:15:59 0.89 1.78 17.14 2.46 42.8 21.5 0:16:30 17.28 2.45 47.91 0.86 1.91 0.92 1.64 18.5 0:17:00 17.44 2.38 43.28 20.5 0:17:31 16.98 2.52 41.88 0.91 1.82 1.06 2.09 23.63 0:18:02 16.95 2.56 47.91 17.27 0.92 1.53 0:18:33 17.7 2.34 44.01 18.9 0:19:04 17.62 2.36 46.84 1 1.67 0.96 1.57 17.67 0:19:35 17.64 2.35 44.1 18.84 0.78 1.67 0:20:05 17.42 2.42 43.85 20.53 1.11 1.82 0:20:36 17.41 2.41 47.53 21.67 1.19 1.92 0:21:06 17.54 2.36 52.25 24.79 0:21:37 17.66 2.32 62.34 1.09 2.2 20.98 0:22:08 17.75 2.33 54.49 1.11 1.86 2.47 27.83 0:22:39 17.45 2.39 65.21 1.42 19.76 0:23:09 17.99 2.24 55.88 1.1 1.75 24,21 0:23:40 17.48 2.4 57.39 1.2 2.15 369 Table 33. Subject 145 levels determination test (cont.). Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:24:11 17.37 2.42 57.06 1.36 2.21 24.96 0:24:42 17.5 2.42 58.25 1.46 2.16 24.37 0:25:13 17.32 2.48 54.08 1.2 2.12 23.94 0:25:43 17.44 2.44 63.01 1.34 2.38 26.87 0:26:14 18 2.26 62.97 1.23 1.96 22.1 0:26:45 17.8 2.28 66.22 1.54 2.23 25.17 0:27:15 17.93 2.24 60.77 1.41 1.95 22.04 0:27:46 17.55 2 .34 69.41 1.42 2.54 28.67 0:28:17 18.07 2.21 67.61 1.33 2.06 23.21 0:28:48 18.01 2.2 70.39 1.44 2.19 24.75 0:29:18 17.93 2.19 53.85 1.22 1.73 19.56 0:29:49 17.03 2.45 73.54 1.75 3.15 35.58 0:30:20 17.96 2.29 95.52 1.87 3.02 34.12 0:30:51 18.39 2.15 98.05 1.85 2.6 29.35 0:31:22 18.31 2.14 90.45 1.64 2.49 28.09 0 :31:53 17.93 2.28 100.5 1.97 3.21 36.24 0:32:24 18.33 2.19 119.8 2.49 3.25 36.69 0:32:55 18.59 2.06 106.9 2.06 2.59 29.28 0:33:25 18.22 2.16 95.53 1.84 2.74 30.89 0:33:56 18.04 2.25 107 2.23 3.29 37.1 0:34:27 18.33 2.13 109.8 2.11 3 33.83 0:34:57 18.33 2.1 54.66 1.27 1.5 16.89 0:35:29 17.92 11.72 0.24 0.38 4.28 2.2 0:35:59 18.13 12.64 0.29 0.38 4.28 2.06 0:36:29 18.01 13.31 0.34 0.42 4.71 2.15 0:37:00 17.98 12.66 0.28 0.4 4.52 2.15 370 Table 34. Subject 173 levels determination teSl. Time 02 Ve Vr Vo2 Vo2 CO2 (mUkg/min) h:m:s % % (Umin) (L) (Umin) 0:00:35 0.67 0.87 11.64 17.97 2.12 27.39 13.14 0:01 :06 0.83 0.99 17.43 2.34 25.86 12.28 0:01:37 0.87 0.92 17.09 2.46 21.83 14.34 0:02:09 0.84 1.08 16.82 2.51 23.65 14.33 0:02:40 16.75 2.53 23.22 0.75 1.07 1.13 15.04 0:03:10 16.74 2.57 24.4 0.84 13.34 1 0:03:40 16.99 2.48 23.06 0.89 11.91 0:04:11 17 2.49 20.7 0.65 0.89 11.22 0:04:42 17.02 2.51 19.63 0.46 0.84 11.1 0:05:13 16.92 2.53 18.86 0.75 0.83 1.02 13.64 0:05:44 16.61 2.64 21.41 0.93 13.54 1.02 0:06:15 16.79 2.61 22.27 0.8 13.24 0.99 0:06:46 17.06 2.55 23.45 0.87 11.91 0:07:16 17.2 2.5 21.99 0.92 0.89 0.87 11.54 0:07:46 17.19 2.54 21.31 0.71 12.71 0:08:17 23.47 0.78 0.95 17.2 2.49 12.94 0:08:48 17.14 23.49 1.12 0.97 2.53 0.97 12.96 0:09:19 17.09 2.61 23.31 0.93 15.25 0:09:51 25.2 0.93 1.14 16.79 2.66 17.22 0:10:22 28.68 0.84 1.29 16.82 2.67 15.21 0:10:52 26.86 0.9 1.14 17.03 2.62 15.33 0:11 :22 27.05 0.9 1.15 17.03 2.61 14.72 0:11 :53 24.85 0.73 1.1 16.87 2.64 16.81 0:12:24 26.66 1.11 1.26 18.87 16.63 2.71 0:12:55 30.54 1.17 1.42 16.57 16.71 2.71 0:13:26 28.08 1.04 1.24 15.61 16.88 2.65 0:13:57 26.51 0.76 1.17 18.48 16.89 2.66 0:14:27 30.18 1.04 1.39 15.92 16.74 2.71 1.19 0:14:57 16.89 2.68 27.12 0.82 15.7 0:15:28 27.86 0.99 1.18 16.79 17.05 2.61 0:15:59 27.64 1.02 1.26 18.63 16.78 2.67 1.4 0:16:30 16.72 2.73 30.32 1.08 20.23 0:17:01 33.09 1.14 1.52 21.57 16.74 2.72 1.62 0:17:32 34.54 1.19 21.45 16.66 2.76 1.61 0:18:03 34.55 1.28 20.48 16.66 2.83 1.54 0:18:33 34.52 1.28 21.96 16.84 2.77 1.65 0:19:03 16.78 2.79 36.46 1.35 21.06 0:19:34 35.13 1.1 1.58 19.41 16.8 2.79 1.46 0:20:05 16.83 2.74 32.63 0.91 21.68 33.55 1.16 1.63 21.76 0:20:36 16.51 2.82 33.98 1.26 1.63 20.07 0:21 :07 16.54 2.86 1.51 0:21 :38 16.7 2.83 32.65 1.26 1.82 24,33 40.78 1.51 23,98 0 :00:36 16.83 2.7 1.8 0:01 :07 16.92 2.7 41.25 1.53 25,87 1.94 0:01 :38 16.89 2.75 44.18 1.58 371 Table 34. Subject 173 levels determination test (cont.). Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:02:08 16.95 2.74 46.49 1.66 2.01 26.74 0:02:38 16.89 2.8 53.48 1.84 2.34 31.19 0:03:09 17.22 2 .74 54.56 1.82 2.17 28.96 0:03:40 17.22 2.77 53.99 1.74 2.15 28.61 0:04:12 17.1 2.81 54.47 1.82 2.24 29.85 0:04:42 17.26 2.77 57.77 1.81 2.26 30.14 0:05:13 17.22 2.8 55.68 1.74 2.21 29.41 0:05:43 17.12 2.82 55.03 1.83 2.25 29.96 0:06:14 17.13 2.81 49.53 1.83 2.01 26.86 0:06:45 16.95 2.91 46.99 1.62 2.01 26.79 0:07:16 17.81 2.68 42.82 1.34 1.39 18.51 0:07:47 18.09 2.56 32.29 1.15 0.94 12.57 0:08:18 18.42 2.38 25.2 0.84 0.64 8.56 0:08:49 18.51 2.33 47.86 0.7 1.17 15.66 0:09:19 18.55 2.28 31.8 0.53 0.77 10.21 0:09:49 18.55 2.24 25.55 0.75 0.62 8.27 0:10:20 18.27 2.29 12.32 0.46 0.34 4.54 0:10:51 18.02 2.41 11.57 0.4 0.35 4.7 0:11 :22 17.73 2.49 15.2 0.37 0.52 6.89 0:11 :54 17.75 2.44 27.98 0.74 0.95 12.62 0:12:25 18.45 2 .13 26.53 0.95 0.69 9.14 0:12:54 17.86 2.4 35.65 1.32 1.16 15.49 0:13:25 17.17 2.56 43.45 1.45 1.77 23.67 0:13:56 17.09 2.54 48.86 1.48 2.05 27.27 0:14:26 17.12 2.55 55.68 1.64 2.31 30.79 0:14:57 17.28 2.56 60.46 1.78 2.39 31.83 0:15:29 17.17 2.64 64.37 1.84 2.62 34.89 0:16:00 17.4 2 .6 65.87 1.65 2.5 33.27 0:16:30 17.38 2.65 67.27 1.98 2.55 33.99 0:17:00 17.41 2.63 69 .23 2.1 2.6 34.71 0:17:31 17.43 2.62 69.93 2 2.61 34.83 0:18:02 17.4 2 .62 69.21 1.92 2.61 34.87 372 Table 35. Subject 214 levels determination test. Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 17.69 2.28 29.36 0.86 1.03 13.34 0:01 :06 17.17 2.63 28.82 1.07 1.17 15.22 0:01 :37 16.57 2.83 31.64 0.99 1.51 19.58 0:02:08 16.56 2.77 29.34 0.95 1.41 18.26 0:02:38 16.43 2.85 31.29 1.04 1.55 20.09 0:03:09 16.58 2.8 31.01 0.89 1.48 19.2 0:03:40 16.59 2.74 28.76 0.8 1.37 17.8 0:04:11 16.48 2.79 31.34 0.95 1.53 19.89 0:04:42 16.41 2.85 31.07 1.35 1.54 20.01 0:05:12 16.51 2.81 28.78 0.8 1.4 18.14 0:05:43 16.2 2.87 34.94 1.03 1.83 23.7 0:06:13 16.45 2.81 33.44 0.96 1.65 21.39 0:06:44 16.35 2.89 31.11 0.84 1.56 20.3 0:07:15 16.31 2.81 37.08 1.24 1.89 24.57 0:07:46 16.62 2.77 31.55 0.85 1.49 19.31 0:08:17 16.42 2.86 32.91 0.77 1.63 21.15 0:08:48 16.26 2.94 31.89 0.86 1.64 21.22 0:09:18 16.24 2.95 40.01 0.87 2.06 26.77 0:09:49 16.47 2.86 35.63 1.05 1.74 22.59 0:10:20 16.36 2 .91 38.48 1.13 1.93 25.03 0:10:51 16.46 2.87 34.46 1.01 1.69 21.92 0:11 :21 16.15 3 39.09 1.03 2.06 26.67 0:11 :52 16.41 2.92 35.64 0.99 1.76 22.89 0:12:23 16.38 2.93 35.73 0.85 1.78 23.11 0:12:54 16.27 2.95 32.42 1.41 1.66 21.5 0:13:25 15.81 3.1 30.94 1.24 1.75 22.71 0:13:56 15.84 3.05 38.52 1.38 2.17 28.2 0:14:26 16.22 3.01 38.96 1.5 2.01 26.13 0:14:57 16.33 2.99 36.01 1.03 1.81 23.5 0:15:28 16.05 3.09 31.84 1.06 1.71 22.15 0:15:59 15.4 3.29 32.85 0.94 2.01 26.13 0:16:29 15.6 3.24 34.81 1.51 2.05 26.61 0:17:00 15.76 3.22 35.96 2.05 26.56 0:17:31 15.99 3.13 41.87 1.1 2.27 29.49 0:18:02 16.27 3.08 36.68 1.15 1.86 24.17 0:18:32 15.63 3.37 34.15 1.63 1.99 25.75 0:19:03 15.58 3.4 41.47 1.38 2.43 31.58 0:19:34 15.81 3.31 38.29 1.28 2.15 27.84 0:20:05 15.95 3.26 43.23 2.16 2.35 30.52 0:20:35 16.02 3.24 39.02 1.39 2.09 27.14 0:21 :06 16.14 3.19 40.6 1.62 2.12 27.51 0:21 :37 16.11 3.15 45 1.29 2.37 30.75 0:22:07 16.14 3.14 43.2 1.6 2.26 29.3 0:22:38 16.31 3.16 40.9 1.36 2.05 26.58 0:23:09 16.17 3.11 49.3 1.97 2.57 33.32 0:23:40 16.68 2.93 54.23 0.9 2.5 32.39 373 Table 35. Subject 214 levels determination test (cont.). Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:24:11 16.25 3.09 49.14 1.36 2.51 32.57 0:24:41 16.39 3.02 56.21 1.87 2.78 36.1 0:25:12 16.52 2.94 54.71 2.1 2.63 34.09 0:25:43 16.24 3.16 55.11 1.97 2.82 36.52 0:26:14 16.32 3.14 57.11 2.38 2.86 37.1 0:26:45 16.4 3.14 66.28 2.21 3.26 42.22 0:27:16 16.47 3.1 68.52 2.74 3.31 42.93 0:27:46 16.35 3.2 69.58 2.9 3.45 44.73 0:28:17 16.24 3.25 71.94 2.88 3.66 47.41 0:28:48 16.2 3.26 77.42 3.52 3.97 51.5 0:29:18 16.35 3.19 76.39 2.31 3.79 49.12 0:29:49 16.31 3.24 75.94 2.53 3.79 49.22 0:30:21 16.29 3.25 79.68 2.75 4 51.9 0:30:51 16.4 3.21 81.77 2.92 4 51.89 0:31 :21 16.41 3.18 79.08 2.82 3.86 50.12 0:31 :52 16.32 3.23 81.86 2.92 4.08 52.95 0:32:23 16.57 3.13 80.7 2.6 3.79 49.18 0:32:53 16.46 3.16 83.07 3.32 4.01 52 0:33:24 16.49 3.14 81.12 3.12 3.89 50.45 0:33:55 16.51 3.08 80.09 2.76 3.83 49.63 0:34:26 16.58 3.04 80.44 2.51 3.79 49.14 0:34:56 16.65 3 74.88 3.12 3.47 44.99 0:35:27 16.36 3.09 72.54 2.59 3.6 46.74 0:35:58 16.39 3.09 75.1 2.5 3.7 48.01 0:36:29 16.61 2.95 74.77 2.77 3.5 45.45 0:37:00 16.68 2.88 69.64 2.58 3.22 41.7 0:37:31 16.35 2.97 66.89 2.57 3.35 43.49 0:38:01 16.08 3.08 65.47 1.77 3.49 45.28 374 Table 36. Subject 22 1 levels detennination test. Time 02 CO2 VE Vr Vo2 Vo2 h:rn:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:37 16.86 2.46 20.81 0.56 0.94 12.49 0:01:07 15.68 2.86 24.86 0.58 1.47 19.54 0:01 :37 15.29 2.91 23.76 0.53 1.51 20.17 0:02:08 15.33 2.95 24.97 0.42 1.58 21.02 0:02:39 15.31 2.93 25.96 0.84 1.65 21.95 0:03:10 15.81 2 .92 24.25 0.55 1.38 18.45 0:03:41 15.83 2.93 21.61 0.58 1.23 16.36 0:04:11 15.74 2.96 22.84 0.65 1.32 17.63 0:04:41 15.96 2.93 21.43 0.63 1.18 15.75 0:05:13 15.93 2.95 22.8 0.57 1.27 16.89 0:05:43 15.79 2.97 21.38 0.56 1.22 16.31 0:06:15 15.75 3 24.63 0.63 1.42 18.92 0:06:46 15.88 3 24.96 0.66 1.4 18.65 0:07:15 15.75 3.02 26.5 0.74 1.53 20.36 0:07:46 15.45 3.07 26.37 0.82 1.61 21.53 0:08:17 15.48 3.13 27.62 0.77 1.68 22.37 0:08:48 15.83 3.03 27.47 0.69 1.55 20.71 0:09:19 15.68 3.09 30.15 1.08 1.76 23.44 0:09:51 15.81 3.03 25.03 0.54 1.42 18.97 0:10:20 15.46 3.15 29.48 0.87 1.8 23.93 0:10:51 15.72 3.08 29.11 0.66 1.68 22.44 0:11 :22 15.63 3.12 31.98 0.94 1.88 25.12 0:11 :52 15.7 3.1 32.41 1.2 1.88 25.07 0:12:24 15.69 3.11 29.77 1.06 1.73 23.06 0:12:55 15.41 3.23 33.89 1.09 2.08 27.75 0:13:25 15.71 3.13 36.69 1.18 2.12 28.29 0:13:56 15.9 3.11 36.03 1.16 2 26.61 0:14:27 15.66 3.21 41.01 1.37 2.39 31.86 0:14:57 15.93 3.15 40.83 1.57 2.24 29.93 0:15:29 15.97 3.12 43.49 1.5 2.37 31.59 0:16:00 15.99 3.17 43.17 1.6 2.34 31.18 0:16:30 16.04 3.13 42.39 1.51 2.28 30.34 0:00:35 19.66 0.82 11.54 0.5 0.16 2.15 0:01 :07 16.81 2.49 14.52 0.39 0.66 8.84 0:01 :37 16.59 2.69 15.02 0.39 0.72 9.58 0:02:09 16.5 2 .67 17.06 0.5 0.84 11 .15 0:02:40 16.52 2.8 14.05 0.37 0.68 9.06 0:03:09 17.11 2.66 13.69 0.47 0.57 7.55 0:03:40 17.14 2.69 10.99 0.28 0.45 5.99 0:04:11 17.16 2.63 13.3 0.28 0.54 7.24 0:04:42 16.9 2.66 21.21 0.34 0.93 12.44 0:05:13 16.72 2.71 22.21 0.77 1.03 13.68 0:05:44 16 2.82 26.24 0.62 1.44 19.22 0:06:14 14.89 2.97 32.87 0.63 2.25 30.06 0:06:44 14.8 3.01 42.66 0.85 2.97 39.61 375 Table 36 Subject 22 1 levels detennination test (cont.). Time 02 h:m:s CO2 VE Vr Vo2 Vo2 % 0:07:15 % (Umin) (L) (Umin) (mUkg/min) 0:07:46 15.06 3.15 47.55 1.76 3.14 41.84 0:08:18 15.72 3.19 52.17 1.41 3 39.99 0:08:48 16.03 3.15 56.15 1.75 3.02 40.23 0:09:18 16.29 3.1 58 1.81 2.93 39.06 0:09:48 16.31 3.09 58.62 1.78 2.95 39.39 0:10:20 16.49 3.02 60.82 1.9 2.94 39.16 0:10:51 16.39 3.03 61.91 1.88 3.06 40.84 0:11 :22 16.46 3.03 62 1.77 3.02 40.21 0:11 :52 16.58 2.98 67.58 1.78 3.19 42.6 0:12:23 16.65 2.94 68.34 1.75 3.17 42.33 16.72 2.88 68.95 1.86 3.15 42.02 0:00:36 19.93 0:01 :07 0.69 13.38 0.36 0.15 1.94 0:01 :38 17.37 2.1 11.9 0.36 0.47 6.28 o:02:08 16.89 2.4 11.15 0.46 0.5 6.66 0:02:39 16.73 2.45 19.12 0.33 0.89 11.9 0:03:09 16.95 2.44 22.2 0.47 0.98 13 0:03:40 15.62 2.66 30.25 0.76 1.82 24.3 0:04:11 15.33 2.75 36.01 0.92 2.29 30.56 0:04:43 15.61 2.78 49.56 1.21 2.98 39.68 o:05:14 16.06 2.78 53.16 1.66 2.89 38.49 0:05:44 16.18 2.85 63.09 1.66 3.32 44.27 0:06:14 16.5 2.83 68.91 1.86 3.35 44.64 0:06:45 16.67 2.86 68.18 1.75 3.16 42.15 0:07:16 16.63 2.87 74.26 1.86 3.48 46.4 0:07:47 16.95 2.78 84.78 1.84 3.66 48.74 0:08:18 17.12 2.8 88.83 2.02 3.63 48.45 0:oa:48 17.21 2.81 99.49 2.07 3.94 52.59 17.44 2.72 105.5 2.2 3.91 52.1 376 Table 37. Subject 224 levels determination test. Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:35 16.5 2.35 18.28 0.52 0.91 14.05 0:01:06 15.98 2.47 19.38 0.45 1.09 16.73 0:01:37 15.58 2 .5 20.28 0.47 1.24 19.06 0:02:08 15.5 2.62 18.3 0.63 1.13 17.43 0:02:38 15.57 2.63 20.2 0.61 1.23 18.91 0:03:10 15.58 2.59 16.34 0.54 15.31 0:03:40 15.18 2.78 14.28 0.43 0.93 14.37 0:04:11 14.92 2.92 18.13 0.53 1.24 19.06 0:04:42 15.48 2.77 19 0.7 1.17 18.03 0:05:13 15.82 2.73 18.48 0.62 1.06 16.34 0:05:44 15.89 2.72 17.33 0.6 0.98 15.11 0:06:15 15.8 2.7 16.92 0.63 0.98 15.06 0:06:46 16.02 2.67 16.93 0.55 0.93 14.35 0:07:16 15.94 2.72 17.45 0.55 0.98 15.03 0:07:47 15.96 2.73 22.45 0.72 1.25 19.23 0:08:17 16.28 2 .63 22.97 0.82 1.19 18.34 0:08:48 16.31 2 .64 25.76 0.92 1.33 20.44 0:09:19 16.42 24.24 0.78 1.22 18.75 2.6 0:09:50 16.47 23.29 0.8 1.16 17.8 2.57 18.42 0:10:21 16.26 22.91 0.64 1.2 2.6 21.36 0:10:51 16.18 26.11 0.75 1.39 2.61 19.08 0:11 :22 0.72 1.24 16.27 2.59 23.77 22.4 0:11 :53 0.82 1.46 16.27 2.6 27.93 21.03 0:12:24 0.83 1.37 16.45 2.57 27.39 21.54 0:12:54 0.84 1.4 16.27 2.6 26.84 21.32 0:13:25 0.68 1.39 16.26 2.6 26.55 24.79 0:13:56 16.17 2.64 30.21 1.01 1.61 1.47 22.6 0:14:27 16.37 2.6 28.86 0.8 1.5 23.01 0:14:58 16.3 2.6 28.87 0.82 25,27 0:15:28 16.23 2.57 31 .12 0.97 1.64 22.83 0:15:59 16.31 2.58 28.7 0.93 1.48 25.49 0:16:30 16.24 2.57 31.52 0.83 1.66 21.96 0:17:01 16.47 2.51 28.61 0.79 1.43 24.13 0:17:32 16.33 2.57 30.49 0.92 1.57 24.24 0:18:02 16.37 2.55 30.87 0.88 1.58 25.01 0:18:33 16.38 2.54 31.92 0.86 1.63 23.8 0:19:04 16.43 2.53 30.77 0.79 1.55 24,27 0:19:34 16.47 31.7 0.74 1.58 27.45 2.53 0:20:05 16.41 2.55 35.29 0.93 1.78 25,97 0:20:36 16.61 35.08 0.97 1.69 2.49 1.74 28.92 0:00:36 15.61 2.65 28.77 0.82 26,56 0:01:06 27.66 0.79 1.59 30.86 15.82 2.69 0:01;37 31.13 0.71 1.85 30,67 15.65 2.78 1.84 0:02:07 32.53 0.86 32.16 15.89 2.76 1.93 0:02:38 16.07 2.77 35.64 0.99 377 Table 37. Subject 224 levels determination test (cont.). Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (rnUkg/rnin) 0:03:09 16.22 2.8 37.99 0.97 1.98 33.06 0:03:40 16.36 2.76 33.94 0.89 1.71 28.57 0:04:11 16 2.87 39.79 1.17 2.18 36.37 0:04:42 16.32 2.82 40.15 1.09 2.04 34.05 0:05:13 16.39 2.8 41.07 1.03 2.06 34.31 0:05:43 16.38 2.81 42.67 1.02 2.14 35.67 0:06:14 16.49 2.8 42.52 0.92 2.08 34.63 0:06:45 16.52 2.77 47.9 1.06 2.32 38.72 0:07:15 16.66 2.73 49.6 1.1 2.32 38.73 0:07:45 16.69 2.73 50.79 1.13 2.36 39.35 0:08:16 16.76 2.69 54.25 1.15 2.48 41.26 0:08:47 16.79 2.67 51.87 0.98 2.35 39.23 0:09:18 16.31 2.85 58.79 0.95 2.99 49.88 0:09:48 16.72 2.69 57.94 1.16 2.68 44.66 0:10:19 16.91 2.62 64.74 1.29 2.85 47.46 0:10:50 17.1 2.55 61.45 1.2 2.56 42.73 0:11 :21 17.13 2.53 62.67 1.28 2.6 43.3 378 Table 38. Subject 230 levels determination test. Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:36 17.36 2 .22 21 .34 0.58 0.84 13.23 0:01:07 16.89 2.38 23.65 0.56 1.06 16.72 0:01 :38 16.81 2.47 24.11 0.69 1.1 17.36 0:02:09 16.53 2.52 25.91 0.74 1.27 19.98 0:02:39 16.55 2.53 21.07 0.7 1.03 16.19 0:03:11 16.58 2.53 25.03 0.7 1.21 19.1 0:03:41 16.66 2.48 19.53 0.72 0.93 14.61 0:04:12 16.54 2.53 19.99 0.69 0.98 15.41 0:04:43 16.49 2.55 23.43 0.94 1.16 18.27 0:05:13 16.85 2.45 18.32 0.76 0.83 13.05 0:05:44 16.58 2.72 19.39 0.81 0.93 14.63 0:06:15 16.44 2.67 24.96 0.81 1.24 19.57 0:06:46 16.68 2.46 21.9 0.63 1.04 16.33 0:07:16 16.76 2.52 23.99 0.73 1.11 17.43 0:07:47 16.42 2.56 29.06 0.68 1.46 23.05 0:08:18 16.44 2.54 28.74 0.8 1.44 22.67 0:08:48 16.6 29.94 0.88 1.44 22.73 2.53 0:09:20 29.58 0.74 1.45 22.9 16.52 2.51 0:09:51 29.08 0.77 1.4 22.01 16.6 2.56 22.4 0:10:21 0.86 1.42 16.54 2 .56 29.12 22 0:10:52 0.91 1.4 16.62 2 .56 29.22 20.54 0:11 :23 0.72 1.3 16.66 2.53 27.53 19.89 0:11 :53 0.64 1.26 16.57 2.6 26.1 13.67 0:12:24 0.61 0.87 16.8 2.48 18.95 18.26 0:12:55 0.58 1.16 16.17 2.77 21.89 24.48 0:13:25 15.89 2.86 27.63 0.81 1.55 21.25 0:13:56 16.4 2.65 26.79 0.74 1.35 19.63 0:14:27 16.71 2.49 26.65 0.81 1.25 22.66 0:14:58 16.38 2.63 28.41 0.81 1.44 1.56 24.61 0:15:29 16.46 2.63 31.48 1.05 21.98 1.4 0:16:00 16.73 2.56 30.04 0.73 23.4 0:16:29 16.45 2.62 29.84 0.85 1.49 29,33 1.86 0:17:01 16.25 2.72 35.75 0.97 26,57 0:17:31 16.5 2.64 34.33 0.84 1.69 25,22 0:18:02 16.66 33.96 0.92 1.6 24.14 2.62 0:18:33 16.73 33.11 0.87 1.53 25.73 2.61 0:19:04 16.53 33.55 0.99 1.63 26.58 2.66 0:19:34 33.83 0.91 1.69 16.43 2.69 0.82 12.91 0:00:36 17.22 20.13 0.5 17.9 2 .36 1.14 0:01:07 16.74 24.5 0.51 21.27 2 .52 1.35 0:01:38 16.4 2.6 26.78 0.84 26.44 0:02:08 31.13 0.69 1.68 25.07 16.1 2.75 0:02:39 30.48 0.71 1.59 29,97 16.23 2.77 0:03:10 36.42 0.66 1.9 30.17 16.2 2.88 0:03:40 39.08 0.83 1.92 16.45 2.93 379 Table 38. Subject 230 levels determination test (cont.). Time 02 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:04:11 16.61 2.99 40.87 0.87 1.91 30.13 0:04:42 16.79 2.97 41.65 0.82 1.85 29.2 0:05:13 16.73 3.06 46.12 0.96 2.08 32.75 0:05:44 17.01 3.01 47.2 0.87 1.97 31.02 0:06:14 16.83 3.11 53.72 1.17 2.35 36.95 0:06:45 17.23 2.95 54.49 1.11 2.13 33.47 0:07:16 17.31 2.89 58.9 1.25 2.25 35.39 0:07:46 17.41 2.84 56.5 1.2 2.09 32.95 0:08:17 17.36 2.84 63 1.21 2.37 37.39 0:08:49 17.56 2.75 63.64 1.27 2.26 35.53 0:09:19 17.68 2.68 56.56 1.03 1.93 30.39 0:09:50 17.28 2.8 43.93 0.95 1.7 26.85 0:10:21 17.21 2.9 37.41 0.85 1.48 23.28 0:10:51 17.72 2.8 22.22 0.62 0.74 11.64 0:11 :22 18.36 2.43 4.55 0.16 0.12 1.88 380 Table 39. Subject 231 levels determination test. Time 02 CO2 Ve Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkg/min) 0:00:36 17.57 2.05 16.95 0.47 0.63 10.19 0:01:06 17.08 2.19 19.08 0.44 0.82 13.28 0:01 :37 16.7 2.4 15.88 0.38 0.75 12.17 0:02:07 16.61 2.36 18.42 0.54 0.89 14.48 0:02:38 16.36 2.4 17.8 0.52 0.92 14.87 0:03:09 16.36 2.39 17.22 0.32 0.89 14.41 0:03:40 16.23 2.44 19.86 0.62 1.05 17.06 0:04:11 16.32 2.44 19.7 0.64 1.02 16.58 0:04:42 16.37 2 .44 18.57 0.43 0.95 15.44 0:05:12 16.37 2.44 18.36 0.52 0.94 15.26 0:05:43 16.42 2.44 20.3 0.48 1.03 16.68 0:06:14 16.37 2.46 19.72 0.55 1.01 16.4 0:06:45 16.16 2.53 23.34 0.65 1.25 20.32 0:07:15 16.34 2.51 23.47 0.69 1.21 19.61 0:07:46 16.48 2.49 24.23 0.62 1.21 19.56 0:08:17 16.43 2.5 23.67 0.85 1.19 19.33 0:08:47 16.38 2.47 24 0.75 1.23 19.88 0 :09:18 16.23 2.5 23.61 0.64 1.25 20.23 0:09:49 16.36 2.45 24 .63 0.51 1.27 20.5 0:10:20 16.29 2.46 28.19 0.7 1.47 23.88 0:10:51 16.26 32.12 0.71 1.69 27.32 2.51 0:11 :21 16.33 0.7 1.67 27.14 2.5 32.42 0:11 :52 16.25 0.74 1.79 29.09 2.52 34.12 27.7 0:12:24 0.71 1.71 16.24 2.56 32.49 31.01 0:12:54 0.85 1.91 16.03 2.63 34.7 27.81 0:13:25 0.62 1.72 16.37 2.57 33.67 28.83 0:13:56 0.79 1.78 16.37 2.55 34.9 29.92 0:14:26 0.83 1.85 16.3 2.59 35.65 29.54 0:14:57 0.93 1.82 16.5 2.61 37.03 32.73 0:15:28 0.93 2.02 16.56 2.61 41.71 36.33 0:15:59 1.22 2.24 16.33 2.69 43.79 38.16 0:16:29 16.38 2.76 46.75 0.99 2.35 39.72 0:17:00 16.45 2.73 49.44 1.15 2.45 38.21 0:17:31 16.54 2.71 48.64 1.13 2.36 35.65 0:18:01 16.59 2.68 45.91 1.31 2.2 36.58 0:18:33 16.61 2.68 47.43 1.05 2.26 35.28 0:19:03 16.75 2.59 47.2 1.05 2.18 35.27 0:19:34 16.59 2 .56 45.17 1.08 2.18 0.58 9.36 0:00:36 17.54 2 .07 15.41 0.32 11.51 0:01:06 17.02 2.2 16.26 0.54 0.71 13,95 0:01:37 16.77 2.24 18.38 0.29 0.86 13.96 0:02:08 16.76 2.2 18.34 0.35 0.86 12.66 0:02:39 16.59 2.28 15.95 0.64 0.78 11.87 0:03:09 16.69 2.25 15.33 0.61 0.73 10.91 0:03:40 16.77 2.22 14.38 0.4 0.67 381 Table 39. S ubject 23 1 levels determination test (cont.). Time 0 2 CO2 VE Vr Vo2 Vo2 h:m:s % % (Umin) (L) (Umin) (mUkglmin) 0:04:11 16.98 2.15 14.48 0.37 0.64 10.41 0:04:41 16.89 2 .15 15.15 0.34 0.69 11.17 0:05:13 16.93 2.11 10.68 0.21 0.48 7.81 0:05:43 16.94 2.13 3.04 0.16 0.14 2.21 0:06:14 17. 