@prefix vivo: . @prefix edm: . @prefix ns0: . @prefix dcterms: . @prefix skos: . vivo:departmentOrSchool "Education, Faculty of"@en, "Kinesiology, School of"@en ; edm:dataProvider "DSpace"@en ; ns0:degreeCampus "UBCV"@en ; dcterms:creator "Koehle, Michael Stephen"@en ; dcterms:issued "2010-01-16T20:15:26Z"@en, "2006"@en ; vivo:relatedDegree "Doctor of Philosophy - PhD"@en ; ns0:degreeGrantor "University of British Columbia"@en ; dcterms:description "Rationale: Intermittent Hypoxia (IH) consists of bouts of hypoxic exposure interspersed with normoxic intervals. In animals, there is some evidence that multiple brief short duration exposures to intermittent hypoxia (SDIH) provoke more profound changes in chemosensitivity than longer duration bouts of intermittent hypoxia (LDIH). The purpose of this study was to test the hypothesis that SDIH would have differential effects from LDIH on chemosensitivity during rest and exercise in humans. Methods: Ten males underwent