1 2.21 2.92 0.36 0.12 2.02 0:06:46 17.15 2.2 2.87 0.19 0.12 1.96 0:07:17 17.24 2.14 2.95 0.37 0.12 1.96 382 Table 40 . · Subject 001 condition A. Time h:m:s 0:00:37 0:01 :07 0:01:37 0:02:08 0:02:39 0:03:09 0:03:41 0:04:11 0:04:42 0:05:13 0:05:43 0:06:14 0:06:45 0:07:15 0:07:47 0:08:18 0:08:48 0:09:19 0:09:49 0:10:20 o:10:51 0:11:21 0:11 :52 0:12:24 0:12:54 0:13:26 0:13:55 0:14:26 0:14:57 0:1s:27 o:15:58 0:16:30 0:17:oo 0:17:31 o:18:01 0:18:32 0:19:03 0:19:34 0:20:05 0:20:36 0:21:07 o:21:38 o:22:08 o:22:38 0:23:09 0:23:40 16.94 16.44 15.69 15.44 15.3 15.47 15.55 15.63 15.71 16.07 16.1 16.15 16.14 16.33 16.25 15.96 16.01 16.07 15.99 15.95 15.84 15.72 15.67 15.8 15.94 15.94 16.4 16.47 16.1 15.84 16.11 16.39 16.42 16.32 16.16 16.02 16.1 16.23 15.89 16.31 16.26 16.02 15.99 16.02 15.97 16.1 CO2 Ve Vr % (Umin) (L) 2.17 21.47 0.86 2.36 21.8 0.84 2.49 21.48 0.77 2.52 22.02 0.92 2.57 22.47 0.77 2.61 23.43 0.94 2.58 23.17 1.01 2.6 22.35 0.93 2.58 23.66 1.03 2.52 24.44 1.11 2.51 2.51 25.72 1.22 23.99 0.83 2.5 26.53 1.06 2.47 28.46 1.29 2.53 28.8 0.93 2.56 30.81 1.23 2.5 31.75 1.18 2.5 30.94 1.29 2.51 31.59 1.26 2.53 29.9 1.3 2.56 28.26 1.23 2.61 27.67 1.06 2.62 28.64 1.15 2.6 30.58 1.27 2.56 30.62 1.46 2.59 36.11 1.2 2.49 37.59 1.34 2.49 39.53 1.36 2.53 36.54 1.35 2.59 41.06 1.47 2.57 43.24 1.44 2.48 44.53 1.44 2.45 43.56 1.36 2.46 40.31 1.3 2.51 41.34 1.15 2.55 40.6 1.4 2.55 42.12 1.32 2.55 38.27 2.61 43.41 2.52 50.71 2.55 52.13 2.58 58.93 2.6 57.68 2.63 61.36 2.66 60.06 2.62 56.64 1.2 1.4 1.58 1.58 1.73 1.7 1.7 1.4 1.72 Vo2 Vo2 (Umin) (mUkg/min) 0.96 10.46 1.1 12.01 1.28 1.38 1.45 1.46 1.42 1.35 1.4 1.34 1.4 1.29 1.44 1.47 1.51 1.73 1.77 1.7 1.77 1.68 1.63 1.64 1.71 1.78 1.73 2.03 1.91 1.97 1.99 2.36 2.34 2.27 2.2 2.09 2.22 2.25 2.29 2.02 2.47 2.63 2.73 3.26 3.21 3.39 3.35 3.07 383 13.96 15.04 15.75 15.84 15.45 14.64 15.25 14.56 15.24 14.05 15.6 16.01 16.46 18.83 19.23 18.47 19.2 18.31 17.73 17.78 18.58 19.32 18.76 22.12 20.74 21.45 21.62 25.68 25.49 24,68 23.96 22.1 24.16 24.46 24.88 21.93 26,82 28.56 29.66 35.44 34,9 36.86 36,37 33,36 HR (bpm) 66 69 65 68 68 70 76 78 83 83 82 82 95 101 100 98 101 98 123 126 124 APE 6 6 6 7 7 7 8 8 8 11 Table 40. Subject 001 condition A (cont.). Time 02 CO2 VE Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:24:11 15.86 2.73 61.46 1.66 3.5 38.07 126 11 0:24:42 16.1 2.63 60.68 1.56 3.29 35.79 0:25:13 16.03 2.65 58.5 1.67 3.22 35 131 0:25 :44 16.01 2.68 61 .12 1.75 3.37 36.67 0:26:14 16.11 2.63 65.23 1.67 3.53 38.36 0:26:45 16.28 2.59 68.79 1.56 3.58 38.92 0:27:15 16.57 2.51 75.61 1.89 3.67 39.89 0:27:46 16.56 2.54 76.63 1.7 3.73 40.53 152 0:28:17 16.66 2.51 89.94 1.76 4.26 46.32 0:28:49 16.72 2.54 89.25 1.82 4.16 45.2 156 13 0:29:20 16.62 2.56 92.9 1.9 4.44 48.27 0:29:51 16.66 2.54 87.63 1.95 4.15 45.16 157 0:30:20 16.48 2.62 94.58 1.85 4.68 50.86 0:30:51 16.69 2.54 93.04 1.94 4.37 47.51 160 15 0:31:22 16.64 2.57 92.3 2.01 4.38 47.66 0:31 :53 16.45 2.67 89.08 1.71 4.42 48.05 158 0:32:23 16.47 2.67 91.98 2 4.54 49.4 0:32:55 16.44 87.9 1.95 4.37 47.5 158 14 2.68 0:33:26 16.35 2.7 89.73 1.76 4.57 49.62 384 Table 41 S . · ubJect 002 condition A. Time h:m:s 0:00:36 0:01:07 0:01:37 0:02:08 0:02:38 0:03:09 0:03:40 0:04:11 0:04:42 0:05:12 0:05:43 0:06:14 0:06:44 0:07:15 0:07:46 0:08:17 0:08:48 0:09:18 0:09:50 0:10:20 o:10:51 0:11 :23 0:11 :53 0:12:23 0:12:54 0:13:24 0:13:56 0:14:26 0:14:57 o:15:21 0:15:58 0:16:29 o:11:00 0:17:31 o:18:01 0:18:32 0:19:03 0:19:34 o:20:05 0:20:36 0:21:07 0:21:37 02 % 16.96 16.47 16.29 16.04 15.96 16.02 16.06 15.94 15.95 15.85 15.8 15.89 15.95 16.16 16.06 15.78 15.67 15.74 15.61 15.6 15.73 15.93 15.52 15.56 15.75 15.84 15.82 15.75 15.94 16 15.81 15.73 15.56 15.95 16.47 16.61 16.48 16.18 16.43 16.57 16.4 16.53 CO2 VE % (Umin) 2.15 15.32 2.37 15.16 Vr (L) 0.33 0.34 2.46 15.79 0.35 2.51 17.12 0.36 2.49 16.33 0.39 2.51 17.39 0.58 2.5 15.99 0.4 2.52 17.18 0.48 2.5 15.12 0.49 2.55 16.07 0.55 2.56 17.03 0.59 2.56 17.15 0.64 2.54 21.38 0.74 2.49 19.5 0.63 2.53 19.22 0.58 2.59 21.06 0.66 2.62 20.24 0.78 2.62 19.63 0.56 2.68 20.31 0.73 2.66 21.57 0.67 2.67 23.34 0.69 2.68 24.29 o. 71 2.8 27.12 0.9 2. 79 27.42 0.86 2.8 28.32 0.94 2.82 29.36 0.95 2.8 28.8 0.82 2.8 29.12 1.08 2.82 30.4 0.95 2.8 29.92 0.97 2.89 29.74 0.93 2.95 25.68 0.58 3.07 30.64 0.9 2.96 36.59 0.94 2.8 37.73 0.92 2.74 37.43 0.87 2.74 34.11 0.76 2.79 36.62 1.02 2.72 38.17 0.95 2.67 36.43 0.96 2.76 38.12 0.98 2.7 27.24 0.63 Vo2 Vo2 HR (Umin) (mUkg/min) (bpm) 0.68 11.79 0.76 0.83 0.95 0.92 0.97 0.88 0.97 0.85 0.93 0.99 0.98 1.2 1.05 1.06 1.23 1.21 1.15 1.22 1.31 1.37 1.37 1.66 1.66 1.65 1.67 1.65 1.69 1.69 1.65 1.7 1.49 1.83 2.02 1.85 1.78 1.68 1.93 1 .9 1.75 1.91 1.32 385 13.12 14.23 16.33 15.87 16.65 15.2 16.73 14.74 15.96 17.09 16.88 20.76 18.08 18.22 21.19 20.85 19.91 21.1 22.51 23.67 23.56 28.58 28.68 28.43 28.85 28.46 29.2 29.21 28.36 29.32 25.68 31.63 34.87 31.95 30.66 28,88 33.3 32.75 30.26 32.94 22.0 89 97 86 92 88 104 105 108 106 102 105 111 122 133 133 135 142 143 148 146 150 150 148 149 148 153 149 ,so RPE 9 9 9 9 11 11 15 15 15 15 Table 42 S . · ubJect 023 condition A. Time h:m:s 0:00:36 0:01:06 0:01:37 0:02:08 0:02:40 0:03:10 0:03:41 0:04:11 0:04:42 0:05:13 0:05:43 0:06:14 0:06:45 0:07:17 0:07:47 0:08:18 0:08:48 0:09:20 o:09:50 0:10:20 0:10:52 0:11 :22 0:11 :53 0:12:25 o:12:55 0:13:25 0:13:57 0:14:27 0:14:58 o:15:29 o:15:59 0:16:31 0:11:02 0:17:32 o:18:02 0:18:33 0:19:04 0:19:35 0:20:05 0:20:35 o:21 :oa 0:21 :39 0:22:09 0:22:39 0:23:10 0:23:41 17.58 17.52 17.49 17.2 17.05 17.12 17.07 16.97 16.85 17.02 17 17.18 16.88 16.95 17.23 17.36 17.28 16.97 16.88 16.96 17.07 17.05 16.93 17.03 17.17 17.18 17.08 17.17 17.23 17.39 17.36 16.91 16.93 16.99 17.1 17.07 17.28 17.32 17.33 17.12 16.93 16.58 16.69 16.63 16.94 17.29 1.95 2.01 2.02 2.13 2.14 VE Vr (Umin) (L) 11.68 0.23 12.23 0.3 10.97 0.37 11 .57 0.24 12.59 0.29 2.08 11.04 0.28 2.12 11.21 0.29 2.19 2.22 2.15 2.19 2.16 10.52 0.26 11.62 0.26 11.55 0.58 11.65 0.61 10.31 0.19 2.33 10.79 0.27 2.25 12.32 0.23 2.07 11 .62 0.22 2.05 2.09 2.28 2.29 2.26 2.23 2.27 2.26 2.25 2.21 2.25 2.28 2.24 2.22 13.38 0.3 11.3 0.31 14.6 0.36 13.77 0.37 13.4 0.3 13.47 0.35 13.78 0.31 14 0.38 15.46 0.53 13.7 0.38 15.05 0.47 14.36 0.33 13.9 0.25 17.35 0.56 2.2 16.34 0.4 2.23 17.29 0.3 2.39 20.27 0.81 2.35 18.65 0.49 2.36 20.94 0.7 2.3 2.31 19.68 0.76 22.51 0.61 2.21 21.71 0.66 2.24 21.69 0.75 2.21 2.3 2.36 2.45 2.43 2.46 18.85 0.82 16.54 0.49 17.71 0.48 17.46 0.55 18.66 0.55 19.5 0.63 2.39 20.08 0.67 2.25 15.9 0.51 Vo2 Vo2 HR (Umin) (mUkg/min) (bpm) 0.44 9.26 97 0.46 0.42 0.48 0.55 0.47 0.48 0.47 0.53 0.51 0.51 0.43 0.49 0.55 0.48 0.53 0.46 0.64 0.62 0.59 0.58 0.59 0.63 0.67 0.57 0.63 0.61 0.58 0.71 0.64 0.68 0.9 0.83 0.91 0.84 0.96 0.88 0.86 0.75 0.7 0.79 0.85 0.88 0.94 0.89 0.64 386 9.86 8.92 10.24 11.65 10.04 10.31 9.93 11.33 10.78 10.9 9.16 10.38 11.64 10.25 11.32 9.79 13.7 13.27 12.64 12.32 12.65 13.31 14.31 12.19 13.31 13.04 12.33 15.14 13.58 14.47 19.23 17.63 19.43 17.78 20.46 18.69 18.36 15.93 14,83 16.73 18.05 18.77 19.91 18,87 13.57 96 99 94 98 98 96 199 95 199 98 106 95 96 100 106 100 103 101 103 102 101 101 100 120 123 121 124 123 122 125 122 124 122 124 122 123 122 RPE 8 8 8 10 10 11 12 12 12 Table 42. Subject 023 condition A (cont.). Time 02 CO2 VE Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:00:36 17.54 1.93 10.64 0.13 0.4 8.57 0:01:06 17.59 2.01 8.28 0.09 0.31 6.51 0:01 :38 17.71 1.96 6.83 0.08 0.24 5.18 0:02:09 17.52 1.93 11.57 0.16 0.44 9.38 0:02:39 17.48 1.95 15.99 0.33 0.62 13.13 0:03:09 17.77 1.95 15.99 0.28 0.56 11.85 0:03:41 17.52 2.12 20.42 0.49 0.77 16.31 0:04:11 17.01 2.19 21.69 0.77 0.95 20.23 144 0:04:42 16.83 2.22 23.31 0.8 1.07 22.84 143 0:05:13 16.87 2.28 26.72 0.67 1.21 25.81 145 0:05:43 16.84 2.38 27.24 0.85 1.24 26.4 148 14 0:06:15 17.13 2.44 29.69 1.02 1.24 26.34 147 0:06:46 17.24 2.33 28.23 1.13 1.14 24.35 147 0:07:16 17.16 2.36 28.17 1.66 1.17 24.88 147 0:07:46 17.23 1.01 1.1 23.35 150 15 2.43 27.18 0:08:18 17.07 2.51 32.14 1 1.36 28.95 151 0:08:48 17.28 29.8 1.3 1.18 25.21 150 2.44 0:09:19 1.18 25.16 142 15 17.27 2.44 29.59 1.18 0:09:50 17.25 2.42 30.16 1.01 1.21 25.76 0:10:20 17.38 2.26 26.13 1.05 1.02 21.69 0:10:52 17.44 2.23 21.84 0.91 0.84 17.82 0:11 :23 17,75 2.13 16.66 0.48 0.58 12.27 0:11 :53 17.95 12.26 0.26 0.39 8.4 2.08 0:12:24 17.69 0.16 0.41 8.79 2.1 11.62 0:12:54 17.78 0.09 0.33 7.07 2.1 9.68 0:13:25 17.84 0.11 0.31 6.5 2.14 9.14 0:13:57 17.76 15.47 0.4 0.54 11.41 2.09 0:14:27 17.94 0.47 0.65 13.74 2 19.83 0:14:58 18.1 0.49 0.59 12.49 1.97 19.11 0:15:29 0.55 0.84 17.83 17.48 2.19 22.1 155 0:16:oo 1.24 26.44 16.97 2.19 28 0.93 159 0:16:30 1.33 28,39 16.93 2.2 29.75 1.35 31.81 162 0:17:01 1.5 16.9 2.3 33.25 1.33 28,92 159 16 0:17:32 1.36 17.27 2.37 33.94 1.41 30.74 161 0:18:02 17.31 2.37 36.47 1.26 1.44 28.67 162 0:18:33 17.38 2.35 34.8 1.39 1.35 30.25 163 0:19:04 17.33 2.38 36.12 1.29 1.42 31.46 163 18 0:19:35 17.23 2.41 36.5 1.4 1.48 34.19 163 0:20:06 17.31 2.38 40.57 1.35 1.61 29,89 162 0:20:36 1.4 17.48 2.32 37.43 1.21 32.46 164 0:21 :07 17 .35 2.38 39.04 1.63 1.53 34,06 164 18 0:21:38 17.4 2.37 41.67 1.34 1.6 23,87 0:22:08 17.53 2.32 30.42 0.63 1.12 387 Table 43. Subject 145 condition A. Time 02 CO2 VE Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:00:35 18.03 2.28 20.24 0.61 0.62 6.75 0:01:06 17.5 2.54 24.75 0.69 0.91 9.89 97 0:01:37 17.21 2.59 28.4 0.92 1.15 12.45 7 0:02:08 17.3 2.41 26.72 0.76 1.06 11.52 90 0:02:39 17.25 2.39 26.29 0.97 1.06 11.5 0:03:10 17.17 2.41 24.22 0.67 10.87 90 0:03:41 17.1 7 2.39 25.58 0.78 1.06 11.48 0:04:12 17.09 2.38 23.17 0.58 0.98 10.68 95 7 0:04:42 17.06 2.36 24.91 1.07 11.59 0:05:12 16.99 2.37 24.41 0.76 1.07 11.59 92 0:05:43 17.07 2.36 25.04 0.86 1.07 11.6 0:06:14 17.16 2.34 23.03 0.72 0.96 10.39 90 0:06:45 17.02 2.4 28.87 0.9 1.25 13.53 98 7 0:07:16 17.28 2.37 22.82 0.56 0.91 9.9 0:07:47 16.92 2.48 26.38 0.75 1.17 12.67 0:08:18 16.8 2.48 25.16 0.68 1.15 12.5 99 0:08:48 16.62 2.5 28.65 1.06 1.37 14.94 7 0:09:20 16.84 2.47 29.74 0.9 1.35 14.63 100 0:09:50 17.01 2.45 28.34 0.91 1.22 13.31 0:10:20 16.97 2.46 28.08 1.04 1.23 13.34 100 0:10:51 17 2.46 27.69 1.07 1.2 13.01 0:11 :22 16.76 2.49 27.14 0.97 1.26 13.65 96 7 0:11 :53 16.89 2.51 29.7 0.99 1.32 14.38 0:12:24 16.99 2.43 29.35 0.89 1.28 13.87 95 0:12:55 17.13 2.39 24.05 0.83 1.01 10.93 0:13:26 16.62 2.47 27.6 0.75 1.33 14.43 103 7 0:13:56 16.69 2.47 34.13 1.07 1.61 17.51 0:14:28 17.37 2.33 35.02 1.09 1.36 14.8 109 0:14:58 17.16 2.38 34.08 1.03 1.41 15.34 0:15:28 16.48 2.52 36.36 0.91 1.81 19.65 105 0:15:59 16.5 2.53 36.44 1.21 1.8 19.59 0:16:30 16.54 2.53 36.42 1.1 1.78 19.33 109 8 0:17:01 16.57 2.53 38.84 1.21 1.88 20.47 0:17:32 16.7 2.52 36.11 1.16 1.7 18.43 105 0:18:03 16.6 2.56 37.07 0.86 1.78 19.38 0:18:34 16.75 2.49 40.98 1.11 1.9 20.64 99 0:19:05 16.95 2.4 37.12 1.24 1.64 17.79 0:19:35 16.63 2.43 35.98 1.2 1.73 18.78 109 0:20:06 16.49 2.47 40.76 1.31 2.03 22.02 0:20:37 16.71 2.44 37.57 1.02 1.77 19.2 107 8 0:21:07 16.58 2.47 38.2 1.12 1.86 20.17 0:21 :38 16.72 2.46 41.36 1.38 1.93 21.03 0:22:09 16.68 2.46 45.56 1.42 2.16 23.43 121 0:22:40 16.43 2.54 49.34 1.5 2.48 26.93 0:23:11 16.61 2.51 53.78 1.54 2.59 28.11 131 0:23:42 16.77 2.5 56.52 1.66 2.6 28.3 9 388 Table 43. Subject 145 condition A (cont.). Time 02 CO2 VE Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:24:13 16.94 2.45 60.7 1.6 2.68 29.11 133 0:24:43 16.86 2.42 59.44 1.52 2.69 29.2 0:25:14 16.86 2.44 60.22 1.67 2.72 29.53 132 0:25:44 17.01 2.39 57.85 1.38 2.51 27.23 9 0:26:15 16.6 2.47 61.47 1.71 2.97 32.27 137 0:26:46 16.86 2.41 61.38 1.66 2.77 30.15 0:27:17 17.08 2.32 61.62 1.62 2.63 28.59 135 0:27:48 16.94 2.32 59.34 1.52 2.63 28.61 138 9 0:28:19 16.9 2.35 67.45 1.53 3.02 32.83 0:28:50 17.08 2.37 65.01 1.63 2.76 30.03 0:29:20 17.02 2.39 72.36 1.72 3.12 33.94 147 0:29:50 17.09 2.37 79.21 1.84 3.36 36.52 0:30:22 17.16 2.33 82.42 2.01 3.43 37.29 158 0:30:52 17.3 91.36 1.99 3.64 39.58 11 2.31 0:31 :23 17.41 2.27 89.71 1.99 3.46 37.61 159 0:31:54 17.38 2.32 88.21 2.1 3.42 37.22 0:32:25 17.32 2.32 90.67 1.93 3.59 39.03 160 0:32:56 3.65 39.67 11 17.43 2.27 95.07 2.02 0:33:26 17.52 1.98 3.55 38.59 163 2.22 95.04 0:33:58 17.53 2.18 97.5 2.12 3.64 39.6 0:34:28 17.65 2.14 3.69 40.13 162 2.13 102.7 0:34:59 3.87 42.1 164 11 17.53 2.13 103.4 2.03 0:35:30 17.53 93.41 1.87 3.5 38.01 2.13 389 Table 44 S . · ubJect 173 condition A. Time h:m:s 0:00:37 0:01:08 0:01:38 0:02:09 0:02:40 0:03:11 0:03:42 0:04:13 0:04:43 0:05:13 0:05:45 0:06:16 0:06:47 0:07:18 0:07:48 0:00:1 9 0:08:49 0:09:20 0:09:51 0:10:22 0:10:53 0:11 :24 0:11 :55 0:12:26 0:12:57 0:13:27 0:13:57 0:14:28 0:14:59 0:15:30 0:16:01 0:16:32 0:17:02 0:17:33 o:18:04 o:10:35 0:19:06 0:19:37 0:20:07 0:20:38 0:21:09 0:21:40 0:22:11 0:22:41 0:23:12 0:23:43 17.92 17.49 17.1 16.87 16.82 16.89 16.81 16.87 16.85 16.87 16.97 16.72 16.81 16.98 17.06 16.99 16.8 16.62 16.55 16.56 16.69 16.7 16.72 16.69 16.58 16.37 16.79 16.72 16.66 16.54 16.68 16.57 16.56 16.44 16.45 16.57 16.5 16.32 16.6 16.52 16.64 16.9 16.87 17.27 17.41 17.54 CO2 VE Vr Vo2 Vo2 HR min) (L) (Umin) (mUkg/min) (bpm) % (U 2.34 18.09 0.57 0.58 8.9 11.35 2.45 19.86 0.83 2.53 19.52 0.59 2.61 19.48 0.63 2.61 19.46 0.67 2.59 21 .18 0.64 2.58 18.97 0.63 2.59 19.98 0.71 2.61 19.16 0.83 2.63 21.4 0.86 2.63 17.85 0.62 2.76 17.48 0.76 2.73 20.86 0.67 2.61 25.65 0.88 2.61 27.28 1.01 2.65 25.48 1.34 2.76 23.72 1.19 2.85 22.13 0.96 2.86 25 .05 0.89 2.83 25.95 1.37 2.82 24.76 1.18 2.83 2.8 2.84 2.86 25.72 0.95 23.77 1.03 23.59 1.31 23.4 0.78 2.94 27.81 1.32 2.83 26.04 1.18 2. 73 27 .27 1.24 2.78 28.26 1.41 2.84 29.82 1.66 2.81 30.45 1.69 2.86 29.52 1.34 2.86 27.82 1.46 2.87 28.53 1.43 2.86 30.83 1.71 2.82 28.94 1.03 2.84 29.09 1.21 2.91 30.87 1.62 2.85 30.17 1.16 2.85 31.22 1.16 2.78 27.33 1.24 2.74 21.85 0.91 2.77 17.75 0.55 2.56 14.97 0.58 2.49 13.3 0.38 2.45 17.18 0.51 0.74 0.82 0.87 0.88 0.94 0.86 0.89 0.86 0.95 0.77 0.8 0.94 1.11 1.15 1.09 1.07 1.04 1.2 1.24 1.15 1.18 1.09 1.09 1.11 1.39 1.17 1.26 1.32 1.43 1.41 1.41 1.33 1.41 1.52 1.38 1.42 1.56 1.43 1.51 1.28 0.96 0.78 0.59 0.51 0.63 390 12.56 13.34 13.52 14.42 13.21 13.71 13.21 14.64 11.86 12.38 14.44 17.04 17.69 16.8 16.41 16.04 18.44 19.12 17.63 18.22 16.8 16.78 17.09 21.36 18.03 19.33 20.34 22.05 21.72 21.65 20.48 21.65 23.32 21.24 21.77 24.06 21.95 23,19 19.76 14.72 12.04 9.11 7.77 9.65 89 90 84 88 90 91 99 98 104 103 98 104 103 109 111 109 117 115 113 113 117 RPE 7 8 8 12 12 12 13 13 13 Table 44 . Subject 173 condition A (cont.). Time 02 CO2 VE Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:24: 14 17.64 2 .38 11.58 0.28 0.41 6.3 0:24:44 17.59 2 .4 12.2 0.39 0.44 6.76 0;25:15 17.47 2.42 16.37 0.63 0.61 9.43 0:25:46 17.77 2 .37 20.19 0.42 0.68 10.49 0:26:17 17.9 2.41 24.27 0.87 0 .78 11.97 0:26:48 17.05 2.64 27.49 0.72 1.16 17.81 124 0:27:18 16.46 2 .75 37.88 1.31 1.87 28.74 128 391 Table 45 S . · ubJect 2 14 condition A. Time h:m:s 0:00:36 0:01 :07 0:01 :38 0:02:09 0:02:39 0:03:10 0:03:41 0:04:12 0:04:43 0:05:13 0:05:43 0:06:14 0:06:46 0:07:17 0:07:46 0:08:17 0:08:48 0:09:20 0:09:51 0:10:20 o:10:51 0:11 :22 0:11 :54 0:12:25 o:12:55 0:13:25 0:13:56 0:14:27 0:14:58 0:15:29 0:15:59 0:16:30 0:17:01 0:17:32 0:18:03 0:18:33 0:19:04 0:19:35 0:20:07 0:20:37 0:21:07 0:21:38 0:22:09 0:22:40 0:23:11 0:23:42 17.29 16.89 16.49 16.4 16.22 16.6 16.44 16.18 16.28 16.49 16.41 16.41 16.6 16.53 16.52 15.97 16.02 16.11 16.55 16.18 16.34 16.49 16.39 16.44 16.34 16.33 16.43 16.67 16.51 16.51 16.3 16.58 16.55 16.52 16.51 16.34 16.44 16.43 16.41 16.62 16.65 16.91 17.15 17.4 17.29 17.21 CO2 VE % (Umin) 2.55 23.47 2.78 26.96 2.96 27.3 2.95 23.89 2.99 29.05 2.92 25.44 2.94 23.61 3.01 26.35 3.01 26.44 2.93 25.74 2.96 25.23 2.96 27.17 2.91 27.3 2.98 32.06 3.02 29.71 3.12 31.68 3.13 31.77 3.11 37.25 2.98 32.85 Vr (L) 0.94 1 1.14 0.77 1.08 0.85 0.79 1.15 0.98 1.12 1.15 1.18 1.05 1.23 0.93 1.44 1.32 1.62 1.17 3.09 34.26 1.63 3.07 35.17 1.26 3.05 33.91 1.3 3.09 36.7 1.05 3.01 31.48 0.95 3.03 35.39 1.31 3.11 35.03 1.67 3.1 35.6 1.48 3.02 36.49 1.4 3.07 38.2 1.47 3 38.36 1.48 3.1 40.08 1.6 3.04 40.62 1.5 3.02 38.47 1.48 3.02 40.43 1.44 3.03 37.83 1 ,51 3.13 39.73 1.47 3.09 39.31 1.51 3.09 39.14 1.4 3.07 39.71 1.47 3.03 40.59 1.5 3.01 33.06 1.5 2.93 25.06 0.52 2.79 19.29 0.54 2.69 14.27 0.45 2.63 13 0.32 2.58 18.08 0.62 Vo2 Vo2 (Umin) (mUkg/min) 0.92 11.97 1.18 1.32 1.18 1.5 1.2 1 .16 1.38 1.35 1.25 1.25 1.34 1.29 1.53 1.42 1.73 1.71 1.97 1.56 1.78 1.76 1.63 1.81 1.54 1.77 1.75 1.74 1.68 1.83 1.84 2.02 1.91 1.82 1.93 1.82 1.98 1.91 1.91 1.95 1.89 1.53 1.08 0.78 0.54 0.51 0.73 392 15.32 17.13 15.34 19.49 15.56 15.03 17.84 17.48 16.17 16.18 17.41 16.68 19.9 18.44 22.42 22.22 25.5 20.25 23.12 22.83 21 .16 23.51 19.97 22.97 22.73 22.51 21.78 23.69 23.89 26.18 24.77 23.66 25.06 23.54 25.71 24,81 24.78 25.28 24.55 19,82 14.02 10.13 6.96 6.61 9.46 HR (bpm) 100 90 91 94 92 98 107 106 113 113 109 118 112 122 113 119 119 116 126 RPE 6 6 7 7 8 9 9 9 Table 45 S . · ubJect 214 condition A (cont.). Time 02 h:m:s % 0:24:12 0:24:43 0:25:15 0:25:45 0:26:16 0:26:46 0:27:17 0:27:49 0:28:19 0:28:49 0:29:20 0:29:51 0:30:23 0:30:53 0:31 :23 0:31:54 0:32:25 0:32:56 0:33:26 0:33:57 0:34:28 0:35:oo 0:35:31 0:36:01 0:36:31 0:37:02 0:37:33 0:38:05 0:38:34 0:39:05 0:39:36 0:40:07 0:40:38 0:41:08 0:41:39 0:42:09 0:42:41 0:43:12 0:43:42 0:44:13 0:44:44 17.21 17.32 16.84 16.29 16.04 16.2 15.89 15.92 16 16.2 16.34 16.28 16.31 16.33 16.29 16.45 16.24 16.54 16.75 17.69 18.34 18.19 17.96 17.91 17.71 17.49 16.78 16.06 16 16.1 16.39 16.26 16.63 16.66 16.73 16.78 16.86 16.8 16.56 16.87 16.91 CO2 Ve Vr % (Umin) (L) 2.59 20.71 0.61 2.67 27.93 0.93 2.95 36.09 1.44 3.08 38.08 1.52 3.13 46.68 1.67 3.11 45.42 1.82 3.32 46.68 2.03 3.38 47.28 2.25 3.42 50.95 2.04 3.36 50.29 2.1 3.27 51.63 2.07 3.26 53.12 2.12 3.26 52.18 2.17 3.25 53.44 2.23 3.24 53.74 2.07 3.17 53.81 2.24 3.28 53.75 2.15 3.15 45.17 1.88 3.12 33.24 0.81 2.86 29.08 1.38 2.52 22.7 0.42 2.45 18.33 0.48 2.46 17 .56 0.53 2.39 15.17 0.33 2.41 24.5 0.61 2.65 33.6 1.29 2.98 41.73 1.3 3.02 49.08 1.89 3.11 60.23 2.23 3.23 63.02 2.42 3.26 68.99 2.65 3.4 70.61 2.72 3.26 77.31 2.97 3.27 75.46 2.79 3.21 77.78 2.88 3.17 76.85 2.74 3.08 80.94 2.89 3.08 74.7 2.58 3.21 78.58 2.81 3.07 83.66 2.61 3.02 73.89 2.05 Vo2 Vo2 HR (Umin) (mUkg/min) (bpm) 0.83 10.83 1.08 1.59 1.93 2.5 2.35 2.57 2.58 2.72 2.57 2.55 2.67 2.61 2.65 2.69 2.6 2.72 2.13 1.48 0.97 0.59 0.52 0.55 0.48 0.84 1.23 1.86 2.63 3.26 3.31 3.37 3.54 3.54 3.43 3.48 3.39 3.52 3.3 3.68 3.62 3.17 393 14 20.56 24.98 32.45 30.45 33.33 33.43 35.28 33.31 33.09 34.65 33.79 34.4 34.95 33.71 35.32 27.67 19.25 12.64 7.7 6.71 7.08 6.29 10.94 15.96 24.19 34.16 42.31 42.98 43.73 45.96 45.98 44.46 45.11 44.02 45.62 42.82 47.79 46.97 41.15 135 139 138 141 144 146 147 158 167 169 172 173 73 169 RPE 12 12 12 15 15 15 Table 46 S . · ubJect 221 condition A. Time h:m:s 0:00:36 0:01 :06 0:01 :38 o:02:08 0:02:39 0:03:09 0:03:40 0:04:11 0:04:42 0:05:13 0:05:43 0:06:14 0:06:45 0:07:16 0:07:46 0:08:17 0:08:48 0:09:19 0:09:50 0:10:21 o:10:52 0:11 :22 0:11 :53 0:12:25 o:12:55 0:13:25 0:13:56 0:14:27 0:14:58 0:15:30 o:16:00 0:16:30 0:17:01 0:17:32 o:18:03 o:18:33 0:19:04 0:19:35 0:20:05 0:20:35 o:21 :08 0:21:39 0:22:09 0:22:40 0:23:11 0:23:41 E r V02 Vo2 HR APE CO2 V V % (Umin) (L) (Umin) (mUkg/min) (bpm) 17.27 16.77 15.95 15.77 15.71 15.81 15.77 15.63 15.76 15.85 15.76 15.53 15.7 15.76 15.47 14.96 14.93 15.17 15.12 15.5 15.47 15.35 15.35 15.57 15.51 15.47 15.48 15.39 15.31 15.32 15.33 15.43 15.44 15.41 15.5 15.54 15.5 15.47 15.42 15.7 15.97 16.4 16.65 16.82 16.96 16.81 2.55 18.82 0.34 0.75 9.95 2.65 21 .36 0. 76 0.98 13.02 102 2.79 22.29 1.01 1.24 16.56 2.84 21.69 1.2 1.25 16.72 99 2.86 21.98 0.69 1.29 17.16 2.85 20.63 0.9 1.18 15.76 105 2.88 22.49 0.7 1.3 17.32 2.9 21.87 0.52 1.3 17.33 15.84 16.09 16.59 2.9 20.56 0.57 2.89 21.28 0.82 2.93 21.56 0.86 2.98 20.21 0.58 3 23.12 0.72 2.98 25.55 0.61 3.08 27.85 0.96 3.24 31.04 1.03 3.31 31.89 1.33 3.27 30.51 1.17 3.29 34.8 1.66 3.2 33.82 1.35 3.21 32.88 1.49 3.29 33.33 1.39 3.29 34.45 1.23 3.25 34.71 1.65 3.28 34.29 1.49 3.25 33.66 1.25 3.23 38.38 1.83 3.28 38.42 1.92 3.39 38.4 1.75 3.36 41 .16 1.71 3.42 41.87 2.09 3.39 40.63 2.03 3.37 40.19 1.91 3.4 41.99 2.1 3.33 42.83 2.04 3.3 41.92 2.1 3.32 43.55 1.81 3.32 41.48 1.73 3.33 45.19 1.96 3.21 37.25 1.77 3.17 36.35 1.45 3.06 33.85 1.54 2.95 31 1.11 2.79 23.15 1.01 2.68 23.6 1.03 2.66 22.94 0.96 1.19 1.21 1.24 1.22 1.35 1.47 1.7 2.08 2.14 1.96 2.26 2.04 2 2.07 2.13 2.06 2.05 2.04 2.32 2.36 2.39 2.56 2.59 2.46 2.43 2.56 2.57 2.49 2.61 2.5 2.76 2.15 1.98 1.67 1.44 1.03 1.02 1.04 394 16.3 17.95 19.63 22.64 27.75 28.56 26.15 30.08 27.16 26.6 27.56 28.46 27.4 27.39 27,17 30.96 31.49 31.88 34.09 34.56 32.86 32.44 34.12 34.26 33.25 34.84 33,37 36.74 28.69 26.36 22.26 19.2 13.79 13.6 13.81 98 101 98 115 123 123 125 127 126 124 141 148 144 145 148 153 151 10 11 11 12 12 12 13 13 13 Table 46. S . ubJect 221 condition A (cont.) . Time h:m.·s 0:24:12 0:24:43 0:25:14 0:25:44 0:26:16 0:26:47 0:27:17 0:27:47 0:28:18 0:28:49 0:29:20 0:29:51 0:30:22 0:30:52 0:31 :23 0:31:54 0:32:25 0:32:56 0:33:27 0:33:57 0:34:28 0:34:59 0:35:30 0:36:0o 0:36:31 0:37:02 0:37:33 0:38:03 0:38:34 0:00:35 0:01:06 0:01:36 o:02:oa 0:02:39 0:03:09 0:03:40 0:04:11 0:04:42 0:05:12 o:05:43 o:os:14 0:06:45 0:07:16 % 16.64 16.22 16.09 16.45 16.76 16.89 17.04 17.15 17.12 17.28 17.26 17. 14 17.45 17.58 16.24 15.22 14.79 14.63 15.59 16.05 16.37 16.37 16.51 16.44 16.45 16.5 16.45 16.61 16.68 15.22 14.91 15.79 16.52 16.83 16.81 16.83 16.88 16.94 17 17.07 17.07 17 16.84 VE Vr Vo2 Vo2 HR APE % (Umin} (L} (Umin} (mUkg/min} (bpm) cen 2·63 23.89 0.65 1.13 15.08 1.1 14.62 12.95 10.4 9.24 9.16 8.87 7.78 8.36 2.7 20.9 0.84 2.7 17.92 0.66 2.62 15.66 0.31 2.54 15.03 0.26 2.5 15.41 0.3 2.49 15.59 0.32 2.5 14.12 0.29 2.53 15.07 0.37 2 .47 12.49 0.36 2.5 12.58 0.31 2.52 18.86 0.48 2.38 20.02 0.26 2.29 21.75 0.46 2.64 26.55 0.78 2.83 30.76 0.85 3.04 37.27 1.49 3.25 52.15 2.17 3 .18 61.64 2.05 3.11 71.09 2.15 3.07 69.83 2.12 3.06 74.87 2.14 2.98 71.54 2.1 2.97 72.83 2.14 2.97 74.93 2.08 2.91 71.47 2.1 2.92 77.86 2.1 2.83 80.06 2.05 2.77 73.73 1.94 2.85 35.6 1.19 3 56.11 1.81 2.85 73.82 2 2.81 86.84 2.17 2 .83 88.65 2.22 2.88 90.74 2.33 2.89 92.37 2.37 2.88 95.56 2.39 2.86 95.06 2.21 2.8 99.92 2.13 2.74 97.44 1.91 2.72 96.13 1.75 2.71 95.44 1.84 2.76 29.39 0.53 0.97 o.78 0.69 0.69 0.67 0.58 0.63 0.49 0.5 0.78 0.76 0.79 1.39 1.99 2.6 3.71 3.65 3.8 3.46 3.72 3.44 3.57 3.67 3.46 3.81 3.78 3.43 2.31 3.83 4.25 4.21 3.94 4.04 4.09 4.17 4.08 4.23 4.05 4.01 4.06 1.31 395 6.6 6.7 10.41 10.1 10.56 18.54 26.58 34.64 49.49 48.72 50.72 46.19 49.58 45.84 47.63 48.89 46.17 50.82 50.36 45,67 30.74 51.08 56,64 56.1 52.48 53,88 54,55 55.62 54.44 56.38 54,06 53.49 54,16 17,46 171 177 182 185 186 185 188 192 18 196 199 20 201 206 20 Table 47 . · Subject 224 condition A. Time h:m.·s 0:00:36 0:01:08 0:01 :38 0:02:09 0:02:40 0:03:10 0:03:42 0:04:12 0:04:42 0:05:14 0:05:44 0:06:15 0:06:46 0:07:16 0:07:48 0:08:18 0:08:49 0:09:20 0:09:51 0:10:22 0:10:52 0:11 :23 0:11 :55 0:12:25 0:12:56 0:13:27 0:13:57 0:14:29 0:14:59 0:15:30 0:16:01 0:16:31 0:17:03 0:17:33 0:18:04 0:18:35 0:19:05 0:19:37 0:20:07 0:20:38 0:21:09 0:21 :39 0:22:11 0:22:41 0:23:12 0:23:43 % 17.24 16.28 15.77 15.39 15.27 15.5 15.85 16.21 16.22 16.31 16.58 16.59 16.64 16.33 16.51 16.52 16.21 15.75 16.34 16.04 16.48 16.33 16.21 16.39 16.54 16.7 16.46 16.24 16.16 16.67 16.39 16.24 16.3 16.15 16.12 16.47 16.66 16.34 16.56 16.5 16.29 16.4 17.09 17.87 17.79 17.81 CO2 VE Vr 0/co ( Umin) (L) 2.32 14.37 0.33 2,66 13.94 0.32 2.83 14.96 0.37 2.9 13.87 0.28 2.98 17.14 0.55 2.95 16.12 0.39 2.88 17.18 0.51 2.82 16.64 0.39 2.88 17.05 0.4 2.87 16.85 0.48 2.77 18.76 0.57 2.77 17.58 0.53 2.78 17.95 0.51 2.85 20.87 0.43 2.82 20.92 0.65 2.83 20.74 0.56 2.87 17.51 0.36 2.95 20.33 0.51 2.9 17.38 0.46 2.99 21.04 0.64 2.9 19.45 0.57 2.96 18.96 0.47 2.99 22.61 0.75 2.97 22.6 0.71 2.91 23.69 0.7 2.85 19.19 0.39 2.94 19.9 0.41 2.97 20.74 0.52 2.96 26.77 0.79 2.84 27.15 0.78 2.96 26.66 0.72 3.04 28.9 0.72 3.04 26.54 0.68 3.12 27.47 0.62 3.11 30.57 0.69 2.98 33.32 0.98 2.92 29.22 0.77 3.03 33.34 0.85 2.92 30.99 0.77 2.93 29.25 0.75 2.98 30.56 0.73 2.92 30.54 0.68 2.67 28.31 0.83 2.41 20.13 0.32 2.4 16.13 0.6 2.36 15.18 0.31 Vo2 Vo2 (Umin) (mUkg/min) 0.58 9.73 0.72 12.05 0.87 0.87 1.09 0.98 0.97 0.87 0.89 0.86 0.9 0.84 0.84 1.06 1.01 1 0.91 1.17 0.88 1.14 0.95 0.95 1.17 1.12 1.14 0.88 0.97 1.07 1.41 1.26 1.32 1.49 1.34 1.44 1.61 1.62 1.35 1.67 1.47 1.41 1.55 1.51 1.18 0.65 o.54 o.5 396 14.43 14.43 18.22 16.37 16.23 14.5 14.79 14.31 14.92 13.95 14.06 17.66 16.9 16.7 15.23 19.58 14.61 18.93 15.8 15.92 19.55 18.72 18.92 14.73 16.18 17.79 23.48 20.99 22.08 24.76 22.4 23.96 26.83 26,99 22.56 27,85 24,56 23,56 25,88 25.24 19.64 10.87 8.98 9.41 HR (bpm) 96 101 91 91 94 99 104 111 104 108 109 107 126 131 128 130 132 131 RPE 6 6 7 8 11 11 13 15 12 Table 47. S . . ubJect 224 condition A (cont.). Time 02 h:m:s % 0:24:14 0:24:46 0:25:15 0:25:47 0:26:18 0:26:48 0:27:20 0:27:50 0:28:21 0:28:51 0:29:21 0:29:53 0:30:24 0:30:55 0:31:25 0:31 :55 0:00:36 0:01 :08 0:01 :38 0:02:09 0:02:40 0:03:10 0:03:42 0:04:11 0:04:43 0:05:13 0:05:44 0:06:15 0:06:46 0:07:17 0:07:47 O:OB:18 0:08:48 0:09:20 0:09:SO 0:10:21 17.8 17.55 17.96 17.96 16.92 16.22 16.15 16.35 16.53 16.75 16.79 16.73 16.74 16.26 16.48 17.07 16.62 16.46 15.97 16.54 16.47 16.31 16.27 16.22 16.37 16.25 16.5 16.43 16.65 16.72 16.78 16.68 16.73 16.73 16.76 16.77 VE Vr % (Umin) (L) 2.35 15.13 0.5 2.48 15.07 0.29 2.4 21.25 0.59 2.41 27.06 0.6 2.6 28.13 0.78 2.69 35.4 0.86 2.89 40.59 1.01 3.16 44.51 1.11 3.29 48.67 1.16 3.3 48.15 1.15 3.3 49.31 1.1 3.35 49.94 1.22 3.3 45.48 0.69 3.48 46.61 0.79 3.4 18.11 0.37 3.09 12.98 0.21 2.36 29.13 0.73 2.41 31.06 0.65 2.51 35.7 1.08 2.53 38.06 1.06 2.67 41.59 1.09 2.78 45.81 1.27 2.96 46.48 1.26 3.08 49.67 1.42 3.06 49.04 1.49 3.13 51.58 1.36 3.03 52.09 1.13 3.04 57.77 1.41 2.97 57.54 1.25 2.93 59.98 1.28 2.89 56.64 1.29 2.88 56.8 1.26 2.85 58.04 1.29 2.82 26.68 0.49 2.8 15.99 0.4 2.79 18.24 0.44 Vo2 Vo2 HR (bpm) (Umin) (mUkg/min) 0.51 8.44 0.55 9.11 0.66 11.07 0.85 1.24 1.86 2.15 2.21 2.29 2.13 2.15 2.22 2.02 2.33 0.86 0.53 1.41 1.56 2 1.86 2.05 2.34 2.38 2.56 2.43 2.63 2.51 2.83 2.66 2.73 2.55 2.62 2.65 1.22 o.73 0.83 397 14.09 20.61 31.02 35.76 36.79 38.16 35.45 35.9 36.93 33.65 38.81 14.31 8.81 23.49 25.99 33.4 31.06 34.23 152 39.02 39,66 167 42.67 40.58 177 43.82 41.8 183 47,16 44.39 186 45.54 42.42 190 43,69 44.22 190 20.31 12.1 13,76 APE 15 19 20 Table 48 . · Subject 230 condition A. Time h:m:s 0:00:36 0:01 :06 0:01:37 0:02:08 0:02:39 0:03:10 0:03:41 0:04:11 0:04:42 0:05:13 0:05:43 0:06:14 0:06:45 0:07:16 0:07:47 0:08:18 0:08:48 0:09:19 0:09:50 0:10:21 o:10:51 0:11 :22 0:11 :53 0:12:24 0:00:36 0:01:06 0:01:38 0:02:09 0:02:39 0:03:10 0:03:41 0:04:11 0:04:42 0:05:14 o:05:44 0:06:14 0:06:45 0:07:16 0:07:47 0:08:18 0:08:48 0:09:19 0:09:5o 0:10:21 0:10:51 % 18.08 17.74 17.02 16.7 16.59 16.67 16.72 16.83 16.94 16.92 16.81 16.73 16.97 16.91 17.01 16.65 16.59 16.61 16.42 16.6 16.66 16.66 16.72 16.7 19.55 18.88 18.17 18.4 18.22 17.73 17.15 16.54 16.4 16.46 16.36 16.6 16.5 16.62 16.67 16.63 16.82 16.92 16.94 16.79 16.69 E r Vo2 Vo2 HR RPE CO2 V V % (Umin) (L} (Umin) (mUkg/min) (bpm} 2·29 16.86 0.4 0.51 7.99 0.6 0.75 0.92 0.98 0.94 0.89 0.96 0.86 0.74 9.42 11.75 14.57 15.48 14.82 82 86 2.49 17.66 0.41 2.64 17.52 0.49 2.62 19.82 0.62 2.59 20.41 0.66 2.59 19.98 0.62 2.62 19.16 0.58 2.61 21.36 0.65 2.58 19.57 0.61 2.65 16.98 0.41 2.72 22.28 0.59 2.74 21.56 0.6 2.67 21.05 0.73 2.72 22.14 0.71 2.72 23.59 0.71 2.81 22.64 0.5 2.77 24.07 0.75 2.71 23.44 0.76 2.79 23.88 0.72 2.79 2.79 2.81 2.83 2.85 1.01 1.34 1.7 1.61 1.69 23.81 24.61 0.74 o.n 24.78 0.73 20.26 0.53 4.36 0.14 8.44 0.19 7.78 0.14 5.94 0.07 7.02 0.09 16.68 0.33 2.14 18.76 o.43 2.4 21.53 0.62 2.55 22.51 o.59 2.6 23.71 0.79 0.11 0.78 2.63 23.51 2.69 23.31 2.68 23.02 0.68 2.72 24.78 0.73 2.7 23.19 0.66 24.34 0.81 2.71 2.75 24.95 0.66 2.71 25.01 0.83 2.67 25.73 0.76 2.66 26.28 0.88 2.75 28.31 0.88 2.79 29.73 0.96 1 0.99 0.91 0.97 1.06 1.15 1.11 1.19 1.13 1.15 1.15 0.93 0.2 0.12 0.17 0.18 0.2 0.5 0.65 0.89 1.1 1.2 1.17 1.18 1.1 1.21 1.1 1.14 1.18 1.12 1.13 1.14 1.28 1.38 398 14 15.13 13.48 11 .72 15.78 15.59 14.28 15.24 15.78 16.67 18.06 17.55 18.68 17.79 18.09 18.19 14.62 3.16 1.97 2.74 2.85 3.07 93 94 107 105 106 104 104 109 107 7.85 98 10.3 14.08 95 17.3 18.85 99 18.41 18.61 101 17,29 19.09 97 17.33 6 6 6 9 8 9 9 17,92 100 18,53 101 9 17,68 17,73 17,99 108 20.11 21.67 112 Table 48. Subject 230 condition A (cont.). Time 02 CO2 VE Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:11 :22 16.62 2.84 30.01 1 1.41 22.23 10 0:11 :53 16.74 2.82 30.1 0.75 1.37 21.6 111 0:12:24 16.64 2.83 31 .38 0.92 1.47 23.14 0:12:54 16.71 2.84 30.83 1.03 1.42 22.3 117 0:13:25 16.82 2.8 30.9 0.94 1.38 21.72 11 0:13:56 16.76 2.79 30.91 1.07 1.4 22.09 188 0:14:26 16.74 2.78 30.03 0.83 1.37 21 .61 0:14:57 16.71 2.85 30.45 0.92 1.4 22.04 115 0:15:28 16.79 2.85 31.16 0.92 1.4 22.05 115 10 0:15:58 16.79 2.81 30.52 0.87 1.37 21 .61 399 Table 49 S . · ubJect 231 condition A. Time h:m:s 0:00:35 0:01 :07 0:01 :38 0:02:09 0:02:39 0:03:10 0:03:40 0:04:11 0:04:42 0:05:13 0:05:43 0:06:14 0:06:45 0:07:16 0:07:46 0:08:18 0:08:48 0:09:18 0:09:49 0:10:20 0:10:51 0:11 :22 0:11 :53 0:12:24 0:12:54 0:13:25 0:13:56 0:14:26 0:14:57 0:15:28 0:15:59 0:16:30 0:17:01 0:17:31 0:18:02 0:18:33 0:19:03 0:19:34 0:20:05 0:20:35 0:00:35 0:01 :07 0:01 :38 o:02:08 0:02:39 17.18 17.33 17.14 17.21 17.24 17.12 17.12 17.07 17.2 17.39 17.3 17.21 17.33 17.34 17.43 17.36 17.36 16.92 16.81 16.71 16.87 16.88 16.97 16.91 16.91 16.93 16.95 16.88 16.84 16.83 16.82 16.9 16.87 16.82 16.78 16.81 16.85 16.94 16.84 16.81 17.03 17.29 17.38 17.43 17.47 CO2 VE Vr Vo2 Vo 2 min) (L) (Umin) (mUkg/min) % (U 1.95 13.08 0.35 0.55 8.97 0.57 0.63 0.58 0.61 0.63 0.61 0.68 0.62 9.29 10.15 9.44 9.89 10.29 1.9 1.99 1.96 1.94 1.98 1.95 1.98 1.95 1.88 1.92 1.91 1.89 1.91 1.84 1.86 1.88 2.02 2.03 2.1 2.07 2.08 2.08 2.09 14.14 14.67 13.87 14.68 14.75 14.21 15.46 14.7 15.16 14.45 15.29 13.56 14.96 15.79 16.93 18.79 19.99 20.33 20.8 20.94 19.38 20.17 20.38 0.46 0.41 0.46 0.41 0.42 0.39 0.5 0.57 0.35 0.45 0.51 0.45 0.31 0.3 0.48 0.48 0.5 0.5 0.59 0.72 0.46 0.59 0.58 2.08 19,5 0.78 2.07 19.76 0.58 2.08 18.95 0.68 2.1 20.02 0.47 2.11 21.23 0.61 2.11 22.12 0.76 2.16 23.56 0.74 2.17 22.19 0.67 2.17 22.66 o. 73 2.16 22.52 0.64 2.18 22.99 0.72 2.2 24.12 0.69 2.18 24.2 0.67 2.16 24.2 0.6 2.16 23.54 o. 78 2.16 23.79 0.72 2.1 15.21 0.66 2.02 12.87 0.3 2.1 12.3 0.34 2.01 11.99 0.43 1.99 13.63 0.34 0.6 0.59 0.64 0.55 0.61 0.62 0.68 0.76 0.91 0.95 1 0.96 0.89 0.9 0.92 0.89 0.89 0.85 0.92 0.98 1.02 1.09 1.01 1.04 1.04 1.07 1.12 1 .11 1.08 1.08 1.11 0.67 0.52 0.48 0.47 0.53 400 9.93 10.94 10.03 9.79 9.57 10.43 8.92 9.82 10.11 11.07 12.24 14.74 15.43 16.14 15.61 14.36 14.58 14.99 14.34 14.47 13.8 14.86 15.88 16.59 17.68 16.3 16.79 16.92 17.42 18.14 18.03 17,58 17,57 17,92 10.81 8.5 7.86 7.58 8.52 HR RPE (bpm) 80 86 6 89 89 6 89 81 7 94 85 7 90 80 7 88 90 85 7 96 98 9 93 94 9 98 95 96 9 Table 49 S . · ubJect 231 condition A (cont.). Time 02 h:m:s CO2 Ve Vr Vo2 % Vo2 HR APE 0:03:09 % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:03:40 17.52 1.98 16.52 0.37 0.63 10.17 0:04:11 17.5 1.98 20.54 0.45 0.79 12.74 0:04:42 16.94 2.11 23.86 0.66 1.07 17.36 0:05:13 16.37 2.23 27.64 0.84 1.43 23.2 16.26 112 0:05:43 2.28 28.94 0.76 1.54 24.89 0:06:15 16.27 2.31 30.52 0.78 1.62 26.19 114 0:06:45 16.3 2.34 30.09 0.86 1.58 25.56 16.31 11 0:07:15 2.37 33.06 0.81 1.73 27.97 121 0:07:47 16.47 2.36 31.8 0.91 1.6 25.89 0:08:17 16.51 2.37 32.42 0.85 1.61 26.14 117 0:08:47 16.61 2.36 31.91 0.69 1.55 25.09 12 0:09:19 16.47 2.42 35.6 1.05 1.78 28.88 123 0:09:49 ' 16.68 2.34 33.42 0.74 1.59 25.82 0:10:20 16.71 2.31 32.63 0.91 1.54 25.03 121 0:10:51 16.74 2.32 34.36 1.07 1.61 26.15 123 12 0:11 :23 16.76 2.3 32.93 0.87 1.54 24.93 16.78 2.25 24.47 0.68 1.14 18.48 0:00:36 19.4 0:01 :07 0.87 3.21 0.1 0.06 0.89 0:01 :38 20.49 0.21 3.81 0.14 0.02 0.31 0:02:08 20.63 0.08 5.06 0.24 0.02 0.3 0:02:39 20.36 0.21 11.31 0.31 0.08 1.23 0:03:10 18.64 1.12 9.14 0.23 0.24 3.86 0:03:40 17.85 1.6 11.63 0.25 0.4 6.56 0:04:12 17.2 1.75 10.65 0.27 0.45 7.36 0:04:42 17.06 1.75 11.28 0.26 0.5 8.12 0:05:13 16.92 1.8 16.13 0.47 0.74 12.05 0:05:44 17.05 1.92 19.34 0.51 0.85 13.81 0:06:15 16.96 1.99 23.63 0.62 1.06 17.23 0:06:45 16.42 2.1 25.85 0.66 1.33 21.59 123 0:07:16 16.04 2.15 30.43 0.71 1.71 27.71 0:07:46 15.77 2.19 34.32 0.95 2.05 33.15 130 0:08:17 15.9 2.29 36.37 1.07 2.1 34 0:08:48 16.1 2.34 39.66 1.1 2.18 35.39 136 15 0:09:20 16.33 2.36 40.22 1.03 2.09 33.92 0:09:50 16.41 2.39 40.83 1.1 2.08 33.7 135 0:10:21 16.48 2.37 40.36 1.06 2.02 32.77 0:10:51 16.48 2.38 41.98 1.13 2.1 34,05 136 15 0:11 :22 16.54 2.35 38.79 0.83 1.92 31,07 0:11 :53 16.54 2.33 40.99 2.03 32,86 134 o: 12:23 16.52 2.31 40.42 1.09 2.01 32.58 16.57 2.26 38.2 0.96 1.88 30.49 141 12 401 Table 50 S . · ubJect 001 condition B. Time h:m:s 0:00:36 0:01 :06 0:01 :37 0:02:08 0:02:38 0:03:09 0:03:40 0:04:11 0:04:42 0:05:12 0:05:43 0:06:15 0:06:45 0:07:16 0:07:47 0:08:17 0:08:47 0:09:18 0:09:49 0:10:20 0:10:51 0:11 :22 0:11 :52 0:12:23 0:12:55 0:13:25 0:13:56 0:14:27 0:14:57 0:15:28 0:15:58 0:16:29 0:17:00 0:17:30 0:18:01 0:18:32 0:19:03 0:19:34 0:20:05 0:20:36 0:21 :07 0:21 :37 o:22:08 0:22:39 0:23:09 0:23:40 02 % 17.21 17.78 17.49 17.33 16.93 16.57 16.38 15.97 16.08 16.18 16.38 16.39 16.46 16.53 16.5 16.42 16.2 16.44 16.25 16.25 16.26 16.24 16.25 16.34 16.35 16.24 16.52 16.44 16.21 16.25 16.07 16.15 16.19 16.15 16.42 16.21 16.08 16.18 16.31 16.04 16.53 16.45 16.18 15.97 16.13 16.01 CO2 % 2.1 2.09 2.15 2.2 2.34 2.4 2.41 2.54 2.55 2.54 2.57 2.58 2.52 2.47 2.57 2.59 2.61 VE (Umin) 28.17 27.71 23.74 23.04 21.61 21.62 19.26 21.36 20.04 20.68 21.43 21.43 25.72 25.57 27.34 25.9 27.32 Vr (L) 1.22 0.87 0.72 0.96 0.57 0.68 0.74 0.69 0.61 0.98 0.79 0.89 0.86 0.8 1.01 0.81 1.01 2.57 26.29 1.1 2.58 26.26 1.05 2.53 26.73 0.95 2.51 27.77 1.26 2.52 27.2 1.09 2.49 27.78 1.03 2.49 27.91 2.52 2.55 2.48 2.53 2.57 2.57 2.63 2.62 2.59 2.59 2.55 2.61 2.64 2.62 2.56 2.66 2.52 2.59 2.64 2.7 26.31 30.55 31.45 31.57 35.92 31.6 35.08 33.83 33.59 35.38 33.53 33.34 35.42 34.68 31.92 41.27 44.49 48.21 47.06 51.44 1.12 1.14 1.17 1.21 1.17 1.28 1.09 1.1 1.21 1.29 1.22 0.93 1.23 1.14 1.24 1.23 1.25 1.39 1.46 1.38 1.43 2.7 50.14 1.39 2.75 49.17 1.4 Vo2 Vo2 (Umin) (mUkg/min) 1.17 12.72 0.95 10.35 0.9 9.77 0.92 9.96 0.96 1.06 0.99 1.2 1.09 1.11 1.09 1.09 1.28 1.26 1.35 1.3 1.45 1.32 1.38 1.41 1.46 1.43 1.46 1.44 1.35 1.61 1.55 1.58 1.9 1.66 1.91 1.82 1.79 1.9 1.69 1.76 1.93 1.85 1.65 2.26 2.18 2.4 2.5 2.86 2,69 2.7 402 10.45 11.5 10.74 13.03 11.9 12.02 11.84 11.81 13.96 13.68 14.64 14.15 15.76 14.32 14.96 15.29 15.84 15.57 15.91 15.64 14.7 17.47 16.84 17.2 20.69 18.03 20.81 19.73 19.43 20.63 18.36 19.17 20.94 20.07 17.94 24,61 23.75 26,1 21.22 31.14 29.24 29,38 HR (bpm) 67 54 67 65 69 65 79 75 72 71 74 78 85 87 86 86 87 112 110 116 RPE 6 6 6 7 7 7 7 7 11 Table 50 s . · ubJect 001 condition B (cont.). Time 02 h:m:s CO2 Ve Vr Vo2 Vo2 HR RPE 0:24:11 % % (Umin) (L) (Umin) (mUkg/min) 16.12 (bpm) 0:24:42 2.74 53.91 1.5 2.89 31.45 0:25:12 16.2 2.71 52.32 1.41 2.76 29.97 124 0:25:43 16.07 2.75 51.32 1.35 2.79 30.27 11 0:26:14 16.06 2.75 52.39 1.22 2.85 30.97 119 0:26:45 16.03 2.76 52.62 1.5 2.88 31.32 0:27:16 16.08 2.76 52.22 1.41 2.82 30.69 122 0:27:47 16.15 2.73 53.83 1.42 2.87 31.22 11 0:28:18 16.27 2.69 54.34 1.36 2.82 30.69 0:28:48 16.25 2.7 61.98 1.55 3.23 35.09 0:29:19 16.37 2.73 65.24 1.52 3.29 35.8 153 0:29:50 16.35 2.76 72.57 1.58 3.68 39.99 0:30:21 16.71 2.74 77.74 1.65 3.59 39.04 156 13 0:30:51 16.77 2.72 78.71 1.67 3.58 38.93 0:31:22 16.71 2.72 78.42 1.51 3.63 39.46 159 0:31:53 16.78 2.65 78.85 1.58 3.6 39.09 0:32:24 16.78 2.65 79.09 1.58 3.61 39.2 160 15 0:32:55 16.78 2.66 82.26 1.52 3.74 40.66 0:33:25 16.88 2.63 81.49 1.51 3.61 39.25 163 0:33:56 16.8 2.66 84.03 1.45 3.8 41.3 0:34:27 16.75 2.65 81.68 1.43 3.75 40.76 162 15 0:34:58 16.68 2.72 46.85 0.76 2.18 23.74 16.63 2.74 8.3 0.18 0.39 4.26 403 Table 51 S . · ubJect 002 condition B. Time 02 h:m:s % 0:00:36 17.71 0:01 :06 17 .48 0:01:37 17.54 0:02:08 17.69 0:02:39 17.86 0:03:10 17.85 0:03:40 17.73 0:04:11 17.68 0:04:42 17.63 0:05:13 17.68 0:05:44 17.52 0:06:15 17.54 0:06:45 17.61 0:07:16 . 17.28 0:07:47 17.32 0:08:19 16.78 0:08:49 16.62 0:09:19 16.47 0:09:50 16.53 0:10:21 16.58 0:10:51 16.58 0:11 :22 16.56 0:11:53 16.55 0:12:24 16.74 0:12:55 16.77 0:13:26 16.47 0:13:57 16.67 0:14:28 16.72 0:14:58 16.31 0:15:29 16.25 0:15:59 16.31 0:16:31 16.47 0:17:01 16.44 0:17:31 16.28 0:18:02 16.59 0:18:33 16.47 0: 19:04 16.46 0:19:35 16.28 0:20:06 16.57 0:20:36 16.58 0:21:07 16.76 0:21 :38 16.85 0:22:09 16.84 0:22:40 16.95 0:23: 11 16.84 0:23:41 16.95 CO2 % 1.88 1.93 1.91 1.87 1.8 1.78 1.84 VE Vr (Umin) (L) 12.54 0.3 11.09 0.38 11.45 0.33 11.65 0.33 12.6 0.27 11.78 0.29 10.6 0.22 1.85 12.38 0.38 1.87 10.59 0.27 1.87 11.26 0.27 1.88 11.27 0.25 1.87 9.47 0.33 1.86 12.61 0.36 2.01 11.74 0.3 2.04 14.64 0.52 2.24 14.48 0.63 2.36 16.09 0.57 2.45 15.55 0.39 2.43 16.69 0.48 2.42 14.67 0.41 2.41 14.81 0.41 2.38 16.34 0.56 2.4 16.7 0.51 2.43 13.52 0.52 2.45 14.28 0.53 2.5 16.13 0.5 2.41 19.16 0.6 2.45 18.21 0.42 2.54 19.44 0.65 2.59 19.13 0.62 2.59 19.94 0.83 2.51 18.85 0.51 2.48 16.96 0.63 2.6 20.35 0.66 2.47 20.15 0.58 2.5 19.9 0.71 2.52 17.75 0.35 2.61 22.2 0.52 2.5 26.14 0.5 2.53 27.63 0.92 2.54 32.63 1.05 2.52 30.8 0.79 2.51 32.72 0.96 2.47 32.03 1.1 2.49 32.76 0.96 2.43 29.16 0.83 Vo2 Vo2 (Umin) (mUkg/min) 0.45 7.74 0.43 0.43 0.42 0.43 0.4 0.38 0.45 0.39 0.41 0.43 0.36 0.47 0.48 0.59 0.68 0.78 0.78 0.82 0.11 0.72 0.8 0.82 0.63 0.66 0.8 0.91 0.85 1.01 1.03 0.94 0.85 1.06 0.98 0.99 0.89 1.16 1.27 1.34 1.5 1.39 1.48 1.41 1.48 1.28 404 7.38 7.49 7.25 7.42 6.97 6.52 7.75 6.74 7.03 7.42 6.2 8.06 8.28 10.18 11.66 13.4 13.42 14.2 12.3 12.44 13.83 14.16 10.89 11.37 13.88 15.72 14.71 17.36 17.29 17.74 16.2 14.71 18.24 16.84 17.11 15.27 19.92 21.9 23.07 25.93 23.88 25.49 24.24 25.54 22.08 HR (bpm) 87 92 96 93 96 90 93 93 95 96 97 93 94 91 104 104 102 111 109 102 107 106 108 131 138 143 143 143 137 134 135 RPE 9 9 9 9 9 9 9 9 13 Table 51 S . · ubJect 002 condition B (cont.). Time 02 CO2 h:m:s VE Vr Vo2 Vo2 HR RPE 0:24:12 % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:24:43 16.6 2.52 31.53 0.83 1.52 26.2 139 0:25:14 16.83 2.48 31.57 0.99 1.43 24.69 142 0:25:45 16.86 2.46 29.65 0.93 1.34 23.03 144 0:26:15 16.69 2.54 31.69 1.09 1.49 25.67 145 0:26:46 16.89 2.5 27.88 0.9 1.24 21.41 150 13 0:27:17 16.63 2.6 31.97 0.89 1.52 26.26 0:27:48 16.95 2.49 32.08 0.92 1.41 24.25 157 0:28:18 16.88 2.55 32.99 0.89 1.47 25.36 155 0:28:49 16.75 2.57 33.09 1.53 26.31 151 15 0:29:20 16.84 2.52 33.78 0.94 1.53 26.33 149 0:29:51 16.85 2.51 33.59 0.99 1.51 26.1 152 0:30:22 16.84 2.5 33.4 1.01 1.51 26.03 152 0:30:52 16.72 2.52 32.53 0.96 1.52 26.17 150 0:31 :24 16.73 2.5 35.93 1.03 1.67 28.83 153 15 0:31 :54 16.86 2.47 34.94 0.92 1.57 27.15 153 0:32:25 16.8 2.48 35.89 1 1.64 28.31 153 0:32:56 16.84 2.47 34.88 1.03 1.58 27.25 152 16.9 2.45 35.39 1.01 1.58 27.22 15 405 Table 52 S . · ubJect 023 condition B. Time h:m:s 0:00:36 0:01 :07 0:01:37 0:02:08 0:02:39 0:03:10 0:03:41 0:04:12 0:04:42 0:05:13 0:05:43 0:06:14 0:06:45 0:07:16 0:07:47 0:08:18 0:08:48 0:09:19 0:09:50 0:10:21 0:10:51 0:11 :23 0:11 :54 0:12:24 0:12:54 0:13:26 0:13:56 0:14:27 0:14:57 0:15:29 0:16:00 0:16:30 0:17:01 0:17:31 0:18:02 0:18:33 0:19:04 0:19:35 0:20:06 0:20:36 0:21:08 0:21:38 0:22:09 02 % 19.55 18.39 18.03 17.99 17.93 17.85 17.58 17.14 17.03 17.13 17.17 17.26 17.35 17.4 17.45 17.31 17.5 17.18 17.12 17.33 17.49 17.59 18.13 17.96 17.92 17.87 17.84 18.02 18.13 17.82 17.32 17.22 17.22 17.16 17.48 17.48 17.53 17.52 17.51 17.57 17.61 17.58 17.54 Ve (Umin} 12.13 9.33 Vr (L) 0.33 0.17 1.01 1.52 1.86 7.64 0.14 1.9 10.11 0.25 1.9 17.26 0.69 1.98 17.71 0.32 2.08 19.92 0.55 2.16 22.8 0.57 2.24 25.61 0.91 2.27 25.48 0.67 2.3 26.79 0.89 2.32 28.76 1.11 2.36 28.15 1.08 2.36 28.17 1.13 2.34 29.16 1.08 2.38 30.67 1.02 2.29 25.53 0.82 2.38 28.75 0.82 2.41 28.65 1.3 2.35 30.22 1.31 2.26 25.93 0.89 2.24 24.03 0.92 2.06 13.26 0.36 2.16 11.24 0.4 2.16 8.98 0.21 2.15 8.55 0.1 2.15 12.4 0.17 1.99 17.65 0.39 2.06 18.98 0.5 2.07 20.2 0.47 2.17 24.62 0.85 2.19 29.24 0.89 2.26 28.49 1.29 2.4 36.25 1.34 2.35 35.83 1.43 2.39 37.99 1.31 2.38 36.3 1.25 1.3 2.35 37.62 2.37 40.05 1.38 2.33 39.2 1.51 2.32 40.19 1.26 2.3 40.28 1.44 2.34 38.79 1.21 Vo2 Vo2 HR (Umin) (mUkg/min) (bpm) 0.18 3.84 93 0.26 5.58 85 0.24 0.33 0.57 0.6 0.73 0.96 1.12 1.07 1.11 1.16 1.1 1.08 1.11 1.21 0.96 1.18 1.2 1.19 0.98 0.87 0.4 0.36 0.29 0.28 0.42 o.56 0.57 0.68 0.98 1.2 1.17 1.5 1.34 1.42 1.34 1.39 1.48 1.43 1.44 1.46 1.42 406 5.18 6.93 12.13 12.72 15.63 20.52 23.73 22.84 23.67 24.67 23.39 23.06 23.53 25.82 20.32 25.2 25.51 25.29 20.76 18.6 8.46 7.64 6.2 6.02 8.85 11.9 12.11 14.57 20.92 25.62 24.86 31.98 28.59 30.26 28.43 29.63 31 .58 30.37 30.73 31 .11 30.28 93 90 92 87 88 85 88 89 92 87 93 88 90 90 85 92 90 92 88 94 93 92 103 112 111 112 111 111 112 112 108 114 116 117 APE 7 8 8 8 8 8 9 10 10 Table 53 S . · ubJect 145 condition B. Time h:m:s 0:00:36 0:01 :06 0:01 :37 0:02:08 0:02:39 0:03:10 0:03:41 0:04:12 0:04:42 0:05:13 0:05:43 0:06:14 0:06:44 0:07:15 0:07:47 0:08:18 0:08:48 0:09:20 0:09:50 0:10:20 0:10:51 0:11 :22 0:11 :52 0:12:23 0:12:55 0:13:26 0:13:56 0:14:27 0:14:58 0:15:28 0:15:59 0:16:29 0:17:00 0:17:31 0:18:02 0:18:33 0:19:05 0:19:35 0:20:06 0:20:36 0:21 :06 0:21 :37 0:22:08 0:22:39 0:23:10 0:23:41 17.85 17.07 16.95 17.28 16.82 16.98 17.21 17.37 17.39 17.4 17.36 17.21 17.16 17.35 17.04 16.97 17 16.92 17.18 17.02 17.31 17.14 17 17.07 17.27 17.33 17.23 16.99 17.07 16.94 16.74 16.97 17 17.06 16.98 17.09 16.85 17.05 16.37 16.94 17.07 17.2 17.16 17.16 17.32 17.27 Ve Vr Vo2 Vo2 (Umin) {L) (Umin) (mUkg/min) 2 24.68 0.62 0.83 9.04 1.03 11.16 2.22 23.85 0.75 2.31 2.21 24.95 0.69 22.56 0.63 2.31 24.68 0.95 2.3 25.96 0.79 2.26 26.45 0.8 2.25 25.4 0.79 2.25 26.43 0.73 2.25 22.67 0.84 2.24 23.17 0.83 2.24 2.25 2.25 2.33 2.38 2.37 2.38 23.34 27.32 24.22 25.49 25.42 27.64 29.68 0.73 1.19 0.76 0.94 0.62 0.77 0.99 2.3 27.08 0.97 2.35 31.05 0.97 2.3 28.58 0.89 2.35 27.13 0.78 2.4 27.45 0.91 2.39 27.4 1.01 2.35 30.21 1.01 2.31 2.33 26.28 1.09 30 1.03 2.38 36.47 1.14 2.33 38.57 1.21 2.38 34.88 1.03 1.07 2.48 2.42 2.39 2.41 2.42 2.41 2.45 2.4 2.56 2.51 2.49 2.45 2.45 2.45 2.38 2.37 37.61 37.86 39.28 38.72 38.82 36.56 39.28 32.43 41.39 41.43 47.52 52.73 54.89 58.76 63.03 60.14 1.26 1.27 1.21 1.29 1.22 1.4 0.98 1.22 1.34 1.44 1.43 1.57 1.59 1.66 1.63 1.11 0.91 1.13 1.14 1.09 1.03 0.88 0.91 0.96 1.14 0.96 1.1 1.11 1.2 1.32 1.12 1.34 1.14 1.14 1.19 1.16 1.21 1.04 1.22 1.59 1.65 1.54 1.75 1.66 1.7 1.65 1.7 1.54 1.77 1.39 2.11 1.82 2.01 2.15 2.26 2.43 2.49 2.41 407 12.02 9.91 12.31 12.42 11.83 10.82 11.16 9.54 9.91 10.44 12.4 10.38 11.95 12.11 13.08 14.34 12.19 14.61 12.36 12.34 12.95 12.66 13.18 11.3 13.28 17.28 17.9 16.76 18.99 18 18.53 17.94 18.43 16.77 19.29 15.09 22.91 19.75 21.87 23.38 24,59 26,37 27,05 26,19 HR (bpm) 76 80 81 73 75 79 79 89 85 86 86 83 99 98 95 97 102 107 106 121 128 133 APE 8 8 8 9 9 9 10 10 10 11 · u ~ect 145 condition B (cont.). Table 53 s b. Time 02 CO2 Ve Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:24:12 17.21 2.4 62.92 1.66 2.56 27.87 136 0:24:42 17.36 2.37 66.7 1.8 2.6 28.28 11 0:25:14 17.45 2.34 65.12 1.63 2.47 26.83 141 0:25:44 17.36 2.37 67.36 1.77 2.62 28.52 0:26:14 17.51 2.31 65.93 1.65 2.46 26.72 143 0:26:45 17.42 2.3 66.12 1.74 2.54 27.58 142 12 0:27:16 17.29 2.33 61.87 1.51 2.47 26.84 0:27:47 17.07 2.41 69.49 1.78 2.96 32.14 0:28:18 17.21 2.38 72.61 1.61 2.97 32.24 156 0:28:48 17.13 2.46 78.15 1.91 3.25 35.33 0:29:20 17.43 2.41 88.92 1.98 3.37 36.65 162 0:29:51 17.71 2.33 94.66 2.2 3.27 35.57 13 0:30:21 17.79 2.29 89.71 2.04 3.03 32.89 162 0:30:52 17.68 2.33 96.64 2.15 3.39 36.82 0:31 :22 17.73 2.31 93.99 2.14 3.23 35.14 161 0:31:53 17.78 2.26 93.84 2.18 3.19 34.67 14 0:32:24 17.62 2.32 90.18 2.05 3.22 35.05 161 0:32:55 17.67 2.26 91.77 1.91 3.24 35.25 0:33:25 17.56 2.28 92.21 2.1 3.38 36.72 162 0:33:56 17.69 2.25 96.29 2.09 3.38 36.75 164 14 0:34:28 17.72 2.23 90.7 1.97 3.15 34.24 0:34:59 17.48 2.33 21.58 0.39 0.81 8.82 408 Table 54 . · SubJect 173 condition B. Time 02 h:m:s % 0:00:36 0:01 :06 0:01 :37 0:02:08 0:02:39 0:03:11 0:03:41 0:04:11 0:04:41 0:05:13 0:05:43 0:06:15 0:06:46 0:07:17 0:07:46 0:08:17 0:08:48 0:09:19 0:09:50 0:10:21 0:10:52 0:11 :22 0:11 :53 0:12:24 0:12:55 0:13:26 0:13:57 0:14:28 0:14:58 0:15:29 0:16:0o 0:16:30 0:17:02 0:17:33 0:18:03 0:18:33 0:19:04 0:19:35 0:00:36 0:01 :06 0:01 :37 0:02:09 0:02:40 0:03:11 0:03:41 18.45 17.58 17.13 16.87 16.79 16.82 16.79 17.11 17.18 17.09 16.91 17 16.95 17.11 17.06 16.97 17.16 17.25 17.04 16.9 17 17.02 17.1 16.99 17.06 17.23 17.06 16.92 16.83 17 17.01 16.93 17.01 16.95 17.01 16.92 16.75 16.85 16.61 16.63 16.61 16.96 17.01 17.07 16.98 r 02 Vo2 HR CO2 Ve V V min) (mUkg/min) (bpm) % (Umin) (L) (U 1,98 21 .91 0.71 0.57 7.64 2.24 21 .11 o.57 o.77 10.26 2.35 23.43 0.76 0.98 13.1 2.43 21.08 0.54 0.95 12.64 2.46 21.74 0.68 2.47 23.29 0.71 2.53 23.95 0.92 2.43 23.38 0.63 2.41 21.91 0.71 2.46 2.54 2.53 2.58 20.89 0.7 22.78 0.91 20.74 0.69 24.56 0.85 2.52 27.56 0.89 2.59 2.7 28.83 1.11 31.97 1.52 2.69 29.85 1.36 2.69 2.71 2.76 2.77 2.71 2.67 29.27 1.05 30.56 1.09 29.26 1.27 29.75 1.19 30.71 1.14 30 1.15 2.71 30.55 1.39 2.73 31.66 1.22 2.64 30.55 1.18 30.6 1.09 2.7 2.72 33.53 1.12 2.73 36.03 1.33 2.72 35.32 1.31 2.73 36.4 1.3 2.78 37.62 1.39 2.73 36.86 1.32 37.68 1.4 34.94 1.29 32.66 1.02 2.75 2.78 2.81 2.85 37.78 1.26 2.8 36.52 1.3 2.85 42.05 1.62 2.9 44.4 1.53 2.99 48.62 1.87 2.9 52.06 1.86 2.9 52.75 1.7 2.87 48.9 1.63 2.89 54.29 1.75 1.06 1.1 0.98 0.9 0.88 1.01 0.89 1.07 1.15 1.22 1.38 1.21 1.16 1.29 1.28 1.26 1.3 1.24 1.31 1.32 1.22 1.28 1.46 1.61 1.5 1.54 1.63 1.56 1.63 1.48 1.41 1.71 1.61 1.98 2.08 2.27 2.22 2.21 2.02 2.3 409 13.3 14.12 14.6 13.1 12.01 11.74 13.41 11.91 14.27 15.34 16.21 18.34 16.17 15.43 17.14 17.06 16.84 17.32 16.58 17.42 17.65 16.27 17.08 19.47 21.5 20.03 20.58 21.73 20.87 21.69 19.74 18.86 22.86 21.53 26.46 27,68 30.33 29.61 29.51 26,94 30.7 98 93 95 91 94 94 116 113 107 108 115 115 110 119 119 116 123 119 126 122 111 142 142 RPE 7 7 7 7 9 9 10 11 11 11 Table 54 Subject 173 condition B (cont.). Time h:m:s 02 CO2 VE Vr % Vo2 Vo2 HR APE 0:04:11 % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:04:42 17.01 2.88 53.84 17.12 1.42 2.27 30.21 143 13 0:05:13 2.82 52.56 17.09 1.46 2.14 28.57 0:05:44 2.83 53.36 1.78 17.02 2.2 29.3 147 0:06:15 16.88 2.85 49.84 1.61 2.09 27.86 0:06:46 2.9 49.77 1.56 2.17 16.79 28.92 146 14 0:07:16 2.9 50.2 1.67 2.24 29.93 0:07:46 16.9 2.88 38.97 1.26 1.69 22.54 0:08:18 16.88 2.91 39.79 1.53 1.74 23.14 0:08:48 17.48 2.73 30.39 0.57 1.11 14.78 0:09:20 17.84 2.6 23.95 0.8 0.77 10.31 0:09:51 18.14 2.45 20 0.61 0.58 7.69 0:10:21 18.14 2.42 14.41 0.53 0.42 5.57 0:10:52 17.92 2.48 16.18 0.45 0.51 6.8 0:11 :22 18.04 2.37 12.29 0.31 0.37 4.97 0:11 :53 17.84 2.4 10.74 0.22 0.35 4.7 0:12:25 17.58 2.49 14.12 0.29 0.51 6.74 0:12:56 17.59 2.49 20.43 0.55 0.73 9.74 0:13:27 17.92 2.41 28.52 1.19 0.91 12.08 0:13:57 17.27 2.69 32.35 1.29 1.27 16.93 0:14:27 16.74 2.8 42.01 1.56 1.92 25.6 0:14:58 16.79 2.76 48.08 1.72 2.17 28.95 0:15:29 16.71 2.85 51.97 2.08 2.38 31.8 153 0:16:00 16.76 2.93 56.42 2.26 2.54 33.9 0:16:31 16.86 2.96 54.28 1.81 2.37 31.62 155 13 0:17:02 16.55 3.11 55.77 2.07 2.64 35.14 0:17:32 16.79 3.07 59.42 2.2 2,63 35.13 157 0:18:02 16.95 3.02 61.95 2.14 2.63 35.03 0:18:34 17 2.98 60.77 2.17 2.54 33.9 161 14 0:19:05 16.88 3.02 62.51 2.32 2.71 36.07 0:19:36 16.9 2.99 59.05 2.11 2.54 33,93 163 0:20:07 16.75 3.06 62.48 2.31 2.81 37.42 0:20:38 16.92 2.99 64.07 2.37 2.75 36.63 164 0:21:07 16.98 2.99 62.22 1.94 2.62 34.96 162 13 0:21:38 16.93 2.99 62.55 2.16 2.68 35.67 17.09 2.91 24.08 0.32 0.99 13.15 410 Table 55 . · SubJect 214 condition B. Time h:m:s 0:00:35 0:01:06 0:01:37 0:02:08 0:02:39 0:03:09 0:03:40 0:04:11 0:04:41 0:05:12 0:05:43 0:06:14 0:06:44 0:07:15 0:07:47 0:08:17 0:08:48 0:09:18 0:09:49 0:10:20 0:10:50 0:11 :21 0:11 :52 0:12:24 0:12:54 0:13:24 0:13:55 0:14:26 0:14:57 0:15:27 0:15:58 0:16:29 0:17:00 0:17:31 0:18:02 0:18:33 0:19:04 0:19:34 0:20:05 0:20:36 0:21:06 0:21 :37 o:22:08 0:22:39 0:23:09 02 % 17.37 17.18 16.49 16.27 16.19 16.3 16.3 16.43 16.27 16.34 16.3 16.52 16.47 16.45 16 15.78 15.61 15.61 16.08 15.87 15.78 15.94 15.81 15.71 15.69 15.71 15.86 15.9 15.96 15.74 15.79 15.84 15.74 15.79 15.83 15.77 15.87 15.94 15.87 16.25 16.47 16.99 17.38 17.57 17.66 0:23:40 17.45 0:24:10 0:24:41 17.1 17.01 2.2 2.45 2.62 2.64 2.68 2.65 2.67 2.63 2.73 2.72 2.75 2.64 2.66 2.61 2.82 2.84 2.92 2.91 2.8 2.9 2.9 2.85 2.9 2.92 2.91 2.92 2.9 2.92 2.89 2.94 2.94 2.9 2.9 2.89 2.9 2.93 2.92 2.93 2.9 2.81 2.69 2.46 2.31 2.24 2.16 2.15 2.23 2.49 Ve (Umin) 24.68 26.01 27.68 27.46 28.39 26.71 28.32 27,12 26.92 26.32 26.92 26.4 28.74 28.36 29.09 28.85 29.28 34.54 29.35 31.35 32.75 31.75 29.3 30.19 29.78 32.56 31.67 35.32 33.09 32.99 35.86 33.19 35.77 33.36 35.77 34.37 36.01 35.14 36.09 27.55 22.12 18.6 16.36 14.73 13.11 14.26 21.22 19.06 Vr (L) 0.59 0.7 1.11 1.1 0.79 0.92 1.13 1.17 1.01 1.08 1.06 1.2 1.09 1.26 1.07 0.98 1.33 1.28 1.04 1.36 1.22 1.22 1.37 1.49 1.36 1.22 1.47 1.07 1.18 1.12 1.38 1.12 1.24 1.38 1.37 1.44 1.13 1.34 1.31 1.05 0.64 0.63 0.57 0.49 0.45 0.41 0.61 Vo2 Vo2 (Umin) (mUkg/min) 0.97 12.59 1.07 1.37 1.43 1.5 1.38 1.46 1.36 1.39 1.34 1.38 1.29 1.42 13.85 17.71 18.53 19.52 17.9 18.97 17.6 18.07 17.38 17.95 16.75 18.42 1.41 18.32 HR (bpm) 90 89 84 87 89 87 104 1.6 20.75 1.66 21.58 98 1.75 22.66 2.06 26.7 100 1.59 20.57 1.77 22.94 101 1.88 24,44 1.77 22.91 100 1.68 21.74 22.88 22.64 1.76 1,75 1.9 24.67 23.21 1.79 1.98 25,64 1.83 23.71 1.91 24.78 2.06 26.68 1.89 24,46 2.07 26.91 1.91 24.83 2.04 26.4 1.98 25.68 2.03 26,3 1.95 25.26 2.04 26.4 1.43 18.52 1.09 14,17 0.81 10.46 o.64 8.24 7 0.54 o.47 6.07 0.55 7.09 o.9 11.72 o.82 10.66 411 100 99 106 113 108 111 111 113 110 RPE 6 6 7 7 7 8 8 8 Table 55. S . ubJect 214 condition B (cont.). Time h:m:s % 0:25:12 17.07 0:25:43 0:26:14 16.8 16.05 0:26:45 15.27 0:27:16 15.19 0:27:46 15.32 0:28:17 O 15.34 :28:48 15.43 0:29:19 15.63 0:29:49 15.49 0:30:20 15.38 0:30:51 15.55 0:31 :22 15.62 0:31 :53 15.81 0:32:23 15.68 0:32:54 15.83 0:33:25 16.06 0:33:56 16.18 0:34:27 0:34:58 0:35:28 0:35:59 0:36:30 0:37:01 0:37:32 0:38:02 0:38:34 0:39:04 0:39:35 0:40:05 0:40:36 0:41:07 0:41 :38 0:42:08 0:42:38 0:43:09 0:43:40 0:44:11 0:44:42 0:45:12 0:45:43 0:46:14 0:46:45 0:47:16 0:47:47 0:48:17 0:48:48 16.87 17.39 17.4 17.74 17.6 17.62 17.62 17.46 17.33 17.25 17.49 17.21 17.23 17.23 16.81 15.75 15.09 15.36 15.54 15.66 15.79 16.08 15.96 16.15 16.07 15.87 15.88 15.92 15.93 % 2.53 2.58 2.85 3.04 3.1 3.16 3.21 3.24 3.17 3.27 3.32 3.23 3.18 3.14 3.14 3.09 2.93 2.94 2.74 2.53 2.4 2.23 2.22 2.2 2.13 2.16 2.18 2.3 2.28 2.3 2.29 2.4 2.72 2.85 2.9 2.98 3.11 3.19 3.2 3.12 3.18 3.12 3.16 3.2 3.13 3.11 3.09 Ve (Umin) 23.14 25.43 30.89 35.97 38.38 43.73 41.39 44.48 43.07 41 .37 44.7 45.91 44.38 44.81 46.54 47.55 44.33 38.82 33.85 24.87 20.22 19.02 16.11 13.61 15.37 15.87 15.37 14.86 11.1 12.4 21.81 27.89 31.72 34.29 45.51 50.33 55.13 60.27 62.3 66.91 66.81 68.69 66.8 66.74 66.39 71.56 64.48 Vr Vo2 Vo2 HR (L) (Umin) (mUkg/min) (bpm) 0.8 0.98 12.67 15.01 21.73 29.66 0.88 1.19 1.24 1.92 1.75 1.97 1.85 2.05 2.43 2.03 2.19 1.78 1.72 2.12 1.76 2.02 1.85 1.3 0.99 0.7 0.59 0.54 0.31 o.33 0.34 0.37 0.29 0.22 o.35 0.7 0.93 1.17 1.27 1.9 2.4 2.21 2.74 2.71 3.04 2.9 2.75 2.67 2.67 2.66 2.98 2.8 1.16 1.68 2.29 2.48 2.74 2.58 2.72 2.53 2.49 2.75 2.74 2.61 2.53 2.71 2.68 2.39 2.03 1.49 0.95 0.78 o.66 0.58 0.49 0.56 0.61 0.61 o.6 0.42 0.51 0.89 1.13 1.43 1.99 3.01 3.15 3.31 3.51 3.53 3.56 3.64 3.59 3.55 3.71 3.7 3.95 3.56 412 32.1 35.52 33.42 35.22 32.82 32.34 35.61 35.47 33.83 32.86 35.1 34.8 30.97 26.35 19.38 12.33 10.06 8.5 7.59 6.39 7.23 7.86 7.94 7.82 5.4 6.59 11.53 14,66 18,5 25,85 39.07 40.88 42,91 45,59 45,8 46.12 47,19 46.52 46.1 48.14 47,93 51 .29 46,15 127 131 130 135 142 140 142 160 165 171 171 175 176 175 APE 11 11 12 13 14 15 Table 56 . · Subject 221 condition B. Time h:m:s 0:00:36 0:01:07 0:01 :38 0:02:09 0:02:39 0:03:09 0:03:41 0:04:11 0:04:42 o:05:1 2 0:05:43 0:06:14 0:06:45 0:07:16 0:07:47 0:08:18 0:08:48 0:09:19 0:09:49 0:10:21 0:10:51 0:11 :21 0:11 :52 0:12:23 0:12:54 0:13:25 0:13:56 0:14:27 0:14:58 0:15:28 0:15:59 0:16:30 o:11:00 0:17:31 0:18:02 0:18:32 0:19:04 0:19:34 0:00:35 0:01:07 0:01 :38 0:02:08 0:02:38 0:03:10 0:03:40 17.54 16.56 15.18 14.95 15.14 15.12 15.23 15.51 15.56 15.62 15.62 15.59 15.6 15.54 15.18 14.81 14.94 15.07 15.32 15.64 15.74 15.8 15.77 15.71 15.8 15.74 15.7 15.56 15.52 15.71 15.69 15.77 15.82 15.89 15.98 15.85 15.92 16.1 17.24 16.59 16.55 16.86 16.84 16.9 16.42 CO2 % 2.16 2.34 2.76 2.86 2.85 2.8 2.82 2.81 2.83 2.85 Ve (Umin) 15.13 17.26 19.1 19.78 18.67 20.94 20.79 20.62 20.7 20.03 Vr (L) 0.3 0.39 0.41 0.47 0.46 0.68 0.61 0.46 0.58 0.53 2.85 20.66 0.49 2.83 19.91 0.47 2.84 23.28 0.55 2.88 24.6 0.98 2.98 27.48 0.83 3.11 26.37 1.1 3.16 29.33 1.33 3.18 30.74 1.54 3.1 33.35 1.45 3.02 31.74 1.51 3 32.88 1.49 2.97 31.26 1.25 2.97 33.31 1.19 2.98 31.97 1.39 2.98 32.03 1.19 2.93 33.65 0.99 2.95 35.06 1.25 3.03 36.73 1.41 3.07 37.6 1.07 3.05 39.2 1.4 1.4 3.08 3.01 3.03 3.02 2.99 3.07 3 2.92 2.33 2.52 2.53 2.42 2.43 2.46 2.69 40.68 41.06 39.85 41.57 41.32 41.14 41.82 41.87 24 16.31 14.93 14,69 13.1 9.65 16.97 1.71 1.33 1.48 1.65 1.79 1.44 1.4 o.34 0.35 0.5 0.42 0.26 0.17 0.45 Vo2 Vo2 HR (Umin) (mUkg/min) (bpm) 0.56 7.51 0.85 1.25 1.35 1.23 1.38 1.35 1.26 1.25 1.2 1.23 1.2 1.4 1.49 1.79 1.83 1.98 2.02 2.1 1.87 1.9 1.79 1.92 1.86 1.83 1.95 2.05 2.2 2.27 2.27 2.37 2.35 2.26 2.32 2.26 2.31 2.32 2.24 0.97 o.79 o.73 o.66 o.59 o.43 o.85 413 11.31 16.66 17.99 16.39 18.46 17.94 16.82 16.69 15.95 16.46 15.95 18.6 19.9 23.81 24.36 26,38 26.97 27.94 24.96 25.33 23.8 25.56 24.79 24.4 25.98 27.28 29,34 30.26 30,31 31,56 31.39 30.11 30,96 30.15 30.83 30.93 29,83 12.99 10.51 9.71 8.85 7.93 5.73 11.31 94 88 87 95 100 112 115 117 119 119 120 133 138 139 144 144 142 RPE 10 10 10 11 12 12 12 12 12 · ubJect 221 condition B (cont.). Table 56 S . Time 02 h:m:s % 0:04:10 0:04:41 0:05:12 0:05:43 0:06:13 0:06:44 0:07:15 0:07:47 0:08:17 0:08:47 0:09:18 0:09:49 0:10:20 0:10:50 0:11 :21 0:11 :52 0:12:23 0:12:54 0:13:25 0:13:56 0:14:27 0:14:57 0:15:28 0:16:00 0:16:30 0:17:01 0:17:32 0:18:03 0:18:34 0:19:04 0:19:35 0:20:07 0:20:38 0:21 :08 0:21 :38 0:22:09 0:22:40 0:23:10 0:23:41 0:24:12 0:24:43 0:25:13 0:25:44 0:26:16 0:26:47 0:27:17 16.78 17.15 15.72 14.65 14.56 15.1 15.61 15.89 16.1 16. 19 16.23 16.13 16.12 16.13 16.21 16.12 16.27 16.77 17.21 17.34 17.15 17.03 17.13 17.26 17.12 16.83 17.18 16.54 16.69 16.96 17.09 17.22 17 .3 16.97 16.79 16.6 17.09 16.66 15.3 14.76 15.06 15.78 15.69 15.95 16.06 16.07 CO2 V V % ' r Va, Vo, HR APE (Umin) (L) (Umin) (mUkg/min) (bpm) 2·58 20.89 0.55 0.96 12.75 2.5 2.79 2.99 3.11 24.5 0.72 27.05 0.73 33.96 1.17 43.49 1.81 3.18 52.42 2.02 3.2 58.96 2.27 3.17 59.45 1.92 3.13 63.47 2.12 3.08 64.97 2.1 2.98 65.78 1.93 3.01 64.8 1.91 3.02 64.06 2 2.99 65.23 2.1 2.97 65.46 2.11 3 62.29 1.95 2.95 56.38 1.71 1.7 2.88 49.16 2.74 42.89 1.43 2.63 38.03 1.36 2.6 35.45 1.22 2.6 32.99 0.75 2.46 2.33 30.63 23.49 23.66 0.65 0.55 2.29 2.36 25.51 0.98 2.28 21 .19 0.56 2.4 19.71 0.9 2.43 17.98 0.58 2.39 18.1 0.6 2.38 17.13 0.45 2.34 15.65 0.36 2.32 13.46 0.52 2.39 14.16 0.43 2.39 11.19 0.25 2.48 19.06 0.56 2.31 21.95 0.58 2.44 26.82 0.71 31 .7 1.17 2.64 2.78 42.36 1.37 2.84 56.73 1.89 2.88 61.89 1.77 3.01 60.58 1.89 63.65 1.99 3.01 2.99 61.49 1.76 2.95 63.59 2.12 1.01 1.58 2.43 3.15 3.42 3.47 3.3 3.36 3.37 3.4 3.43 3.39 3.45 3.4 3.3 2.89 2.21 1.71 1.46 1.45 1.4 1.27 0.95 1.17 0.88 0.97 0.85 0.8 o.73 0.64 0.54 0.62 0.52 0.92 0.93 1.28 2.04 3 3.79 3.56 3.53 3.51 3.31 3.42 414 13.5 21.11 32.42 41.98 45.66 46.32 43.98 44.78 44.93 45.29 45.67 45.2 45.96 45.36 43.94 38.54 29.5 22.8 19.51 19.36 18.69 16.98 12.62 13.32 15.54 11.73 12.95 11.33 10.61 9.67 8.51 7.16 8.27 6.87 12.28 12.46 17,03 27,16 39,99 50.53 47,53 47,13 46,74 44,08 45,58 173 179 181 186 189 188 179 181 182 181 14 15 15 15 · ubJect 221 condition B (cont.). Table 56 S . Time 02 h:m:s CO2 VE Vr Vo2 Vo2 HA APE 0:27:47 % % (Umin) (L) (Umin) (mUkg/min) (bpm) 16.01 0:28:18 2.95 64.02 2.07 3.49 46.52 182 16 0:28:49 16.1 2.9 63.78 1.64 3.41 45.48 0:29:20 16.07 2.88 63.05 1.66 3.4 45.33 190 0:29:50 16.01 2.9 63.04 1.43 3.44 45.93 0:30:21 16 2.91 64.98 1.76 3.56 47.46 187 18 16.08 2 .87 34.17 0.85 1.84 24.52 0:00:35 16.14 3.06 0:01:06 55.08 1.67 2.9 38.64 0:01 :38 16.24 3.38 65.86 2.35 3.32 44.26 177 0:02:08 16.7 3.48 73.61 2.45 3.26 43.51 0:02:39 16.85 3.49 79.86 2.16 3.39 45.18 183 17 0:03:10 17 3.44 77.63 2.1 3.15 42.06 0:03:40 17.01 3.44 80.02 2.29 3.25 43.27 187 0:04:11 17.02 3.39 85.92 2.26 3.49 46.52 0:04:42 16.98 3.36 84.27 2.28 3.46 46.2 189 19 0:05:13 17.05 3.36 86.38 2.16 3.48 46.42 0:05:44 17.11 3.49 87.42 2.24 3.42 45.57 193 0:06:15 17.17 3.44 89.57 2.13 3.45 46.03 194 19 17.09 3.46 69.15 1.36 2.73 36.45 415 Table 57 S . · ubJect 231 condition B. Time h:m:s 0:00:36 0:01:06 0:01:37 0:02:09 0:02:39 0:03:09 0:03:40 0:04:11 0:04:42 0:05:13 0:05:43 0:06:15 0:06:45 0:07:16 0:07:47 0:08:18 0:08:48 0:09:19 0:09:50 0:10:21 0:10:52 0:11 :23 0:11 :53 0:12:24 0:12:55 0:13:26 0:13:56 0:14:27 0:14:58 0:15:28 0:15:59 0:16:30 0:17:01 0:17:31 0:18:02 0:18:33 0:19:04 0:19:34 0:20:05 0:20:36 0:21 :07 0:00:36 0:01 :07 0:01 :38 0:02:08 0:02:39 0:03:10 18.45 18.12 18.08 18.07 18.01 17.9 17.93 18.09 17.92 17.83 17.82 17.86 17.91 18.16 18.1 17.57 17.53 17.4 17.37 17.58 17.61 17.5 17.57 17.58 17.59 17.55 17.55 17.48 17.34 17.33 17.38 17.25 17.34 17.37 17.4 17.38 17.35 17.46 17.43 17.63 17.7 18.09 17.97 17.8 17.83 18.02 18.12 CO2 VE Vr Vo2 Vo2 (Umin) (L) (Umin) (mUkg/min) % 1.88 1.99 2.01 2.03 2.01 2.02 1.99 14.41 0.66 0.38 6.18 14.84 0.42 0.45 7.3 16.44 0.69 13.91 0.38 14.31 0.33 18.02 0.82 13.59 0.4 1.93 15.16 0.61 1.99 1.99 1.98 2.01 1.98 1.9 1.92 2.11 14.27 0.59 15.98 0.55 14.7 0.4 15.32 0.53 15.04 0.38 14.15 0.38 17.1 0.45 19.41 0.55 2.13 18.99 0.65 2.19 20.09 0.63 2.16 20.08 0.59 2.11 2.1 2.17 20.85 0.74 20.48 0.66 19.42 0.65 2.14 19.82 0.55 2.15 20.47 0.55 2.16 2.17 19 0.53 19.85 0.66 2.18 21.59 0.67 2.18 21.07 0.73 2.24 23.06 0.72 2.22 22.43 o.64 2.23 23.8 0.88 2.25 22.83 0.71 2.22 22.77 0.73 2.24 22.3 0.62 2.25 23.39 0.69 2.27 23.09 0.77 2.22 24.17 0.93 2.21 23.06 0.72 2.2 24.52 0.82 2.17 21.63 0.66 2.16 16.23 0.36 2.06 11.37 0.32 2.02 11.54 0.24 2.06 12.23 0.24 2.04 2.05 2.01 12.68 0.33 12.94 0.35 17.11 0.45 0.51 0.43 0.45 0.6 0.44 0.47 0.47 0.54 0.5 0.51 0.5 0.43 0.53 0.72 0.71 0.78 0.79 0.77 0.75 0.73 0.73 o.75 0.7 0.74 0.8 0.8 0.91 0.89 0.93 0.93 0.9 0.87 0.91 0.9 0.95 0.88 0.94 0.78 0.57 0.35 0.37 0.42 o.43 o.41 o.52 416 8.22 6.97 7.35 9.65 7.2 7.58 7.62 8.8 8.13 8.33 8.04 6.91 8.53 11.62 11.53 12.69 12.83 12.47 12.11 11.87 11.84 12.21 11.28 11,95 12.97 12.95 14.77 14.43 15.09 15.03 14.6 14.17 14,73 14.59 15.45 14.23 15.3 12.64 9.25 5.63 6.01 6.79 6.96 6.6 8.41 HR (bpm) 82 86 79 86 80 86 86 82 84 86 87 119 119 117 117 118 APE 7 7 7 7 7 7 9 9 10 Table 57 · Subject 231 condition B (cont.). Time 0 2 CO2 Ve Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:03:41 18.09 2.05 21.87 0.71 0.67 10.83 0:04:11 17.67 2.18 21.8 0.66 0.78 12.58 0:04:42 17 2.31 26.84 0.75 1.17 18.98 115 0:05:13 16.87 2.33 29.92 1.35 21.93 0:05:44 16.78 2.37 29.94 0.79 1.39 22.45 117 0:06:14 16.77 2.44 33.84 1.13 1.56 25.32 13 0:06:45 17.08 2.42 33.3 1.01 1.41 22.84 116 0:07:16 17.01 2.48 33.65 1.12 1.45 23.49 0:07:47 17.12 2.47 35.04 1.13 1.46 23.68 117 0:08:18 17.18 2.48 33.26 0.74 1.36 22.04 14 0:08:49 17.01 2.56 35.94 1.12 1.54 24.97 121 0:09:19 17.27 2.48 35.28 1.1 1.4 22.76 0:09:49 17.29 2.45 36.22 1.01 1.43 23.25 121 0:10:21 17.21 2.42 35.07 1.13 1.43 23.13 14 0:10:51 17.19 2.44 33.52 0.91 1.37 22.26 0:11 :22 17.29 2.4 30.12 0.89 1.2 19.43 0:11 :53 17.5 2.33 22.12 0.51 0.83 13.37 0:12:24 17.75 2.31 3.78 0.11 0.13 2.09 0:12:55 17.7 2.34 3.8 0.18 0.13 2.14 0:13:26 17.73 2.36 3.75 0.1 0.13 2.08 0:13:58 17.73 2.35 3.51 0.13 0.12 1.95 0:14:28 17.76 2.34 3.75 0.09 0.13 2.07 0:14:59 17.76 2.31 3.71 0.18 0.13 2.05 0:15:30 17.75 2.28 3.87 0.09 0.13 2.15 0:16:01 17.79 2.28 3.84 0.13 0.13 2.1 0:16:31 17.82 2.27 3.7 0.11 0.12 2 0:17:02 17.87 2.27 3.84 0.1 0.13 2.04 0:17:34 17.88 2.26 3.71 0.15 0.12 1.97 0:18:05 17.9 2.24 3.69 0.17 0.12 1.94 0:18:36 18.1 4.33 0.12 0.13 2.13 2.08 0:19:07 18.74 3.94 0.12 0.09 1.49 1.69 0:19:37 19.14 7.71 0.2 0.15 2.36 1.45 0:20:08 18.74 12.97 0.36 0.3 4.92 1.63 0:20:39 9.95 0.2 0.28 4.55 18.3 1.94 0:21 :10 10.3 0.25 0.28 4.55 18.37 1.94 0:21:40 18.08 10.26 0.23 0.32 5.13 2.01 7.37 0:22:11 17.51 0.45 o.45 18.52 1.73 11.05 0:22:42 18.04 21.79 0.68 0.68 2 15.19 0:23:13 24.83 0.71 0.94 17.48 2.24 22.26 118 0:23:44 29.2 0.91 1.37 16.73 2.34 25,61 0:24:14 32.03 0.84 1.58 16.53 2.39 27,79 124 0:24:45 34.07 1.06 1.71 16.46 2.4 29,98 15 0:25:16 37.69 1.11 1.85 16.53 2.53 26,89 0:25:47 1.07 1.66 16.82 2.53 36.53 28,85 0:26:17 16.79 2.6 39.02 1.15 1.78 135 0:26:47 39.74 1.24 1.79 29,04 16.82 2.65 29,03 15 0:27:19 16.94 2.66 41 .16 1.14 1.79 417 Table 57. Subject 231 condition B (cont.). Time 02 CO2 h:m:s VE Vr Vo2 Vo2 HR APE 0:27:49 % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:28:20 16.89 2.66 40.53 1.19 1.79 28.96 134 0:28:51 17.09 2.6 40.07 1.11 1.67 27.13 134 0:29:22 16.96 2.64 39.67 0.97 1.72 27.89 136 17 2.59 40.54 1.1 1.74 28.19 139 15 418 Table 58. Subject 001 condition C. Time Vr Vo2 Vo2 HR APE 02 CO2 Ve h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:00:37 17.84 2 .18 21.41 0.76 0.72 7.78 0:01:06 1.17 0.78 8.44 65 17.56 2.26 21.15 0:01 :37 16.55 2.54 22.53 1.02 1.1 11.95 11.44 71 6 0:02:09 16.49 2.61 21.33 0.82 1.05 0:02:39 22.55 0.87 1.16 12.61 16.32 2.63 11.99 65 0:03:10 0.92 1.1 16.42 2.6 21.97 12.57 0:03:40 23.85 0.95 1.16 16.57 2.56 12.24 65 6 0:04:11 16.53 2.58 23.02 0.92 1.13 0:04:42 23.93 0.96 1.13 12.33 16.66 2.54 12.03 70 0:05:13 16.69 2.54 23.57 1.07 1.11 0:05:44 0.89 1.22 13.25 16.64 2.58 25.67 13.35 66 6 0:06:15 16.86 2.51 27.34 1.01 1.23 13.45 0:06:45 17.02 2.46 28.76 1.07 1.24 15.73 0:07:16 17.04 2.47 33.88 1.13 1.45 6 14.94 82 0:07:47 17.18 2.44 33.46 1.12 1.37 16.01 0:08:17 16.93 2.51 33.43 1.19 1.47 6 16.85 0:08:48 16.68 2.56 32.97 1.18 1.55 17.91 0:09:18 16.79 2.57 36.12 1.17 1.65 85 16.54 0:09:49 17.13 2.51 36.67 1.18 1.52 1.38 14.97 0:10:20 17.12 2.48 33.06 1.18 16.8 84 6 0:10:51 16.81 2.54 33.95 1.13 1.55 1.44 15.61 0:11 :21 16.89 2.49 32.22 1.11 18.04 84 0:11 :53 16.76 2.54 36 1.24 1.66 1.5 16.33 0:12:24 17.06 2.49 35.35 1.22 16.91 85 6 1.56 0:12:54 16.87 2.53 34.83 1.55 16.89 0:13:25 16.95 2.48 35.43 1.07 19 0:13:55 17.01 2.48 40.55 1.31 1.75 95 1.89 20.49 0:14:26 16.9 2.54 42.48 1.37 20.34 0:14:57 40.66 1.31 1.87 94 7 16.77 2.54 1.97 21.36 0:15:27 41.73 1.3 16.67 2.57 1.92 20.83 0:15:58 16.73 2.55 41.19 1.29 21.55 96 0:16:29 41.29 1.38 1,98 22.12 16.61 2.55 2.03 0:17:00 16.55 2.57 41.85 1.35 20.39 92 7 0:17:31 40.46 1.31 1.88 20.29 16.74 2.55 1.87 0:18:03 16.56 2.58 38.49 1.17 22.43 100 0:18:33 41.03 1.28 2.06 22.21 16.41 2.64 2.04 0:19:03 41.46 1.34 20.8 9 16.49 2.63 1.91 0:19:35 39.86 1.33 21.91 16.59 2.64 2.02 0:20:05 43.12 1.35 24,86 16.69 2.62 2.29 0:20:35 49.56 1.42 25,2 16.75 2.56 2.32 0:21 :06 52.26 1.54 30.07 122 16.89 2.57 2.77 0:21 :37 16.45 2.68 55.74 1.59 31,75 0:22:08 56.12 1.65 2.92 32.92 124 11 16.24 2.8 3.03 0:22:39 16.24 2.81 58.32 1.67 33,7 3.1 0:23:10 16.3 2.82 60.56 1.68 33,83 125 3.11 0:23:41 16.37 2.78 61.76 1.54 419 Table 58. Subject 001 condition C (cont.). Time 02 CO2 Ve Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:24:11 16.42 2.73 64.15 1.73 3.2 34.78 0:24:42 16.41 2.76 65.69 1.64 3.28 35.64 130 12 0:25:13 16.62 2.67 66.3 1.54 3.15 34.23 0:25:43 16.67 2.67 66.9 1.59 3.13 34.07 134 0:26:14 16.67 2.66 64.71 1.54 3.04 33.04 0:26:44 16.52 2.72 67.24 1.49 3.27 35.59 135 0:27:15 16.63 2.67 68.93 1.44 3.27 35.52 0:27:46 16.72 2.64 69.43 1.48 3.22 34.95 0:28:17 16.64 2.67 74.44 1.52 3.52 38.23 148 0:28:48 16.6 2.72 78.82 1.61 3.76 40.85 0:29:19 16.55 2.79 80.34 1.67 3.86 41.94 150 15 0:29:50 16.59 2.8 81 .26 1.63 3.87 42.04 0:30:20 16.64 2.8 82.51 1.65 3.87 42.1 155 0:30:51 16.68 2.81 86.92 1.58 4.03 43.81 0:31 :21 16.68 2.81 84.57 1.57 3.92 42.62 158 17 0:31:52 16.49 2.88 87.95 1.47 4.27 46.46 420 Table 59 S . · ubJect 002 condition C. Time h:m:s 0:00:36 0:01 :06 0:01 :38 0:02:08 0:02:40 0:03:10 0:03:40 0:04:12 0:04:42 0:05:13 0:05:44 0:06:14 0:06:45 0:07:16 0:07:47 0:08:17 0:08:48 0:09:19 0:09:50 0:10:21 0:10:51 0:11 :22 0:11 :53 0:12:24 0:12:54 0:13:25 0:13:56 0:14:26 0:14:58 0:15:28 0:15:59 0:16:30 0:17:01 0:17:32 0:18:03 0:18:33 0:19:04 0:19:35 0:20:05 0:20:36 0:21 :06 0:21 :37 0:22:08 0:22:39 0:23:10 0:23:40 16.97 17.26 17.32 17.41 17.12 17 16.91 16.95 17.06 17.04 16.98 16.99 17.05 16.96 16.84 16.86 16.65 16.43 16.48 16.67 16.82 16.75 16.64 16.47 16.73 16.77 16.54 16.69 16.55 16.45 16.37 16.49 16.34 16.51 16.54 16.44 16.35 16.41 16.55 16.64 16.65 16.59 16.58 16.83 16.68 16.78 CO2 % 2.22 2.15 2.15 2.12 2.13 2.1 2.13 2.06 2.02 2.04 2.11 2.11 2.07 2.09 2.16 2.22 2.23 2.28 2.3 2.28 2.27 2.3 2.3 2.32 2.25 2.22 2.27 2.28 2.33 2.33 2.4 2.34 2.41 2.35 2.36 2.38 2.41 2.43 2.37 2.37 2.43 2.47 2.44 2 .37 2.41 2.39 Ve Vr (Umin) (L) 12.33 0.32 11.02 0.26 10.6 0.19 10.32 0.21 10.48 0.24 10.8 0.31 11.46 0.22 12.38 0.29 11.26 0.25 10.58 0.22 10.95 0.23 12.34 0.33 12.97 0.25 16.08 0.39 16.44 0.46 13.45 0.25 16.49 0.31 16.22 0.54 16.77 0.45 15.49 0.62 14.83 0.53 15.17 0.43 14.35 0.38 16.44 0.43 14.61 0.37 15.99 0.37 19.96 0.57 19.56 0.65 20.85 0.61 19.64 0.63 20.41 0.66 20 0.56 20.97 o.7 21 .13 o.48 19.87 0.48 21.68 0.5 19.88 0.45 20.96 0.52 24.95 0.76 26.07 0.74 28.42 1.02 28.1 0.88 32.37 0.98 31.46 0.9 31.24 0.78 30.9 0.81 Vo2 Vo2 (Umin) (mUkg/min) 0.55 9.42 0.45 0.42 0.4 0.45 0.48 0.52 0.56 0.49 0.46 0.49 0.55 0.57 0.72 0.76 0.61 0.8 0.83 0.84 0.74 0.68 0.71 0.69 0.83 0.69 o.75 0.99 0.93 1.03 0.99 1.05 1,08 1.05 0.98 1.1 1.03 1.06 1.23 1.25 1,36 1.36 1.57 1.44 1.48 1.43 421 7.74 7.33 6.94 7.7 8.24 8.96 9.59 8.48 8 8.39 9.44 9.76 12.41 13.06 10.6 13.73 14.25 14.53 12.81 11 .77 12.26 11.95 14.26 11.9 12.89 17.04 16.06 17.7 17.12 18.11 17.24 18.7 18.16 16.92 18.93 17,67 18.35 21.15 21.61 23,39 23.45 21.12 24,74 25,53 24,62 HR (bpm) 90 101 102 95 100 103 100 96 93 98 99 94 98 97 95 96 97 98 91 96 94 92 98 108 115 101 108 109 97 109 106 112 112 112 111 128 135 137 138 138 140 142 APE 9 9 9 11 11 11 11 11 11 13 Table 59. Subject 002 condition C (cont.). Time 02 CO2 VE Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L} (Umin) (mUkg/min) (bpm} 0:24:11 16.79 2.43 31.5 0.9 1.45 25.01 141 0:24:42 16.81 2.43 29.36 0.65 1.34 23.18 144 0:25:13 16.67 2.48 33.41 0.78 1.58 27.3 141 0:25:44 16.92 2.41 31.16 0.68 1.38 23.86 140 0:26:14 16.83 2.44 30.73 0.75 1.4 24.09 13 0:26:45 16.74 2.45 33.01 0.75 1.54 26.53 149 0:27:17 16.87 2.39 35.95 0.88 1.62 27.94 0:27:47 17.02 2.36 34.97 0.71 1.51 26.07 149 0:28:17 16.88 2.42 36.13 0.98 1.62 28 156 0:28:48 16.96 2.42 38.23 0.87 1.68 28.92 154 0:29:19 17 2.4 37.69 0.99 1.64 28.25 155 15 0:29:50 17.1 2.43 37.82 1 1.59 27.45 155 0:30:21 17.05 2.4 37.92 0.9 1.62 27.99 153 0:30:51 17.09 2.36 36.47 0.87 1.54 26.63 156 0:31 :22 16.94 2.37 37.1 0.93 1.64 28.31 158 0:31 :53 16.97 2.35 33.6 0.65 1.48 25.49 150 0:32:24 16.62 2.41 37.33 0.93 1.8 31.02 149 0:32:54 16.7 2.41 36.91 0.84 1.74 30.03 153 15 0:33:25 16.9 2.38 37.73 0.84 1.69 29.13 0:33:56 16.98 2.35 20.38 0.39 0.89 15.38 422 Table 60 . · SubJect 023 condition C. Time 02 h:m:s % 0:00:36 0:01:06 0:01 :38 0:02:08 0:02:40 0:03:10 0:03:40 0:04:12 0:04:42 0:05:13 0:05:44 0:06:14 0:06:45 0:07:16 0:07:47 0:08:17 0:08:48 0:09:19 0:09:50 0:10:21 0:10:51 0:11 :22 0:11 :53 0:12:24 0:12:54 0:13:25 0:13:56 0:14:26 0:14:58 0:15:28 0:15:59 0:16:30 0:17:01 0:17:32 0:18:03 0:18:33 0:19:04 0:19:35 0:20:05 0:20:36 0:21 :06 0:21:37 0:22:08 0:22:39 0:23:10 0:23:40 16.97 17.26 17.32 17.41 17.12 17 16.91 16.95 17.06 17.04 16.98 16.99 17.05 16.96 16.84 16.86 16.65 16.43 16.48 16.67 16.82 16.75 16.64 16.47 16.73 16.77 16.54 16.69 16.55 16.45 16.37 16.49 16.34 16.51 16.54 16.44 16.35 16.41 16.55 16.64 16.65 16.59 16.58 16.83 16.68 16.78 CO2 V E Vr Vo2 Vo 2 % (Umin) (L) (Umin) (mUkg/min) 2.22 12.33 0.32 0.55 9.42 0.45 7.74 2.15 11.02 0.26 2.15 2.12 2.13 2.1 2.13 2.06 2.02 2.04 2.11 2.11 2.07 2.09 2.16 2.22 2.23 2.28 2.3 2.28 2.27 2.3 2.3 2.32 2.25 2.22 2.27 2.28 2.33 2.33 2.4 2.34 2.41 2.35 2.36 2.38 2.41 2.43 2.37 2.37 2.43 2.47 2.44 2.37 2.41 2.39 10.6 0.19 10.32 0.21 10.48 0.24 10.8 0.31 11.46 0.22 12.38 0.29 11.26 0.25 10.58 0.22 10.95 0.23 12.34 0.33 12.97 0.25 16.08 0.39 16.44 0.46 13.45 0.25 16.49 0.31 16.22 0.54 16.77 0.45 15.49 0.62 14.83 0.53 15.17 0.43 14.35 0.38 16.44 0.43 14.61 0.37 15.99 0.37 19.96 o.57 19.56 0.65 20.85 0.61 19.64 0.63 20.41 0.66 20 0.56 20.97 0.7 21 .13 0.48 19.87 o.48 21.68 0.5 19.88 0.45 20.96 0.52 24.95 0.76 26.07 0.74 28.42 1.02 28.1 0.88 32.37 0.98 31.46 0.9 31.24 0.78 30.9 0.81 0.42 0.4 0.45 0.48 0.52 0.56 0.49 0.46 0.49 0.55 0.57 0.72 0.76 0.61 0.8 0.83 0.84 o.74 0.68 0.71 0.69 0.83 0.69 0.75 0.99 0.93 1.03 0.99 1.05 1.08 1.05 0.98 1.1 1.03 1.06 1.23 1.25 1.36 1.36 1.57 1.44 1.48 1.43 423 7.33 6.94 7.7 8.24 8.96 9.59 8.48 8 8.39 9.44 9.76 12.41 13.06 10.6 13.73 14.25 14.53 12.81 11.77 12.26 11.95 14.26 11.9 12.89 17.04 16.06 17.7 17.12 18.11 17.24 18.7 18.16 16.92 18.93 17.67 18.35 21.15 21.61 23.39 23.45 27.12 24.74 25,53 24,62 Table 60. Subject 023 condition C (cont.). Vr Vo2 Vo2 Time 02 CO2 Ve (mUkg/min) h:m:s (Umin) (L) (Umin) % % 1.45 25.01 0:24:11 2.43 31.5 0.9 16.79 1.34 23.18 0:24:42 16.81 2.43 29.36 0.65 27.3 0:25:13 2.48 33.41 0.78 1.58 16.67 1.38 23.86 0:25:44 31.16 0.68 16.92 2.41 1.4 24.09 0:26:14 16.83 2.44 30.73 0.75 26.53 1.54 0:26:45 16.74 2.45 33.01 0.75 27.94 1.62 0:27:17 16.87 2.39 35.95 0.88 26.07 0:27:47 34.97 0.71 1.51 17.02 2.36 1.62 28 0:28:17 16.88 2.42 36.13 0.98 28.92 1.68 0:28:48 16.96 2.42 38.23 0.87 28.25 1.64 0:29:19 17 2.4 37.69 0.99 27.45 0:29:50 37.82 1 1.59 27.99 17.1 2.43 1.62 0:30:21 37.92 0.9 26.63 17.05 2.4 1.54 0:30:51 36.47 0.87 28.31 17.09 2.36 1.64 0:31 :22 16.94 2.37 37.1 0.93 25.49 1.48 0:31:53 16.97 2.35 33.6 0.65 1.8 31.02 0:32:24 16.62 2.41 37.33 0.93 1.74 30,03 0:32:54 16.7 2.41 36.91 0.84 29.13 1.69 0:33:25 16.9 2.38 37.73 0.84 15.38 0.89 0:33:56 16.98 2.35 20.38 0.39 424 Table 61 . · SubJect 145 condition C. Time 02 h:m:s % 0:00:36 0:01 :07 0:01 :37 0:02:08 0:02:39 0:03:09 0:03:40 0:04:11 0:04:42 0:05:13 0:05:44 0:06:14 0:06:45 0:07:16 0:07:47 0:08:17 0:08:48 0:09:19 0:09:49 0:10:20 0:10:51 0:11 :21 0:11 :53 0:12:24 0:12:54 0:13:25 0:13:56 0:14:26 0:14:56 0:15:28 0:15:58 0:16:29 0:17:00 0:17:31 0:18:01 0:18:33 0:19:04 0:19:34 0:20:05 0:20:36 0:21:06 0:21:37 0:22:08 0:22:39 0:23:09 0:23:40 17.62 17.19 17.21 17.06 17.27 17.1 17.21 17.68 17.67 17.31 17.25 17.14 17.18 17.26 17.31 17.34 17.31 17.27 17.23 16.8 17.12 17.09 16.84 17.08 17.13 17.2 16.72 17.09 16.96 17.54 17.6 16.59 17.03 17.09 17.08 16.95 16.75 16.64 16.83 16.88 17.12 17.27 17.74 17.01 17.12 17.03 Ve Vr Vo2 Vo2 % (Umin) (L) (Umin) (mUkg/min) 2.02 24.44 0.72 0.89 9.72 10.91 2.23 24.17 0.59 2.24 2.27 2.22 2.18 2.16 2.05 2.13 2.16 2.19 2.26 2.21 2.23 2.23 2.2 2.19 2.21 2.2 2.34 2.31 2.31 2.33 2.3 2.28 2.23 2.36 2.31 2.34 2.15 2.11 2.36 2.25 2.29 2.27 2.35 2.37 2.42 2.36 2.35 2.3 2.21 2.1 2.32 2.31 2.35 24.03 0.57 26.89 0.77 24.36 0.41 27.32 0.72 31.32 0.82 29.14 0.79 23.38 0.53 26.36 0.69 23.96 0.75 24.98 0.93 26.93 0.61 28.41 0.98 28.76 0.74 30.69 0.83 29.02 0.97 30.44 0.9 25.31 0.59 31.25 0.92 28.88 0.66 26.49 0.59 28.73 0.82 28.93 0.78 28.66 0.61 27.7 0.75 33.45 0.9 36.08 43.46 1.11 47.18 1.15 32,64 0.73 39.58 0.97 41.63 0.97 39.85 0.87 37.74 0.97 36.65 0.94 35.67 0.89 37.76 1.08 37.05 1.2 43,04 1.16 49.61 1.06 66.04 1.57 52.09 1.13 55.37 1.46 56.7 1.38 58,8 1.37 0.99 1.16 0.99 1.17 1.3 1.04 0.83 1.06 0.98 1.05 1.12 1.15 1.15 1.22 1.16 1.24 1.04 1.44 1.22 1.13 1.31 1.24 1.21 1.15 1.57 1.54 1.92 1.76 1.2 1.93 1.81 1.7 1.62 1.62 1.66 1.81 1.69 1.94 2.09 2.67 1.81 2.41 2.39 2.54 425 10.77 12.56 10.73 12.7 14.11 11.34 9.04 11.49 10.63 11.41 12.2 12.52 12.5 13.21 12.65 13.43 11.3 15.67 13.22 12.24 14.25 13.43 13.12 12.45 17.11 16.69 20.82 19.13 13 20.94 19.63 18.45 17.56 17,6 18.09 19.65 18.38 21.1 22.72 29,06 19.72 26.2 25,95 27,58 HR (bpm) 80 74 85 82 82 85 87 95 92 90 90 86 95 105 101 104 107 105 105 105 114 124 128 124 RPE 7 7 7 11 11 11 12 12 12 13 Table 61. Subject 145 condition C (cont.). Time 02 CO2 VE Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:24:11 17.34 2.27 54.7 1.24 2.16 23.47 133 13 0:24:42 17.07 2.32 54.71 1.33 2.34 25.41 131 0:25:13 17.05 2.33 64.97 1.71 2.79 30.32 136 0:25:44 17.75 2.1 63.18 1.5 2.2 23.89 132 0:26:15 17.3 2.16 61.25 1.39 2.46 26.77 137 13 0:26:45 17.35 2.16 53.83 1.45 2.13 23.19 0:27:17 16.81 2.34 51.07 1.09 2.35 25.55 0:00:35 16.76 2.25 51.63 1.08 2.42 26.31 0:01 :06 16.66 2.31 59.51 1.42 2.85 31 146 0:01 :37 16.9 2.35 69.86 1.52 3.13 34.06 0:02:07 17.23 2.3 74.2 1.65 3.03 32.91 154 14 0:02:38 17.38 2.27 77.41 1.68 3.01 32.77 0:03:09 17.3 2.3 77.78 1.53 3.1 33.71 152 0:03:40 17.22 2.33 77.21 1.61 3.15 34.29 0:04:11 17.38 2.29 86.39 1.6 3.36 36.56 160 14 0:04:42 17.44 2.26 84.31 1.65 3.22 35.01 0:05:12 17.41 2.24 84.18 1.72 3.25 35.35 161 0:05:44 17.44 2.27 87.06 1.78 3.33 36.19 0:06:14 17.44 83.43 1.7 3.19 34.69 162 16 2.27 0:06:45 17.4 2.3 45.3 0.89 1.75 19.01 426 Table 62 S . · ubJect 173 condition C. Time 02 h:m:s % 0:00:35 0:01 :06 0:01:37 0:02:08 0:02:38 0:03:09 0:03:40 0:04:11 0:04:42 0:05:13 0:05:44 0:06:14 0:06:45 0:07:16 0:07:46 0:08:17 0:08:48 0:09:19 0:09:49 0:10:20 0:10:51 0:11 :22 0:11 :53 0:12:23 0:12:55 0:13:25 0:13:56 0:14:27 0:14:58 0:15:28 0:15:59 0:16:30 0:17:01 0:17:31 0:18:02 0:18:33 0:19:03 0:19:34 0:20:06 0:20:36 0:21:07 0:21:37 0:22:08 0:22:39 0:23:10 0:23:41 18.32 17.76 17.14 16.86 16.89 16.78 16.84 16.85 16.72 16.94 16.78 16.96 17 16.88 16.68 16.41 16.31 16.25 16.23 16.27 16.42 16.4 16.32 16.24 16.36 16.47 16.61 16.82 16.51 16.5 16.55 16.55 16.59 16.55 16.64 16.64 16.54 16.51 16.39 16.49 16.85 17.08 17.46 17.88 17.93 18.19 % 2.05 2.24 2.39 2.45 2.44 2.47 2.44 2.44 2.47 2.38 2.45 2.45 2.43 2.48 2.62 2.7 2.73 2.77 2.79 2.82 2.79 2.81 2.8 2.86 2.84 2.81 2.73 2.65 2.76 2.81 2.8 2.82 2.79 2.78 2.79 2.78 2.81 2.82 2.86 2.82 2.7 2.63 2.47 2.32 2.3 2.15 VE (Umin} 15.46 Vr (L} 0.4 17.72 0.52 17.89 0.72 17.87 0.64 17.99 0.58 17.65 0.68 18.88 0.65 17.05 0.43 19.16 0.49 18.37 0.63 19.57 0.67 19.56 0.49 21.21 0.66 21.92 0.78 21.93 0.84 22.37 1.18 19.97 0.91 21.1 1.24 22.5 1.13 21.87 1.09 20.59 0.86 21,3 0.93 22.13 1.05 22.67 1.74 21.52 0.98 23.53 1.02 29.25 1.12 27,36 1.52 30.98 1.41 29.85 1.42 28,33 1.49 30 1.36 30.11 1.31 30.12 1.26 32.3 1.54 29.37 1.63 30,8 1.47 28.34 1.42 31.52 1.58 24.28 1.16 23.07 0.82 17.06 0.45 16.3 0.47 15,57 0.62 13,3 0.53 8.89 0.27 Vo2 Vo2 (Umin} (mUkg/min} 0.43 6.59 0.61 0.75 0.8 0.8 0.81 0.86 o.77 0.9 0.81 0.9 0.86 0.92 0.98 1.03 1.12 1.02 1.1 1.17 1.13 1.02 1.06 1.13 1.17 1.08 1.16 1.39 1.23 1.51 1.45 1.36 1.44 1.43 1.45 1.51 1.38 1.48 1.38 1.57 1.18 1.03 0.11 0.61 o.51 o.42 0.26 427 9.34 11.49 12.38 12.38 12.49 13.15 11.87 13.8 12.49 13.86 13.19 14.14 15.11 15.83 17.25 15.74 16.87 18.05 17.36 15.75 16.35 17.35 18.06 16.65 17.77 21.38 18.97 23.22 22.38 20.95 22.14 22.03 22.29 23,3 21.21 22.83 21.17 24,18 18.22 15,82 10.99 9.39 7.78 6.54 3.97 HR (bpm} 90 85 88 85 82 84 98 99 92 98 98 99 100 113 109 113 112 107 113 RPE 6 6 6 7 8 8 9 10 10 · ubJect 173 condition C (cont.). Table 62 s . Time h:m:s 0:24:11 0:24:42 0:25:13 0:25!44 0:26:15 0:26:46 0:27:16 0:27:47 0:28:18 0:28:49 0:29:20 0:29:50 0:30:21 0:30:52 0:31 :23 0:31 :54 0:32:24 0:32:55 0:33:26 0:33:56 0:34:27 0:34:58 0:35:29 02 % 17.91 17.58 17.73 17.23 16.42 16.51 16.66 16.83 16.84 16.73 16.8 16.84 16.89 16.75 16.84 16.61 16.63 16.74 16.79 17 17.26 17.4 17.7 0:36:00 17.57 0:36:30 17.57 0:37:01 17 .58 0:37:32 17.56 0:38:04 17 .59 0:38:34 18.13 0:39:05 18.22 0:39:35 0:40:06 0:40:37 0:41:07 0:41 :38 0:42:09 18.18 17.5 17.15 16.96 17.02 17.17 o:42:40 17.12 o:43:11 17.23 0:43:41 17.03 o:44:12 17.03 o:44:43 16.79 0:00:35 17.79 0:01 :06 17.71 0:01:37 17.7 0:02:08 17.49 CO2 % 2.21 2.29 2.31 2.44 2.7 2.71 2.74 2.75 2.75 2.79 2.76 2.78 2.78 2.81 2.77 2.84 2.82 2.81 2.81 2.76 2.59 2.51 2.35 2.31 2.34 2.36 2.31 2.35 2.01 1.87 1.99 2.22 2.34 2.41 2.44 2.52 2.62 2.64 2.77 2.76 2.88 2.37 2.33 2.31 2.37 Ve Vr Vo2 Vo2 (Umin) (mUkg/min) (Umin) (L) 14.5 0.48 0.47 7.22 22.68 23.74 27.31 36.37 42.23 43.35 43.7 43.8 44.76 45.59 0.48 0.74 0.91 1.35 1.28 1.44 1 .51 1.46 1.44 1.38 1.39 0.83 0.82 1.1 1.82 2,06 2.03 1,95 1.95 2.05 2.05 2.17 48.76 43.97 1.47 1.93 46.77 1.56 2.13 43.72 1.41 1.94 43.92 1.42 2.07 44.3 1.58 2.08 42.91 1.72 1 .96 29.06 1.21 1.31 21 .82 0.81 0.93 23.02 0.47 0.91 14.35 0.43 0.55 14.03 o.64 o.49 14.29 0.4 0.52 12.6 o.41 o.46 12.99 0.37 0.47 17 .05 0.41 0.62 0.34 9.42 10.76 14,98 19.03 24.86 29.2 36.86 42.4 44.12 45,01 45.43 43.8 42.79 43.12 16.03 13.6 13.31 16.85 0.29 0.37 0.47 o.5 0.99 1.22 1, 12 1.37 1.7 1.73 1.57 1.46 1.58 1.8 0.52 0.5 0.49 0.73 0.32 0.44 0.56 0.93 1.22 1.62 1.83 1 .81 1.86 1 .81 1.84 1.8 1.93 0.54 0.47 0.46 0.63 428 12.72 12.59 16.98 27,93 31.71 31.21 30,01 30.03 31.54 31 .53 33.38 29.64 32.76 29.9 31 .88 32.04 30.11 20.1 14.27 14.02 8.41 7.48 8.D1 7.05 7.22 9.59 5.23 4.99 6.78 8.65 14.35 18.72 24,91 28,09 27.85 28.6 27.88 28,35 27,74 29.7 8.26 7.25 7.14 9.66 HR (bpm) 130 130 135 134 136 130 145 150 152 153 158 APE 13 13 14 Table 62. Subject 173 condition C (cont.). Time 02 CO2 VE Vr Vo2 Vo2 HR RPE h:m:s % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:02:39 17.55 2.33 25.38 0.82 0.93 14.32 0:03:09 18.04 2.33 29.59 0.9 0.9 13.87 0:03:40 17.27 2.64 36.43 1.35 1.44 22.1 0:04:11 16.92 2.65 39.61 1.72 1.74 26.7 0:04:42 16.6 2.67 40.83 1.51 1.95 30 139 0:05:13 16.33 2.75 47.88 2 2.44 37.53 0:05:43 16.6 2.75 51.09 1.89 2.43 37.38 152 13 0:06:14 16.69 2.77 51.01 1.89 2.36 36.35 0:06:44 16.74 2.79 54.51 2.02 2.49 38.34 156 0:07:15 16.87 2.79 53.77 1.92 2.37 36.47 0:07:46 16.65 2.86 52.58 1.95 2.45 37.69 159 15 0:08:17 16.75 2.82 53.37 1.98 2.43 37.31 0:08:48 16.75 2.83 53.47 1.98 2.43 37.43 160 0:09:18 16.67 2.87 55.41 1.91 2.57 39.55 0:09:49 16.75 2.88 52.72 1.76 2.39 36.76 160 16 0:10:20 16.6 2.95 50.36 1.87 2.37 36.46 0:10:50 16.54 2.95 25.05 0.46 1.2 18.43 0:11:21 16.57 2.9 10.47 0.23 0.5 7.65 0:11 :52 16.6 2.89 10.51 0.2 0.5 7.64 0:12:23 16.53 2.94 10.53 0.2 0.5 7.76 429 Table 63. S . ubJect 214 condition C. Time h:m.·s 0:00:36 0:01 :06 0:01 :37 0:02:08 0:02:39 0:03:09 0:03:40 0:04:11 0:04:42 0:05:13 0:05:44 0:06:15 0:06:45 0:07:16 0:07:47 0:08:17 0:08:49 0:09:19 0:09:50 0:10:20 0:10:51 0:11 :22 0:11 :53 0:12:24 0:12:55 0:13:26 0:13:56 0:14:27 0:14:58 0:15:29 0:15:59 0:16:30 0:17:01 0:17:32 0:18:02 0:18:33 0:19:04 0:19:34 0:20:05 0:20:36 0:21:07 0:21:37 o:22:08 0:22:39 0:23:10 0:23:41 % 17.42 17.05 16.38 16.05 16.14 16.05 16.16 16.06 16.21 16.24 16.34 16.32 16.64 16.3 15.91 15.94 15.93 15.85 15.91 15.96 15.91 15.86 15.81 15.94 15.96 15.88 15.9 15.93 16.01 15.9 15.83 15.83 15.76 15.89 15.93 16.19 15.8 15.95 15.92 15.39 15.65 15.69 15.68 15.48 15.53 15.59 VE Vr Vo2 Vo2 % (Umin) (L) (Umin) (mUkg/min) 2.18 20.59 0.82 0.8 10.33 0.85 10.96 14.68 2.53 19.93 0.69 2,69 22.4 0.83 2.72 2.64 2.71 2.68 2.71 2.67 2.69 2.72 2.72 2.63 2.81 2.92 2.9 2.89 2.87 2.88 2.83 2.83 2.87 2.9 2.87 2.86 2.95 2.94 2.93 2.92 2.93 2.97 2.97 2.96 2.92 2.97 2.92 3.01 2.97 3.02 3.28 3.27 3.27 3.3 3.4 3.38 3.33 23.53 0.76 22.79 0.88 23.53 1.02 22.31 0.89 24.45 0.98 24.06 0.86 23.8 0.95 24.31 1.1 26.13 25.14 0.97 26.57 1.21 27.09 1.35 27.27 1.14 28.47 1.24 28.99 0.94 27.63 1.11 28.98 1.26 29.38 1.28 27.31 1.05 29.04 1.21 28.59 1.19 31.73 1.06 30.98 1.29 33.12 1.66 31.67 1.22 32.42 1.41 31.6 1.32 30.6 1.22 30 33.1 32.26 1.2 1.23 1.4 33.28 1.33 31.83 1.22 31.72 1.17 37,88 1.52 36.31 1.51 38.92 1.77 41.24 1.65 42.81 1.95 42.88 1.72 39.75 1.89 40.87 1.57 45.2 2.15 1.13 1.28 1.22 1.28 1.19 1.33 1.27 1.24 1.24 1.34 1.19 1.36 1.51 1.51 1.59 1.64 1.55 1.61 1.65 1.54 1.66 1.59 1.75 1.74 1.85 1,76 1.77 1.77 1.74 1.7 1.91 1.81 1.84 1.67 1.81 2.09 2.01 2.39 2.4 2.47 2.47 2.38 2.43 2.66 430 16.66 15.87 16.66 15.42 17.28 16.43 16.15 16.08 17.35 15.43 17.65 19.63 19.63 20.56 21.34 20.06 20.86 21.37 20.04 21.51 20.63 22.76 22.57 24,01 22,83 22.96 22.91 22.54 22.07 24,76 23.45 23,93 21.61 23.44 27,09 26, 11 31.05 31.1 32.01 32.09 30.92 31.54 34,5 HR (bpm) 89 88 85 86 95 108 97 101 106 105 108 111 115 111 113 118 117 114 135 144 145 150 RPE 7 7 7 9 9 9 10 11 11 12 12 Table 63 Subject 214 condition C (cont.). Time 02 CO2 h:m:s VE Vr Vo2 Vo2 HR RPE 0:24:12 % % (Umin) (L) (Umin) (mUkg/min) 15.74 (bpm) 0:24:43 3.27 45.56 2.17 2.6 33.73 148 0:25:13 15.68 3.29 42.23 1.76 2.44 31.64 0:25:44 15.69 3.25 41 2.05 2.37 30.68 151 0:26:15 15.39 3.32 44.89 1.8 2.76 35.75 13 0:26:46 15.61 3.27 46.93 1.88 2.75 35.72 0:27:17 16.03 3.15 52.35 2.38 2.81 36.45 0:27:47 15.82 3.27 51.92 2.36 2.91 37.78 170 0:28:18 15.72 3.34 57.54 2.4 3.29 42.69 0:28:49 15.78 3.34 55.39 2.22 3.12 40.46 175 15 0:29:20 15.84 3.35 62.19 2.22 3.46 44.83 0:29:50 15.95 3.29 60.38 2.24 3.28 42.53 176 0:30:21 15.91 3.33 61.06 2.18 3.34 43.37 0:30:52 15.82 3.4 60.11 2.4 3.35 43.43 177 16 0:31:23 15.71 3.47 59.43 2.29 3.39 43.91 0:31:54 15.75 3.43 61.16 2.45 3.46 44.82 177 0:32:25 15.7 3.45 62.24 2.31 3.55 46.07 0:32:56 15.73 3.41 61.47 2.12 3.49 45.25 16 0:33:27 15.82 3.33 56.41 1.71 3.15 40.89 17.06 2.59 7.57 0.13 0.32 4.15 431 Table 64 S . · ubJect 221 condition C. Time h:m:s 0:00:35 0:01 :07 0:01 :37 0:02:08 0:02:40 0:03:10 0:03:40 0:04:11 0:04:42 0:05:12 0:05:43 0:06:14 0:06:45 0:07:16 0:07:47 0:08:18 0:08:48 0:09:18 0:09:50 0:10:20 0:10:51 0:11 :21 0:11 :52 0:12:23 0:12:54 0:13:26 0:13:56 0:14:26 0:14:57 0:15:28 0:15:58 0:16:29 0:17:00 0:17:31 0:18:02 0:18:33 0:19:04 0:19:34 0:20:05 0:20:36 0:21 :06 0:21:36 0:22:08 0:22:39 0:23:09 0:23:40 02 % 17.29 17.05 17.18 17.4 18.18 18.5 19 18.84 17.27 17.16 17.05 16.88 16.76 16.63 16.44 16.79 16.57 16.5 16.62 16.46 16.62 16.79 17.1 15.91 15.34 15.3 15.56 15.77 15.91 15.87 15.95 15.9 15.88 15.99 16 15.95 15.59 15.54 15.61 15.52 15.68 15.91 16.17 16.24 16.19 16.23 e r Vo2 Vo2 CO2 V V min) (L) (Umin) (mUkg/min) % (U 2-01 17.6 0.29 0.72 9.59 0.66 8.81 2.11 15.2 0.3 1.98 3.78 0.12 1.82 1.4 1.24 0.99 0.91 1.68 1.74 1.81 1.9 1.9 1.96 2.01 1.88 1.99 1.96 1.94 2.01 1.94 1.91 1.91 2.02 2.18 2.2 2.21 2.19 2.19 2.27 2.22 2.22 2.24 2.26 2.26 2.26 2.35 2.44 2.49 2.56 2.58 2.55 2.55 2.51 2.5 2.5 3.85 0.16 3.84 0.19 3.67 0.09 8.67 0.3 14.7 0.61 15.13 0.41 14.03 0.39 11.75 o.45 11.61 0.37 11.28 0.3 11.38 o.44 14.4 0.6 8.69 0.19 12.16 0.47 10.59 0.44 10.1 0.36 9.72 0.31 13.95 0.38 18.55 0.77 14.81 0.31 17.34 0.35 18.09 o.44 18.67 0.39 19.41 0.59 19.31 o.47 19.65 0.68 18.78 0.59 18.05 0.49 20.9 0.6 19.33 0.47 19.89 0.55 20.73 0.58 25.01 0.76 27.52 0.98 27.36 0.88 28.23 1.23 29.21 1.33 28.35 1.05 32.54 0.9 34.19 0.88 32.88 0.84 32.95 0.97 34.63 1.05 0.16 0.15 0.12 0.1 0.19 0.35 0.63 0.6 0.52 o.54 0.54 0.56 0.74 0.41 0.61 0.54 0.5 0.5 0.69 0.88 0.64 1.01 1.17 1.22 1.21 1,15 1.14 1.09 1.03 1.21 1.12 1.12 1.17 1.43 1.69 1.69 1.72 1.8 1.69 1.85 1.83 1.73 1.76 1.83 432 2.13 2.05 1.6 1.35 2.53 4.72 8.45 8.06 6.95 7.16 7.18 7.47 9.9 5.5 8.09 7.19 6.66 6.64 9.2 11.72 8.59 13.46 15.67 16.3 16.1 15.34 15.14 14.54 13.77 16.11 14.97 14.99 15.59 19.02 22.52 22.56 22.88 24.03 22.57 24,67 24.41 23,13 23.44 24.43 HR (bpm) 124 122 126 123 125 125 139 140 138 138 137 140 APE 10 11 11 12 12 12 · ubJect 221 condition C (cont.). Table 64 S . Time 02 h:m:s % 0:24:12 0:24 :42 0:25:13 0:25:44 0:26:14 0:26:45 0:27:15 0:27:46 0:28:1 7 0:28:48 0:29:19 0:29:50 0:30:21 0:30:52 · 0:31 :22 0:31:53 0:00:36 0:01 :07 0:01:37 0:02:08 0:02:39 0:03:10 0:03:40 0:04:11 0:04:42 0:05:13 0:05:43 0:06:14 0:00:36 0:01 :06 0:01:37 0:02 :08 0:02:39 0:03:09 0:03:40 0:04:11 0:04:42 0:05:12 0:05:43 0:06:13 0:06:44 0:07:15 0:07:46 16.32 16.34 16.29 16.3 16.11 16.26 16.29 16.29 16.3 16.26 16.3 16.29 16.4 16.54 16.31 15.99 15.93 15.82 15.96 15.97 16.06 16.08 16.12 16.12 16.16 16.25 16.12 16.1 17.68 17.09 15.94 15.69 15.54 15.48 15.48 15.92 15.92 16.02 16.16 16.15 16.16 16.23 16.1 % 2.52 2.45 2.51 2.55 2.65 2.64 2.64 2.65 2 .63 2.64 2.61 2.64 2.62 2.6 2.62 2.7 VE Vr (Umin) (L) 34.4 1.11 33.39 1.11 38.51 1.07 38.89 1.39 41.41 1.34 41.13 1.37 39.3 1.16 41.78 1.16 41 .73 1.23 41.78 1.16 42.68 1.04 44.05 1.13 45.36 1.3 40.94 0.97 36.94 1.06 36.27 1.21 3.1 47.91 2 3.32 52.48 1.94 3 .45 56.46 2.17 3.52 58.08 2.23 3.54 60.33 2.41 3.55 62.23 2.07 3.49 65.47 1.98 3.48 63.61 2.19 3.46 64.18 2.14 3.43 63.72 2.06 3.45 64.25 2.29 3.43 65.31 2.11 2.27 22.46 0.45 2.45 28.49 0.75 2.61 32.52 1.35 2.74 37.9 1.35 2.92 44.02 1.69 3.14 55.75 2.32 3.44 65.78 2.35 3.49 67.85 2.42 3.57 69.45 2.24 3.59 73,25 2.36 3.62 76.43 2.07 3.61 74,92 2.2 3.64 76.11 2.06 3.51 81,92 1.82 3.45 63.25 1.07 Vo2 Vo2 (Umin) (mUkg/min) 1.78 23.73 1.72 2.01 2.02 2.24 2.15 2.03 2.16 2.16 2.18 2.21 2.28 2.29 1.99 1.91 2.01 2.64 2.93 3.04 3.11 3.16 3.24 3.38 3.29 3.29 3.2 3.33 3.4 o.79 1.2 1.83 2.24 2.67 3.38 3.94 3.68 3.75 3.86 3.89 3.82 3.86 4.12 3.29 433 22.97 26.75 26.9 29.84 28.6 27.12 28.8 28.77 29.04 29.41 30.41 30.48 26.57 25.4 26.8 35.24 39.1 40.5 41.44 42.08 43.2 45,06 43.83 43.81 42.67 44,34 45,38 10.54 16 24.4 29,89 35,55 45.1 52.49 49,04 50.02 51.46 51.86 50.94 51.53 54,93 43,84 HR (bpm) 140 148 155 152 152 156 158 157 169 170 176 176 181 181 182 188 192 194 199 APE 13 13 13 15 17 18 18 20 Table 65 S . · ubJect 231 condition C. Time h:m:s 0:00:36 0:01:07 0:01 :38 0:02:08 0:02:40 0:03:10 0:03:40 0:04:12 0:04:42 0:05:13 0:05:44 0:06:15 0:06:46 0:07:16 0:07:47 0:08:17 0:08:48 0:09:19 0:09:50 0:10:21 0:10:51 0:11 :22 0:11 :52 0:12:23 0:12:54 0:13:26 0:13:56 0:14:26 0:14:57 0:15:28 0:15:59 0:16:30 0:17:01 0:17:32 0:18:02 0:18:33 0:19:03 0:19:34 0:20:05 0:20:37 0:00:36 0:01:06 0:01:38 0:02:08 0:02:39 02 % 18.85 18.33 18.08 18.04 18.1 18 18 18.09 18.13 18.15 18.05 18.13 18.02 18.07 18.35 17.7 17.6 17.58 17.56 17.61 17.62 17.63 17.63 17.83 17.71 17.85 17.79 17.68 17.49 17.36 17.47 17.29 17.46 17.53 17.49 17.43 17.48 17.59 17.57 17.64 18.46 18.15 18.01 18.13 18.24 CO2 % 1.7 1.88 1.93 1.94 1.9 1.95 1.9 1.87 1.88 1.87 1.88 1.86 1.91 1.86 1.81 2.03 2.06 2.06 2.06 2.07 2.06 2.06 2.08 2.04 2.06 2.04 2.08 2.08 2.18 2.21 2.16 2.24 2.17 2.16 2.19 2.19 2.21 2.17 2.18 2.16 1.72 2.01 2.03 1.97 1.95 VE (Umin) 13.35 14.77 Vr (L) 0.36 0.43 15.91 0.64 15.98 0.43 16.99 0.46 16.23 0.71 16.86 0.73 16.17 0.67 16.46 0.51 15.29 0.53 16.87 0.54 16.39 0.57 15.16 0.32 17.86 0.5 19.52 0.56 20.49 0.53 21.66 0.72 22.37 0.12 22.13 0.85 22.01 o.73 22.04 0.69 22.1 o.79 21.94 0.63 22.18 0.58 22.68 0.91 22.51 0.66 21 .96 0.71 24 0.92 23.97 0.65 24.64 0.88 23.7 0.74 25.93 o.79 26.14 0.84 24,8 0.83 25.01 0.69 24.92 0.83 26.33 0.91 25.48 0.88 25.74 0.86 24.3 0.57 13.33 0.28 12.8 0.44 14,85 0.42 15.78 0.46 20.8 0.56 Vo2 Vo2 (Umin) (mUkg/min) 0.29 4.74 0.41 0.49 0.5 0.52 0.52 0.54 0.5 0.5 0.46 0.53 0.5 0.48 0.56 0.55 0.73 0.8 0.83 0.83 0.81 0.8 0.8 0.8 o.75 0.8 0.76 o.75 0.86 0.91 0.97 0.9 1.04 0.93 0.94 0.96 0.93 o.95 0.87 0.36 0.38 o.47 0.48 0.6 434 6.7 7.99 8.17 8.5 8.41 8.77 8.14 8.16 7.5 8.61 8.11 7.83 9.06 8.84 11.83 12.9 13.43 13.39 13.05 13.04 13.01 12.91 12.17 13.01 12.29 12.21 13.87 14,69 15.73 14,64 16,89 16.2 15.03 15.31 15.55 16.17 15.09 15.33 14.15 5.78 6.21 7.6 7.74 9.77 HR APE (bpm) 88 87 6 93 94 6 101 94 6 98 94 7 100 103 7 100 97 7 107 108 8 109 106 8 104 108 8 Table 65 s . · ubJect 231 condition C (cont.). Time 02 CO2 h:m:s VE Vr Vo2 Vo2 HR RPE 0:03:10 % % (Umin) (L) (Umin) (mUkg/min) (bpm) 0:03:41 17.85 2.12 24.09 0.73 0.81 13.05 0:04:11 17.11 2.24 26.88 0.66 1.14 18.51 0:04:41 16.85 2.27 30.61 0.73 1.4 22.65 127 0:05:13 16.71 2.37 33.6 0.96 1.59 25.71 0:05:44 16.65 2.45 34.44 1.04 1.64 26.66 125 0:06:14 16.81 2.46 33.78 0.94 1.54 24.98 13 0:06:45 16.73 2.6 36.61 1.05 1.7 27.5 128 0:07:17 16.86 2.49 36.36 1.1 1.63 26.48 0:07:47 16.92 2.51 37.01 1.19 1.64 26.51 131 0:08:17 17.12 2.46 37.85 1.18 1.58 25.63 13 0:08:48 17.12 2.47 36.31 1.01 1.51 24.54 134 0:09:19 17.07 2.45 34.25 0.93 1.45 23.51 0:09:49 16.88 2.54 37.02 1.28 1.65 26.78 133 0:10:21 17.1 2.47 36.1 1.09 1.52 24.58 136 13 0:10:51 16.98 2.5 34.9 1.2 1.52 24.59 17.31 2.4 31.56 1.05 1.25 20.19 0:11 :22 17.57 2.31 27.93 0.82 1.02 16.5 0:11 :52 18.12 2.1 19.75 0.62 0.59 9.61 0:12:23 18.12 2.12 17.54 0.84 0.53 8.53 0:12:54 18.32 2.09 14.21 0.39 0.39 6.34 0:13:25 18.35 2.02 13.7 0.42 0.37 6.06 0:13:56 18.27 2.03 16.19 0.33 0.46 7.44 0:14:27 18.31 2.03 22.6 0.63 0.63 10.22 0:14:57 18.28 2.05 25.76 0.83 o.73 11.78 0:15:28 17.54 2.28 31.6 0.93 1.17 18.91 0:15:59 17.19 2.35 34.08 0.95 1.4 22.7 0:16:29 16.99 2.42 38.35 1.24 1.67 27.03 144 0:17:00 16.71 2.52 39.35 1.23 1.84 29.82 0:17:32 16.58 2.63 41.13 1.25 1.98 32.13 148 15 0:18:02 16.76 2.64 41.98 1.2 1.92 31.18 0:18:33 16.84 2.69 41.38 1.33 1.85 29.98 151 0:19:04 16.85 2.69 43.04 1.35 1.92 31.08 0:19:34 16.76 2.77 42.77 1.34 1.95 31.56 156 0:20:05 16.91 2.69 44.08 1.22 1.93 31.3 0:20:36 16.92 2.69 44.79 1.36 1.95 31.67 157 0:21 :07 16.94 2.68 44.2 1.34 1.92 31 .09 0:21 :38 16.9 2.68 43.86 1.22 1.93 31.22 157 15 0:22:08 16.85 2.7 41.5 1.12 1.85 29,92 0:22:40 17.14 2.55 9.07 0.13 0.37 6.06 435 Appendix D Program Listing and Simulation 441 '***** *********• '*****D ******************************************* '*****Developed in Visual BASIC 6.0 '***** Laeveloped by Karen M. Coyne '***** st modified 13MA YOl ******** '***** ********************************************* ,'***** ~~e~ on a Pentium 133 MHz; Windows 95 *********** '***** . *********************************************** '***** ~his program allows the user to examine the effects '***** 0 ~ ~espirator mask on a person during physical '***** act~vity. Default values are provided for all '***** vanables so that the program may be run without '***** ~ny,,user input. The program is run by clicking on '***** the Run Test" button. Default input values may be '******~*anged by clicking on the appropriate button. '*** ************************************************** ** F . '***** . unctions are defined first. The main loop is found '*****,,,.1~}he subroutine cmdRunTest_Click() ************************************************** Public F . 'dete u?ctwn EtaMusc(sgExtW As Single) 'a fun~ne gross muscle efficiency (EtaMusc) as If ction of external work rate (sgExtW) sgExtW < 20.1 Then EtaMusc == sgExtW I 200 Elseif sgExtW < 159.3 Then El EtaMusc == 0.1003 + 0.0006 * (sgExtW -20.1) self sgExtW < 240 Then Els~taMusc == 0.1839 + 0.0002 * (sgExtW -159.3) EtaMusc == 0.2 End If End Function !~~~c Function MetM(sgSurface As Single, sgMass As Single, sgSpeed As Single, sgGrade 'P ingle, sgLdCarried) , and0lf et al. ( 1977) equation for physiological work rate (MetM) irSpeed a?d sgGrade are treadmill spe:d and grade n· m sgWe1ght As Single 'weight of subJect im sgWtCarried As Single 'total weight carried sgWeight == 9.81 * sgMass sgWtCarried == 9.81 * sgLdCarried MetM == 0.15 * sgWeight + 0.2 * (sgWeight + sgWtCarried) * (sgWtCarried I sgWeight)" 2 + O.l02 * sgSurface * (sgWeight + sgWtCarried) * (1.5 * sgSpeed " 2 + 35 * sgSpeed * ~gGrade I 100) - (sgWeight + sgWtCarried) * sgSpeed * sgGmde I lOO nd Function Pubr . · s· 1 ) Jc Function RR(sgMinVol As Single, sgT1dVol As mg e 442 'det · , e:mine respiratory rate (RR) , sg~m Vol is minute ventilation sgTidVoJ is tidal volume E RR = sgMin Vol I sgTidVol nd Function Public F · , unction V02fastss(sgWin As Single) ,!~te:nune the steady-state V02 , is is the ss for the fast component 'sVO~fa~tss = 0.002952 * sgWin 'original equaiton VgWm is physiological work rate (W) 02fastss = 0.0028 * sgWin + 0.4398 End Function P~bli~ Function V02Adj(sgVE As Single) ,adJust V02 based on decrease in VE with respirator tgVE is minute ventilation; V02 - oxygen consumption E 0 2Adj = 0.034 * sgVE + 0.4322 nd Function Publ~c Function SinWR2(Kl As Single, K2 As Single, K3 As Single, c As Single, sgMinVol ~s Single, sgTid As Single, sgT As Single, sgVO As Single, sgVr As Single, inFlag As ~e?er, inMask As Integer, sgEpsilon As Single, sgP As Single) sm 'd , usoi al work rate equations . . ,tom ! oh~son,A T.1993. How much wor~ is ~xpended for respiration? , rontiers m Medical and Biological Engmeermg 5( 4 ):265-287. 's h , ee t e above reference for an explanation of the WR terms K values are Rohrer coefficients, c compliance 's V · , g r is resting lung volume }gEpsilon = 1 for inhalation; = -1 for exhalation mMask=l if mask worn· 0 otherwise 's~P: initial pressure to o~en exhalation valve Dim sgMaxF, sgMaxF2 sgMaxF3 As Single ?im WR1, WR2, WR3.'WR4, WR5, WR6, WR7 As Single ~R ~erms are the work rate components - defined_ in Johnson, 1993 D!m mIE As Integer, sgAA As Single, sgAX As Smg_Je . . ?1m sgVOb As Single, sgVrb As Single, sgTidb As Smgle, sgMmVolb As Single conven units from Land min to ml\3 and sec sgVOb = sgVO I 1000 'initial lung volume sgVrb = sgVr I 1000 'resting lung volume sgTidb = sgTid I 1000 'tidal volume sgMinVolb = (sgMinVol I 1000) I 60 'minute volume If inFlag == 0 Then inIE = 1 'inhalation Else inIE = -1 'exhalation End If pi= 3.1415962 Pi2 =pi* pi 443 sgMaxF- M" s - sg m Volb • sgEpsilon • pi / 2 'max flow axF2 = sgMaxF " 2 sgMaxF3 = sgMaxF " 3 :;~ = sgVOb • pi/ (sgMaxF • sgT) + inlE WR = Sqr(sgAA * sgAA-1) 1 = K 1 * sgMaxF2 / 2 ::~ : 4 * K2 * sgMaxF3 / (3 * pi) WR 4 -:K3 * sgMaxF • pi • ( sgAA - sgAX)) / sgT WR a - ~2 * sgMaxF2 * sgT) / (pi2 * c) WR:b = m!E • sgTidb • (sgVOb- sgVrb) / (sgT • c) W = WR4a + WR4b R5=0 WR6=0 El!R7 = sgP • sgTidb / sgT 'if a mask is worn, work to open valve If inMask = 1 Then WR7=0 End If EndiFnWR2 = WRl + WR2 + WR3 + WR4 + WR5 + WR6 + WR7 s· unction ;u~ic Function HybridExp2WR(Kl As Single, K2 As Single, K3 As Single, c As Single, l ;"Vol As Single, sgVr As Single, inFlag As Integer, sgEpsilon As Single, sgVO As 1~; e, .sgT1d As Single, sgT As Single, sgP As Single, inMask As Integer) 'f ybnd exponential work rate equations , rom Johnson (1993) ,K values are Rohrer coefficients c compliance sgV · ' , r is resting lung volume .~gEpsilon = 1 for inhalation;= -1 for exhalation ,mMask=l if mask worn· 0 otherwise sgP· · · · ' D' · m,ual pressure to open exhalation valve 0 '.m WRl , WR2, WR3, WR4, WR5, WR6, WR7 As Single . 0 1 m sgTau As Single, sgTR As Single, sgMT As Smgle, sgMfau As Smgle 0 '.m sgMaxF As Single, sgMaxF2 As Single, sgMaxF3 As. Smgle 0 '.m sgExp8 As Single, sgExpi6 As Single, sgExp24 As Smgle o:m sr As Single, cc As Single, L6 As Single, bb As S1~gle Dim ss As Smgle, aa As Single, ep As Single, em As Smgle 0 .m b As Smgle, XI As Single, X2 As Single . im rl As Single, r2 As Single, r As Single, L5 As Smgk . . g,m sgMinVolb As Single, sgVOb As Single, sgVrb As Smgle, sgTtdb As Single , im mIE As Integer convert units from L and min to m"3 and sec sgMinVolb = (sgMinVol / 1000) / 60 'minute volume sgVOb = sgVO / 1000 'initial lung volume sgVrb = sgVr / 1000 'resting volume sg!idb = sgTid I 1000 'tidal volume If mFlag = 0 Then inIE = 1 'inhalation Else inIE = -1 'exhalation End If sgTau = (K 1 + K2 * sgMin Volb * sgEpsilon + K3 / (sgVOb + inIE * sgTidb / 2)) * c sgTR = sgT I sgTau sgExp8 = Exp(-0.8 * sgTR) sgExpl6 = sgExp8 "2 ~gExp24 = sgExp8 * sgExpl6 sgMaxF = sgMin Volb • sgEpsilon / (0.05 + ( I - sgExp8) / sg TR + 0.05 • sgExp8) sgMaxF = sgTidb / (sgTau * (1 - sgExp8) + 0.05 * sgT * (1 + sgExp8)) sgMaxF2 = sgMaxF " 2 sgMaxF3 = sgMaxF " 3 sgMT = sgMaxF * sgT sgMTau = sgMaxF * sgTau WRI = KI • sgMaxF2 • (( 1 + 8gExpi6) / 15 + (I - sgExp 16) I sgTR) 12 WR2 = K2 • sgMaxF3 • (( J + ,gExp24) / 40 + ( I - sgExp24) I (3 • sgTR)) b = sgVOb / sgMT ss = Sqr(20 * b) aa = 2 - 2 * ss * Atn(l / ss) ep = ( 1 + sgExp8) em = 1 - sgExp8 X l = b + inIE * 0.05 X2 = Xl + inIE * em/ sgTR If X 1 I X2 < 0 Then 'nothing Else LS= Log(Xl I X2) End If bb = -inIE * em - LS * sgTR * (Xl + inIE / sgTR) a= ~2 - inIE * 4.95 * sgExp8 rl = mIE * 20 *a* sgExp8 + 100 * sgExpl 6 r2 = 2 * sgExp8 r = -rl If r > 0 Then sr = Sqr(r) cc= (-2 * inIE * rl / sr) * Atn(sgExp8 I sr) - inIE * rZ Else sr = Sqr(-r) L6 = inIE * Log((sr + sgExp8) / ((sr - sgExpS))) cc = (r 1 * L6 / sr) - inIE * r2 End If ~R3 = K3 * sgMaxF * (aa + bb + cc) I sgT WR4a = sgMaxF2 / (sgT * c) WR4bl = (sgT" 2) / 800 :WR4b2 = sgTau • (0.05 • sgT + sgTau) * (I - sgExP 8 l WR4b3 = ((sgTau • 2) / 2) • (I - sgExpl6) 5 • 5 Exp8) + 0.05 • sgTau * sgT • (I - WR4b4 = sgExp8 * ((sgT" 2) * (0.0025 + o.OOl 2 g sgExp8)) 'WR4b = WR4bl + WR4b2 + WR4b3 + WR 4 b4 :WR4c = in!E • sgTidb • (sgVOb - sgVrb) / (sgT • c) WR4 = WR4a * WR4b + WR4c 445 'WR4 below t k WR4 _ . a en from respwork program summer 2000 WRs; ~gTidb * (sgTidb I 2 + inlE * (sgVOb - sgVrb)) I (sgT * c) WR6:::::o If in.Mask ::::: 1 Then Els:R7 ::::: sgP * sgTidb I sgT 'if a mask is worn, work to open valve WR7:::::o End If I-lyb . TJ 0 Then sr = Sqr(r) cc = (-2 * inIE * rl / sr) * Atn(sgExp8 / sr) - inIE * r2 Else sr = Sqr(-r) L6 = inIE * Log((sr + sgExp8) / ((sr - sgExp8))) cc= (rl * L6 / sr) - inIE * r2 End If 'X = sgVOb / sgMT + inIE * 0.05 'L5 = Log(X / (X + inIE * ( 1 - sgExp8) I sgTR)) 'bb = -inIE * ( 1 - sgExp8) - L5 * sgTR * (X + inIE / sgTR) sgVOb = sgRVb - inIE * (0.05 * sgMT * sgMTau) WR3 = K3 * sgMaxF * (aa +cc)/ sgT 'aa = sgMaxF * (sgFRCb - sgVOb + sgMaxF * sgT / 40) / (c * 20) 'bb = sgMaxF * sgExp8 * (sgFRCb - sgVOb + sgMaxF * (sgT / 20 + sgTau * (1 - sgExp8)) + sgMaxF * sgExp8 * sgT / 40) / (c * 20) 'WR4 = aa + bb 'WR4 = sgMaxF * sgT * (sgMaxF * ( 1 / 40 + sgExp8 / 20 + sgExp 16 / 40 + sgExp8 * em/ sgTR) - sgTidb * (sgVOb - sgFRCb) * (1 + sgExp8) / sgT) / (20 * c) WR4 = (sgMaxF2 * sgT / (20 * c)) * (1 / 40 + sgExp8 / 20 + sgExpl6 / 40 + (sgTau * sgExp8 / sgT) * (1 - sgExp8)) - (sgVOb - sgFRCb) * (0.05 * sgT * sgVmax) * (1 + sgExp8) / (c * sgT) kmc=c WR5 = sgl * sgMaxF2 * (1 - sgExpl6) / (2 * sgT) sgExpl = Exp(-0.1 * sgTR) sgExp9 = sgExp l * sgExp8 cl= 0.145 c2 = 0.306 c3 = 100 * (0.1 * sgMT + 2 * sgMTau + sgRVb) / sgVCb c4 = -100 * sgMTau / (sgExpl * sgVCb) c5 = c 1 * sgMaxF / sgExp 1 447 c6 = c2 * a = c3 sgMaxF / sgExp 1 b _ + c4 * sgExp9 WR.~3_+ c4 * sgExpl sgTau •; ~MaxF * sgTau I sgT) • (4325.651 '(1 - sgExp8) + (11703.94 / (2 • sgVCb)), 'WR g . axF * (1 - sgExp16)) If inM 6 kts pmax*flow during the flow-limited portion of the wavefonn as = 1 Then El:R 7 = O. 05 • sgP • sgMaxF • sg T • ( 1 + Exp8) 'if a mask is worn, work to open valve WR7=0 End If FlowLirn2WR = WRl + WR2 + WR3 + WR4+ WR5 + WR6 End Function Public Fu . , h ~ction Te(sgRPD As Single) {; _alat,on time (Te )as a function of respiratory period(sgRPD) En -0.6 l76 * sgRPD-0.2145 p d Function ublic Fun . . ,. h ction T1(sgRPD As Single) ;~ __'.'lation time (Ti)as a function of respiratory period (sgRPD) End F- sg~PD - (0.6176 * sgRPD - 0.2145) unction Public Fu · · K3 A s· l A s· 1 Sin 1 nct,on Trap3WR(Kl As Single, K2 As Smgle, s mg e,.c s mg e, sgVr As inFfa e, sgP As Single, inMask As Integer, sgTidal As Single, sgT As Smgle, sgVO As Single, 't g As Integer, sgMinVol As Single, sgEps,lon As Smgle) rapezoidal 'f work rate equations .~om Johnson ( 1993) , Vvalues are Rohrer coefficients c compliance sg . ' 's r 1.s resting lung volume ,. gEpsilon = 1 for inhalation· - -1 for exhalation ,inMpask=l if mask worn· O dtherwise sg . . . . , D' · miual pressure to open exhalation valve D~m sgVmax As Single D:m WR!, WR2, WR3, WR4, WR7 As Single . Dim s As Single, L2 As Single, q As Single, J2a As S~ngle Dim q 1 As Single, p 1 As Single, p As Single: L3 As Smgle Di: sgVOb As Single, sgVrb As Single, sgTtdalb As single , mlE As Integer, sgMin Volb As Single ,convert units from Land min to m•3 and sec /MmVolb = (sgMinVol / 10()()) / 60 'minute volume s g~Ob = sgVO I 1000 'initial lung volume s g _rb = sgVr / 1000 'resting volume 1 f !1dalb = sgTidal / 1000 'tidal volume ~nFlag = 0 Then mlE= 1 Else inlE=-1 448 End If pi= 3.14 sgVmax- T' sgVmax;: ssg •.dalb / (0.825 * sgT) WRl = 0 gMmVolb * sgEpsilon/0.825 WR2 = 0·;30556 * Kl * sgVmax" 2 b = sgVOb 729416 * K2 * sgVrnax" 3 ss = S ( (sgVmax * sgT) qr 20 * b) aa = 2 - 2 * * ql = inIE * ss Atn(l / ss) q2 = 0.3333~~166667 * b + 1.020833 q3 = 0.8333333 q = -ql If q > o Then sq= Sqr(q) bb = (2 * 1 Else q / sq) * ( Atn( 1.010417 I sq) - Atn(O. 9270833 / sq)) - in!E • q2 sq= Sqr(-q) L2a-Ab ( L2 =-: s (sq + I) * (sq - q3) / ((sq - I) ' (sq+ q3))) mIE * Log(L2 ) bb=ql * a End If L2 / sq - inIE * q2 pl= inIE * 2 - l 16,66667 * b + 13.75 - .666667 p = -pl If p > 0 Then sp = Sqr(p) cc= (-inIE * 2 Else 'pl/ sp) * Atn(q3 / sp) • inIE 'p2 sp = Sqr(-p) L3 = inIE * L cc = 1 , og(Abs((sp + q3) / (sp - q3))) End If p L3 I sp - inIE * p2 WR3 =K3 * If inFl sgVmax ' (aa + bb +cc)/ sgT W ag=OThen Else R 4 = 0.3403343 • (sgVmax, 2 • sgT / c) + sgTidalb * (sgVOb • sgVrb) I (sgT • c) En':: 4 = 0.3403343 '(sgVmaX' 2 • sgT / c) - sgTidalb * (sgVOb- sgVrb) / (sgT' c) If' mMask = 1 Th WR7- en Else - sgP * sgTidalb / sgT 'if a mask is worn, work to open valve WR7=0 End If Trap3WR End Fu . =WR!+ WR2 + WR3 + WR4+ WR7 Pub . nct10n sgJ'~ Function VOi(sgVit As Single, sgRes As Single, sgTid N Single, sgFRC As Single, 'd s Smgle) etermi ne the starting volume for inhalation 449 Dim a Ass· 1 i mg e, b As Single, c As Single Di: ~iesb As Single, sgVitb As Single, sgFRCb As Single, sgTidb As Single , itemp As Single convert from L to m"3 ::~~t:-: sgR_es I 1000 'residual volume sg~C -~gVit I 1000 'vital capacity sgr· db b_ - sgFRC / 1000 'functional residual capacity a = ~- 39 - sgTid I 1000 'tidal volume ~ :-a/ (sgTidb + 2 * sgResb) + 2 * sgVitb VO. a sgResb • ( sgResb + sg Tidb) - sgVitb • ( sg Tidb + 2 * sgResb + sg Vitb) lf{te.mp = (-b + (b • b-4 •a• c)' 0.5)/(2 • a) V O~temp < sgResb Then 01temp = sgResb End If 'f ,, or 1?w work rates VOi is FRC ior hght ·1 · · d FRC If 1 18 midway between calculated volume an sgW < 5 Then VO" Else 1 = sgFRC '* 1000 'convert back to L If sgW < 35 Then VOi = (((sgW - 5) • VOitemp + (35 • sgWl • sgFRC) / 30) • 1000 'convert back to L Else VOi = VOitemp * 1000 End If End If End Function Public F . 'det u~ctmn AT(sgMax As Single) , ~rmme anaerobic threshold (AT) :\ _ax:maximum oxygen consumption (mLfkglmin) End -0.&624 • sgMax - 7.!585 •mVkg/mtn u~lic Function Vminss(sgPerc As Single, sgMax As Single) p Function ,determine steady-state minute ventilation (VminSS) sgPe · , re is percent of vo2max s~Max is vo2max (Umin) g~m sgVEmax As Single 'minute ventilation im sgVEPercMax As Single '% of max VE sgVEmax = 20.01 * sgMax + 27.855 'Umin , ~V_EPercMax = 0 _ 0095 • (sgPerc • sgPerc)-0.133 • sgPerc + 17.153 % eg 80% E nunss = sgVEPercMax • sgVEmax/ JOO ,urmn nd Function Pu~!ic Function VERes(sgPerc N, Single, sglnh As Single, sgExh As Single) ,determine change in VE due to added resistance (vERes) ,sgPerc: % ofvo2max . ,sglnh and sgExh are inhalation and eXbalation re 51 S!llnces sglnh and sgExh (cmH20/IJS) If sgPerc < 30 Then 'below 30% vozmax 450 -VERes = -0.0037 * sginh - 0.0223 * sgExh Else If sgPerc < 40 Then 'between 30 and 40%V02max VERes = -0.0018 * sginh - 0.0206 * sgExh Else If sgPerc < 50 Then 'between 40 and 50% V02max VERes = -0.0065 * sginh - 0.0469 * sgExh Else If sgPerc < 80 Then 'between 50 and 80% V02max VERes = -0.0156 * sglnh - 0.0846 * sgExh Else 'above 80% V02max VERes = -0.0454 * sglnh - 0.0967 * sgExh End If End If End If End If End Function Public Function VEVD(sgPerc As Single, sgVD As Single) 'determine change in VE due to added dead space (VEVD) 'sgPerc - % V02max 'sgVD - dead volume Dim VEchange As Single, sgFract As Single 'VEchange - change in VE due to VD (temporary variable) sgFract = sgPerc I 100 '% V02max expressed as decimal VEchange = 0.170432 * sgVD - 0.00681 - ((sgFract - 0.15) I 0.15) * ( 1.8 / 60) If VEchange < 0 Then 'no decreases in VE due to VD VEVD=O Else VEVD = VEchange End If End Function Public Function VTidss(sgPerc As Single, sgMax As Single) 'determine steady-state tidal volume (VTidss) 'sgPerc - %V02max 'sgMax - V02max (Umin) Dim sgVTmax As Single 'maximum tidal volume Dim sgVTPercMax As Single'% of max tidal volume sgVTPercMax = 0.9987 * sgPerc - 1.6809 sgVTmax = 0.3864 * sgMax + 0.6416 'L VTidss = sgVTPercMax * sgVTmax / 100 'L End Function Public Function VTRes(sgPerc As Single, sglnh As Single, sgExh As Single) 'determine change in tidal volume with added resistance (VTRes) If sgPerc < 30 Then 'less than 30% V02max VTRes = 0 Else If sgPerc < 40 Then 'between 30 and 40% V02max 451 El~TRes = 0.0092 * sglnh + 0.208 * sgExh If sgPerc < 50 Then 'between 40 and 50% V02max VTRes = O Else If sgPerc < 80 Then 'between 50 and 80% V02max VTRes = O Else 'greater than 80% V02max VTRes = -0.0162 * sglnh + 0.0746 * sgExh End If End If End If End If End Function Public F · A s· l ) 'de unchon VTVD(sgPerc As Single, sgVD s mg e , termme the change in tidal volume with added dead space (VTVD) sgPerc - % V02max ~7VD -dead volume (L) . . D" m VTchange As Single \emporar)' variable change 1n VT with VD im sgFract As Single '% V02max in decimal form sgFract = sgPerc / 100 If sgPerc < 15 Then 'below 15%V02maX El~Tchange; 0.7468 • sgVD-0.08445 If sgPerc < 30 Then 'between 15 and 30% vo2max VTchange = 0.9933 * sgVD -0.2537 VT change ; O. 195 + 0.2517 • sg VD - o.4256 • sgFract Else 'over 30% V02max End If End If If VTchange < 0 Then El~TVD ; 0 'no decreased in VT due to VD E VTVD = VTchange nd If End Fun t ' Pu . c 10n . ~1c Function 02Def(sgAdi As Single, sgSS As Smgle) ,,'°d ~xygen deficit (Umin) of mask , gAdJ - vo2 adjusted for resistance and dead volume ~~SS - vo2 required by the activity E Def= sgSS - sgAdj nd Function Privat s 'b e ub cmdMainExit_ClickO utton on form main 'click on this button to terminate the program 452 I , End End Sub Public Sub cmdRunTest_Click() 'button on form main 'click on this button to run the program Dim I As Integer 'counter 'declare metabolic variables Dim sgMetM As Single 'physiological work rate, W 'declare general variables Dim sgSubjMass As Single 'subject mass, kg Dim sgSubjHt As Single 'subject ht, cm Dim inSubjAge As Integer 'subject age.yr Dim sgBMI 'body mass index Dim sgGender As Single Dim inFitness As Integer 'fitness level 'declare thermal variables Dim sgRestCoreTemp As Single 'resting core temp,C Dim sgTerrain As Single 'terrain coefficient Dim stTerrain As String 'terrain name 'dee !are respiratory variables Dim sgKlaw As Single 'Rohrer coefficients Dim sgK2aw As Single 'aw is airways Dim sgK3aw As Single Dim sgKllaw As Single 'inhalation Kl airways coefficient Dim sgK2Iaw As Single 'inhalation K2 airways coefficient Dim sgK3Iaw As Single 'inhalation K3 airways coefficient Dim sgKlEaw As Single 'exhalation Kl airways coefficient Dim sgK2Eaw As Single 'exhalation K2 airways coefficient Dim sgK3Eaw As Single 'exhalation K3 airways coefficient Dim sgKll As Single 'total inhalation Kl coefficient Dim sgK21 As Single 'total inhalation K2 coefficient Dim sgK31 As Single 'total inhalation K3 coefficient Dim sgKlE As Single 'total exhalation Kl coefficient Dim sgK2E As Single 'total exhalation K2 coefficient Dim sgK3E As Single 'total exhalation K3 coefficient Dim sgCompliance As Single 'compliance value for Rohrer equation Dim sglnertia As Single 'inertia value for Rohrer equation Dim sgRestV02 As Single 'resting V02 Dim sgV02max As Single 'max oxygen consumption Dim sgRelV02max As Single 'V02max in ml/kg/min Dim sgAbsV02max As Single 'V02max in Umin 'Dim inV02maxTime As Long 'time variable for later Dim sgV02Percent As Single '%V02max Dim sgV02Fract As Single '%V02max in decimal form Dim sgVitCap As Single 'lung vital capacity, L Dim sgResVol As Single 'lung residual volume, L Dim sgVrest As Single 'resting volume set= FRC Dim sgFuncResCap As Single 'functional residual capacity 453 g~m sgVOe As Single 'initial volume for exhalation D~m sgVOi As Single 'initial volume for inhalation D;m sgVERadj As Single 'VE adjustment for resistance D" m sg VTRad J As Smgle ·vr adjustment for reS1stance D,m sgVEVDadj As Single 'VE adjustment for dead space D;m sgVTVDadj As Single 'VT adjustment !or dead space D' m sgVEadJ As Smgle 'VE adjusted for reS1stance and dead volume D,m sgVTadj As Single 'VT adjusted for resistance and dead volume ~m sgV02adj As Single 'V02 adjusted for resistance and dead volume g~m sgVTss As Single 'steady-state VT, L Dim sgVEss As Single 'steady-state VE. Umin Dim sgV02ss As Single 'steady-state VOZ. Umin . . •m sgRelAnThresh As Single 'anaerobic threshold m mJ/kg/mm D~m sgAbsAnThresh As Single 'anaerobic threshold in J.}min g~m sgRespRate As Single 'respiratory rate D~m sgTexp As Single 'exhalation time, sec ~m sgTinsp As Single 'inhalation time, sec D~m sgRespAddRinh As Single 'added lung resistance D~m sgRespAddRexh As Single 'added lung resistance D~m sgRespAddVD As Single 'added lung dead v~lume . Dim sgEpsilonE As Single 'dimensionless conversion between Texp and Tmsp Dim sgEpsilonl As Single 'conversion between Texp and Tmsp D~m sgRespPeriod As Single 'respiratory period, sec Dim sgRespWRexh As Single 'exh work rate for resp,W g,m sgRespWRinh As Single 'inh work rate for resp,W D~m sgRespWR As Single 'total resp work rate,W ~m sgRespWexh As Single 'exh work, Nm g,m sgRespWinh As Single 'inh work, N ID D,m sgRespW As Single 'total resp work, Nm ~m sgPmax As Single 'max lung pressure . ~,m sgRespMuscEff As Single 'resp muscle efficiency ~clare test parameters D~m sgEnvirTemp As Single 'ambient temp, C D~m sgRelHum As Single 'relative humidity, % Dim sgExt W orkRate As Single 'external work rate, W Dim sgTreadSpeed As Single 'treadmill ,peed, irJs Dim sgTreadGrade As Single 'treadmill grade,% Dim sgLoad As Single 'load carried, kg n· kmass •m sgTotalMass As Single 'load+ subjmaSS + mas Dim sgTotaILoad As Single 'load+ mask"':'"' kg w g•m sgPhys WorkRate As Single ·~hysiological work rate, 'dim sgStepRate As Single 'step/mm ~clare respirator parameters D~m inRespirator As Integer 'resp worn if::> O D~m sgEccentricity As Single 'for later use k mJ-lZO!Us Dim sgMaskRinh As Single 'inh resistance of mas ' ccm!l20JL/s Dim sgMaskRexh As Single 'exh resistance of mask, Dim sgMask VD As Single 'dead volume of mask, L Dim sgMaskMass As Single 'mass of mask, kg 454 Dim sgM ' askP As Sin l ' , I sgDeltaVD g e pressure to open exh valve declare oth As Smgle 'change in dead volume Dim s G ~r variables Dim sgg ~av1ty As Single '9.81 rn/s"2 1m myfile mg e gross muscular efficiency D' uscEff Ass· l I Dim mydat n~me As String 'file name for data Dim m . e s Stong 'date D . yt1me As St · , . 1m std nng ume im std~mmy 1 As String 'used for printing to myfile Dim in W mmy2 As String 'used for printing to myfile Dim sgPe~lag As Integer 'flag for which work rate equation to use '* Dim sgMax ,me As Smgle 'performance time, min ********* Deficit As Single 'max 02 deficit 1nW ••••••••••••••••••••••••••• . ******** orkFlag _ 0 ,. . . . mydat _ - 1mt1ahze e- Date mytime -T· - 1me sgMaxDefic' sgGravity = ~ = 4,03 'L, taken from Bearden and Moffatt (2000) sgM .81 , ••• • • u .-;. •. · pressure to open the exhalation valve;from M 17 mask Write t "'* ********************************** '** askP - 59 93 ' '* s art co d' . ****** n it1ons to file ****** myfil ••••••••••••••••••••••••••••••••''' Open ena~e = "c:IPhDIProgram\OutPut Files\" & fr!DMain.txtstartfile.Text Open my I lename & "init" For Output Access Write As # I Print ;;y~lename & "resp!" For Output Access Write As #3 Pr· ' start Conditions File" mt#l "T. Pr· ' nal conducted· "· mydate mytime II mt #1 • ' ' **** ' p. •••••••••••••••••••••••••••••••••••••••••••••••••••••••••• ******* nnt #3 "R . P · ' esp1ratory Data # 1" nnt #3 "T. l .. Pri , na conducted:"; mydate, mytime **** ' •••• ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• get •••••••••••••••••••••••••••••••••••••••*'''''''''''' I ****** I ****** , values~ . . ""***'* or vanables from the fonns and wnte to file • ••••••••••••••••••••••••••••••••••••••••••••••••••••••• ese variabl sgSub'M es are on the form SetGenrarams sgsu:- ass = f rmSetGenParams, txtSubjMass,TeXt sgBJi~t = frmSetGenParams,txtSubj!lt,Text I 100 sgSub' A, sgSubJMass / (sgSubj!lt' 2) If f rmi ge = frmSetGenParams,txtSubjAge· rext sgG etGenParams.optFemaJe.Value::: rrue Then s ender = 0.85 tdummyl "F Else = emale" sgGender = 1 E stdummyl = "Male" nd If 455 If fnnSetGenParams.optUntrained.Value = True Then inFitness = O stdummy2 = "Untrained" Else If fnnSetGenPararns.optTrained.Value = True Then inFitness = 1 stdummy2 = "Trained" Else inFitness = 2 stdummy2 = "Highly Untrained" End If End If 'write general parameters to file Print # 1, "Subject Characteristics" Print #1, "-------------" Print #1, "Mass (kg)", sgSubjMass Print #1, "Height (m)", sgSubjHt Print #1, "Age (yr)", sgSubjAge Print # 1, "Gender" , stdumrnY 1 Print #1, "Fitness" stdununy2 *****"'***''""*** '***************~***************** 'get thennal values *************** '******************************** C Temp.Text nnP ms txtRest ore ~gRestCoreTemp = frrnSetTh~ ara If. hysiological get terrain coefficient for use m Pando P 'work rate equation _ True Then If frmSetTherrnPararns .optTI.Value - sgTerrain = 1 # _ True Then Elself frmSetThermParams.optTZ.Value - sgTerrain = 1.1 e _ True Then Elself frmSetThermParams.optT3.v:i,;ams,txtDepth.Text sgTerrain = 1.1 + 0.1 * frmSetThe lue _ True Then Elself frmSetThermParams.optT4.Va - sgTerrain = 1.2 1 _ True Then Elself frmSetThermParams.optT5.Va ue - sgTerrain = 1.5 e _ True Then Elself frmSetThermParams.optT6.Valu - sgTerrain = I.8 _ True Then El self frmSetThermParams.optT7 · Value - sgTerrain = 2. 1 End If 'write thermal parameters to file ***************" ******* Print #1 , *************** "******************************* Print #1, "Thermal Inputs" P " rint #1 "-------------- Print #1: "Core Temp",, sgReSlCo~TemP *** Print #1 "Terrain Factor", sgTerram*************** '******;********************** 456 '***** , get resp· r t ******** 1 a ory system values ********* If frmS ****************************** etRespP sgAbsV0 2 arams.optMaxL.Value = True Then sgRe!V0 2 max= frmSetRespParams.txtV02Max.Text Else max= sgAbsV02max' !000/ sgSubjMass sgAbs V0 2 max = fnnSetRespParams.txtV02Max.Text sgReI 02 End If max= sgRe!V02max • sgSubjMass / !000 sgRes v ~ :: frmSetRespParams.txt VC. Text VitCa - sgFuncR - fnnSetRespParams.txtR V. Text sgResp:sCap = f nnSetRespParams.txtFR C. Text sgRespAI:°Eff = fnnSetRespParams-txtRespMuscEff. Text sgRespAdd Rmh = fnnSetRespParaJDS·txtAddlnspR Text sgRespAd/exh = frmSetRespParams.txtAddExpR.Text 'writer . VD= fnnSetRespParams.txtAddVD.Text Print espiratory parameters to file Pn· ''*""'"'''''*"'"'*''""'""''*'**'''*"'*'*'**'*'*" "** #1, ********* nt #1 "R . P · ' espiratory Inputs" nnt #1 " p . . ---------- " nnt # 1 "V ------Print #I ' " 0 2 max (Umin)",. sgAbs V02maK Print # 1 ' ,, V 0 2max ( mUkglmin)", , sgRelV02JD3X P · ' Vital Capacity (L)" sgVitCap nnt #1 "R . '' rint #I•" eSidual Volume (L)",, sgResVol Print # 1 ' "Functtonal Residual Capacity (L)", sgFuncResCaP Print# ',,Resp. Muse. Eff. (%)",, sgRespMuscEff Print # 1 • "Additional Resp. Res. Jnh. ( cm!l20/l}S)", sgRespAddRinh Print# 1 • ,,Additional Resp. Res. Exhh- (cm!l20/l}S)", sgRespAddRexh ,,.,,};, Additional Resp. Dead Vol. (L)", sgRespAJdVD ' ········································ get resp· . '*** irator information ****** ' ······································ eccent .. sgE ncity - respirator mass not evenlY distributed on bead ccentr' · · · T t If f ICIiy = fnnSelectRespirator.txtEccentnc1tY- ex s rmSelectRespirator.optM J 7. Value = True Then 'MI 7 selected . tdummy 1 = "M 17" irator = 1 'respirator worn mResp· sgMaskRinh = 3.4 sgMaskRexh = 1 3 sgMaskVD = 350 / 1000 'L El:!MaskMass = 1 * sgEccentricitY If (nnSelectRespirator.optM40.Value = True Then M40 selected ~tdummyl = "M40" mRespirator = 1 'respirator worn sgMaskRinh = 3.17 sgMaskRexh = 1.69 457 sgMaskVD = 300 / 1000 'L sgMaskMass = 0.7 * sgEccentricity Else If frrnSelectRespirator.optOther.Value = True Then 'other respirator selected 'user sets resistance, dead volume, and mass stdummy 1 = "Other" inRespirator = l 'respirator worn sgMaskRinh = frrnSelectRespirator.txtRinh.Text sgMaskRexh = frrnSelectRespirator.txtRexh.Text sgMaskVD = frrnSelectRespirator.txtRVD.Text / 1000 'L sgMaskMass = frmSelectRespirator.txtRMass.Text * sgEccentricity Else If frrnSelectRespirator.optNone.Value = True Then stdummy 1 = "None" inRespirator = 0 'respirator not worn sgMaskRinh = 0 sgMaskRexh = 0 sgMaskVD =0 sgMaskMass = 0 End If End If End If End If 'print respirator information to file Print #1, "********************************************************************" Print # 1, "Respirator Selected" Print # l, "-------------------" Print # 1, stdummy l If inRespirator = 1 Then Print #1, "Mask Inh. Res. (cmH20/IJs)", sgMaskRinh Print #1, "Mask Exh. Res. (cmH20/IJs)", sgMaskRexh Print #1, "Mask Dead Vol. (L)", sgMaskVD Print #1, "Mask Mass (kg)", sgMaskMass End If '*********************************************** 'get test values '*********************************************** sgEnvirTemp = frmSetTestParams.txtEnvirTemp.Text sgLoad = frmSetTestParams.txtLoad.Text sgRelHum = frmSetTestParams.txtRe!Hum.Text 'write test parameters to file Print #1, "********************************************************************" Print #1, "Test Inputs" Print # 1, "-----------" Print #1, "Environ. Temp.(C)", sgEnvirTemp Print #1, "Rel. Humidity(%)", sgRe!Hum 458 ----------- Print #1 "L 'd . ' oad Carried (kg)", sgLoad erellnine eq · If fnns uation to use for external work rate calculation sgE etTestParams.optExtWR. Value= True Then inW xtWkForkRate = fnnSetTestParams.txtExtWR.Text or Iag = 1 Print #1 "E If. R '. xternal Work Rate (W)", sgExtWorkRate 10 espirator = 1 Then ;;;xtWo,:kRate = sgE~tWorkRate * (1 + (sgMaskMass + sgLoad) I sgSubjMass) End I;t #l, Ext. WR Adjusted for Total Load (W)", sgExtWorkRate Else If frrnSetTestParams.optTreadmill = True Then sgTreadSpeed = frmSetTestParams.txtSpeed. Text sgTreadGrade = fnnSetTestParams.txtGrade. Text sgT dsgExtWorkRate = (sgSubjMass + sgLoad + sgMaskMass) * sgGravity * rea Speed * sgTreadGrade / 100 Pr!nt #1, "Treadmill Speed (mis)", sgTreadSpeed Pr!nt #1, "Treadmill Grade(%)", sgTreadGrade ~nnt #1, "Ext. WR Adjusted for Total Load (W)", sgExtWorkRate In WorkFiag = 2 Else If frrnSetTestParams.optBike = True Then sgCadence = fnnSetTestParams.txtCadence sgBikeLoad = fnnSetTestParams.txtBikeLoad sgBikeDistance = frmSetTestParams.txtBikeDistance sgExtWorkRate = sgCadence * sgBikeLoad * sgBikeDistance * sgGravity I 60 Print #1, "External Work Rate (W)", sgExtWorkRate Print #1, "Cadence", sgCadence Print #1, "Bike Load (kg)", sgBikeLoad Print #1, "Bike Distance per rev. (m)", sgBikeDistance Else If fnnSetTestParams.optStep = True Then sgStepHt = fnnSetTestParams.txtStepHt sgStepRate = frmSetTestParams.txtStepNum I 60 sgExtWorkRate = sgStepHt * (sgSubjMass + sgLoad + sgMaskMass) * sgStepR * . ate sgGravity ,, Print #1 , "Ext. WR Adjusted for Total Load (W) , sgExtWorkRate Print #1, "Step Height (m)", sgStepHt Print #1 , "Step Rate (steps/min)", sgStepRate End If End If End If End If '** Close #1 'close file with initial parameter values ********************************************* sgM.uscEff = EtaMusc(sgExtWorkRate) 'gross muscle efficiency sgTotalMass = sgSubjMass + sgLoad + sgMaskMass :total mass ,sgTotalLoad = sgLoad + sgMaskMass 'total mass earned If (sgTreadGrade = O) And in WorkFlag = 2 Then 459 If in W orkFlag = 2 Then 'treadmill work selected sgPhysWorkRate = MetM(sgTerrain, sgSubjMass, sgTreadSpeed, sgTreadGrade, sgTotalLoad) frmMain.txtPandolf.Text = "Pandolf used" Else If sgExtWorkRate = 0 Then sgPhysWorkRate = 105 'basal metabolic rate, W Else sgPhys WorkRate = sgExtW orkRate / sgMuscEff End If End If If sgPhysWorkRate < 105 Then sgPhysWorkRate = 105 End If If (inRespirator > 0) And (inWorkFlag = 2) Then 'respirator is worn; treadmill work selected sgPhysWorkRate = sgPhysWorkRate * (1 + (sgMaskMass + sgLoad) / sgSubjMass) End If 'determine the vo2 required by the activity sgV02ss = V02fastss(sgPhysWorkRate) 'Umin sgV02Fract = sgV02ss / sgAbsV02max sgV02Percent = sgV02Fract * 100 'determine the anaerobic threshold sgRelAnThresh = AT(sgRelV02max) 'ml/kg/min sgAbsAnThresh = sgRelAnThresh * sgSubjMass / 1000 'determine steady-state values for minute volume and tidal volume sgVEss = Vminss(sgV02Percent, sgAbsV02max) 'Umin sgVTss = VTidss(sgV02Percent, sgAbsV02max) 'L If inRespirator = 0 Then 'respirator not worn; no need to adjust parameters 'for external resistance and dead volume sgVEadj = sgVEss sgVTadj = sgVTss sgV02adj = sgV02ss Else 'respirator worn; determine the changes in minute volume 'and tidal volume for resistance and dead volume 'determine the VE and VT with these changes sgVERadj = VERes(sgV02Percent, sgMaskRinh, sgMaskRexh) * 60 'Umin sgVTRadj = VTRes(sgV02Percent, sgMaskRinh, sgMaskRexh) 'L sgVEVDadj = VEVD(sgV02Percent, sgMaskVD) / 60 'Umin sgVTVDadj = VTVD(sgV02Percent, sgMaskVD) 'L sgVEadj = sgVEss + sgVERadj + sgVEVDadj 'Umin sgVTadj = sgVTss + sgVTRadj + sgVTVDadj 'L 'determine the vo2 for respirator wear sgV02adj = V02Adj(sgVEadj) 'Umin End If 'determine the oxygen deficit 'if no respirator is worn, the 02 deficit is zero 460 sg02Deficit = 02Def(sgV02adj, sgV02ss) 'Umin 'determine respiratory rate and respirator period . sgRespRate = RR(sgVEadj, sgVTadj) 'breaths/mm ~gRespPeriod = 1 / (sgRespRate / 60) 'sec determine inhalation and exhalation times sgTexp = Te(sgRespPeriod) 'sec sgTinsp = Ti(sgRespPeriod) 'sec 'determine dimensionless epsilon parameters 'see Johnson ( 1993) for further explanation sgEpsilonl = 1 + (sgTexp / sgTinsp) sgEpsilonE = 1 + (sgTinsp / sgTexp) d 'set the maximum muscle pressure that can be develope 'gender effect is included If sgGender = 0.85 Then sgPmax = 6468 Else sgPmax = 9996 End If '**** * Set Rohrer coefficients '***** values are from Johnson (1993) sgKlaw = 100000 'N s/m"5 - airways sgK2aw = 10000000 'N s"2/m"8 sgK3aw = 125 'N s/m"2 sgKllt = 40000# 'lung tissue sgKlcw = 200000# 'chest wall If sgGender = 0.85 Then . ts myfactor = 0. 7 'if female.increase aw coefficien Else myfactor = 1 End If sgKllaw = sgKlaw / myfactor sgK2Iaw = sgK2aw / myfactor ~gK3Iaw = sgK3aw / myfactor . exhalation aw values are 10% higher sgKlEaw= 1.1 * sgKlaw/myfactor sgK2Eaw = 1.1 * sgK2aw / myfactor sgK3Eaw = 1.1 * sgK3aw / myfactor sgKll = sgKllaw + sgKllt + sgK lcW sgK2I = sgK2Iaw sgK3I = sgK3Iaw sgKlE = sgKlEaw + sgKllt + sgKlcW sgK2E = sgK2Eaw ~gK3E = sgK3Eaw es are affected if a respirator is worn K 1 and K2 valu 'values are for an Ml 7 mask If inRespirator > 0 Then sgK 11 = sgK 11 + 322700 sgKlE = sgK lE + 66290 sgK2I = sgK2I + 5609000o 461 sgK2E- End If - sgK2E + 13760000 sgcom I" sgJn P iance = 0.0000o 1 'm"'SIN sgv en,a = 2600 'N s"'21m"'5 rest - F 'sgVc - sg uncResCap , and sgRV detenrune . . . are entered by the user sgvo· _ 1~1tial lung volumes I - VO,(sgv· C , sgVoe = sgVo· It ap, sgResVol, sgVTadj, sgFuncResCap, sgExtWorkRate) 'L ********* 1 - sgVTadj 'L ******* 'dete · ***************************** 'take ::fi wor~ rate for inhalation and exhalation If sgy02R onn Into account 'use sin er~ent < 40 Then 'less than 40% V02max 'use hybu~oidal wavefonn for inhalation sgRes ;)d _expon~ntial waveform for exhalation sgTinsp, sgtotmh = SmWR2(sgK1I, sgK21, sgK3I, sgCompliance, sgVEadj, sgVTadj, sgRes WR sgVrest, 0, _inRespirator, sgEpsilonI, sgMaskP) sgVrest, 1 ~ E e~h = HybndExp2WR(sgK1E, sgK2E, sgK3E, sgCompliance, sgVEadj, 'sgRe~ t., P~1lonE, _sgVOe, sgVTadj, sgTexp, sgMaskP, inRespirator) sgTinsp, sgf0.Rmh = Sm~2(sgK1I, sgK2I, s~K3I, sgCompliance, sgVEadj, sgVTadj, 'sgRe 1• sgVRest, 0, mRespirator, sgEps1IonI, sgMaskP) sgVRest /PWRe~h = HybridExp2WR(sgK1E, sgK2E, sgK3E, sgCompliance, sgVEadj, Else ' ' sgEpsllonE, sgVOe, sgVTadj, sgTexp, sgMaskP, inRespirator) 'use trap · sgR ezoidal waveform for inhalation and exhalation inRespj espWRinh = Trap3WR(sgK1I, sgK2I, sgK3I, sgCompliance, sgVrest, sgMaskP, . 'sg;:t;r, sg~Tadj, sgTinsp, sgVOi, O, sgVEadj, sgEpsilonl) InRespiratoPWRmh ~ TrapWR(sgKlI, sgK2I, sgK3I, sgCompliance, sgVRest, sgMaskP, If Tr, sgVTadJ, sgTinsp, sgVOi, 0) ~fig exp< 0.66 Then owr . 1mited-hybrid exponential waveform used sgvoe sgRespWRexh = FlowLim2WR(sgK1E, sgK2E, sgKJE, sgCompliance, sglnertia, inResp·i:zVEadj, sgVTadj, sgEpsilonE, 1, sgFuncResCap, sgTexp, sgResVol, sgMaskP, , or, sgPmax, sgVitCap) sgvo sgRespWRexh = FlowLim2WR(sgK1E, sgK2E, sgK3E, sgCompliance, sglnertia, int1e e,_ sgVEadj, sgVTadi sgEpsilonE 1 sgFuncResCap, sgTexp, sgVRest, sgMaskP, ~ Sp1rat 'J • ' ' Else or, sgPmax, sgVitCap) sg!vfas~g~espW~exh = Trap3WR(sgK1E, sgK2E, sgK3E, ~gComp~iance, sgVrest, 's' mRespITator, sgVTadj, sgTexp, sgVOe, 1, sgVEadJ, sgEp~IlonE) Sg!vfaskpgfespw_Rexh = TrapWR(sgKlE, sgK2E, sgK3E, sgCompliance, sgResVol, End 1/Resp,rator, sgVTadj, sgTexp, sgVOe, 1) End If 'detenru . . k Sgt) ne inhalation exhalation and total respiratory wor ~es w ' ' s R P ~xh = sgResp WRexh * sgTexp s:R esp Wmh = sgResp WRinh * sgTinsp s R espW = sgRespWexh + sgRespWinh g esp WR= sgRespW I sgRespPeriod 'total respiratory work, W 462 If sg02 'fin Deficit > 0 Then d rough e t' sgPerIT' s unate of perfonnance time El ime = sgM xD fi . se a e 1c1t / sg02!Jeficit 'minutes I re · 'b sp1rator not worn ecause th '02 defic. ~re are no transient effects, 'by the re" 1.8 zero and performance time is unlimited sgPerIT' sp1ratory system , End If ime = 999999 'minutes ******* this sect' ••••••••••••••••'*•••••••••'** t ******** ********* use to validate the WR eqns '* ion was d ,sgVEad' - ••••••••••••••••••••••••••••• I ****** sgVT ~ - 110 'sgr adJ = 1.833 ' msp = 0 5 ,:gTexp = O.S , gVEadj = 80 .:gV:adj = 1.933 'gTmsp = 0 7 .:gTexp = 0.75 gVOi - s F 'sgVO -:=_ g uncResCap ' e-sgF R sgVO unc esCap 's e=3.72 ' gVitCap = 4 8 ,sgEpsilonl - . ,•gEpsilonE--1 + (sgT~xp I sgTinsp) sgRespWR - 1 + (sgTm~p / sgTexp) . . s VEad' exh = FlowL1mZWR(sgldernaf Work Rate C: [Treadmill Sl)eedandi:i"ia"deJ ---------..;:; Speed (mis) ~ Grade (percent) r ('" Stepping ("' Bicycle Ergometer Done Entering Figure 135. The form for setting the test parameters when treadmill activity is selected. When the treadmill activity is selected, the text box for entering the external work rate di sappears. Similarly, if external work rate is again selected or if stepping 474 b. d d grade text boxes disappear. When the or 1cycle ergometry are selected the spee an user is fini shed setting the test parameters, the button "Done Entering" is clicked and the user is returned to the main form. When the user is finished changing parameters, a simulation may be run by selecting the button "Run Test". If the model is run without changing any of the parameters, the form "Main" will appear as in Figure 136. "!f. ·, ~ ~1 FiieMme rntHe %V02rnax 188.76742 VO 13.4ml4 TettDone7 IALLDONEI VE~[l/minl 1nesm VOe ,1.83672 Selecl Rllll)Slllor I p 2.B9429 VT~lll i,.616584 lriLRllll).WR ,6.081474 VEn(Llminl Set Tut I Pa1-..1 VTn(LJ r, .616584 V02qnted(L/IIW'I) 12796174 Ein. Reap. WR 120.00121 ~WorkRete 1150 VE Rea change ro 02 Dela [l/min) 10 lriL Re;p. W ,4.398921 -lt1J:E1 Efficiency 10.17824 VT Res change 10 Respsation Rate (bpm) 145.09155 Ein. Reap. W 1,214663 ~Wolk 1841.562 Retef'Wl VEVDchange I° lrnalabon Tille (sec) 10.7233315 TotlllReap. \II ps.54555 V02n (llrm) p .796174 VTVD change 10 E>Nlation Tine (sec) jo.6072948 Totl!IReap. WR 11243441 AnM,obic p .215465 Ttveahold {l/.,.;n) r -, Petlonnance Tine - 1999999 I Run Test i Elll I ' ... ! Figure 136. The main form after a simulation has been run with the default parameters. Values appear in the text boxes for each of the respiratory parameters. The performance time for the no respirator condition defaults to 999,999 minutes. Because transient effects were not included, there is no oxygen deficit for the no respirator condition. This means that the performance time would theoretically be infinite. Two output files are generated each time the model is run. The filename 475 may be changed by the user on the form "Main". One file contains the initial values of all the parameters while the other contains all the results. The two output files for the current simulation are shown in Tables 70 and 71. 476 · IrSt output 1le from the mo e s owmg t e m1t1a parameter values. Table 71 The f" f" d l h · h · · · l Start C . . Tria onditions File ****: conducted: 6/13/ 01 6:21 : 51 PM ***** S •••••••••••••• • •• • ••• ••••••••••••••••••••••••••••••••••••• ubject Ch --- aracteristics Ma~; - ~;;~ ------------ Height (m) 70 Age (yr) 1.7 Gender 25 Fitness Male ***** Untrain ed •••••••••••••••• ••••••••••••••••••••••••••••••••••••••••••••••• Ther 1 ___ ma Inputs - --Core T;~;------------- 37 Terr · ** ain Factor 1 ********* ** *********************************** R **** ****** ********** espiratory Inputs ---- ----VO ------- 2 max (L/min) V02max ( v· mL/kg/min ) 3.15 45 4.8 1.2 2.s R~:~l Capacity (L) F idual Volume (L ) uncti R onal Residual capacitY (L) esp. Muse Eff (%) 1c Addit · . · / ) 0 Ad . ional Resp. Res . rnh, (crn!!20/L s A dHional Resp. Re s . Exhh · (crn!l20/L/ 5 l O ddition 1 (L) 0 **** a Resp. ne ad Vol, •••••••••••••••••••******''** ** * ****** ** * * ** ******************** Res · pirator Selec ted None --------'**'** ••••••••••••••••••••••••••••••••••• ************ *** ** ********** ::est Inputs ------Env · ----Rel iron. TeJ!IP. (C ) 22 L · Humidity (%) 60 Eoad Carried (kg ) 0 xternal Work 150 Rate (W) 477 ~able 72. The second file generated by the model showing the results of the simulation. Respiratory Data #1 Trial conducted: 6/13/ 01 6 : 21:51 PM ***************** * ** **************************** ******************** External Work Rate (W) Gross Efficiency (%) Physiological Work Rate (W) Required V02 (L/min ) VE ss (L/min) VT ss (L) VE Resist. Cha nge (L/min) VT Resist. Change (L ) VE Dead Vol. Change (L/min ) VT Dead Vol. Change (L ) Adjusted VE (L/min ) Adjusted VT (L) Adjusted V02 (L/min ) 02 Deficit (L/min) Respiration Rate (bpm) T inh (sec) T exh (sec) %V02max Resp WR inh (W ) Resp WR exh (W) Resp w inh (Nm) Resp W exh (Nm) Total Resp Wo r k (Nm) Resp Wo r k Ra te (W) 150 17.824 841. 562 2.796174 72. 89429 1.616584 0 0 0 0 72. 89429 1.616584 2 . 796174 0 45.09155 0.7233315 0.6072948 88.76742 6.081474 20.00121 4.39 8921 12 . 14663 16.54555 12.43441 478 If a · is s I simulation · · 13/ ected instead of his run wit? the defau!t. values except that the U. S. Anny M40 . t e no respirator condit10n, the fonn will appear as in Figure ~ !~'WflfkA - . .. , llla /r.:15~1.-=-5 - £11· · -IClency ,~0.-17-97-4 - ~""°"' -::--~. rw; /845. 7073 IIOa, tu . r,,.r-~-- n.iJ , 2.00779 ¼er~ T/vethold n , l'-'lllfl) VEw(Llmi,J VTa(I.J /73.41573 /1 .623424 VE Rea change j-18.44046 VT Rea change f o.07472 VE VD change Jo VT VD change I 0 r.::-=; I . •,. ··- - I ___ E_ ... ____ f 89.13588 /3.509418 /1 .811274 VE ~ft/mill f54.97527 VT i,qusted(I.) {1.6$144 VOZ~ft/mi!J /2301359 02 Def'd {Umin) f 0.5$4211 Respiaiion Rate [bp,n) /32.37373 lmalalion Tine(,,c) Ja 9232227 E #llllalion Tine CiecJ Jo.m 316 P«form,,ce Tine u [7.957005 \IOe lnh. RlfP, WR I 6.636767 Ein Rnp. WR f 5.36D1 l lnh. A9$1l. vi j&.127214 /4.985608 Tota Resp. vi I 11.11282 Tola/Resp. WR /5.996/J59 I Figure 137 . D. S. Ann · The mam form after a simulation is run with the default values and the Y M40 respirator. 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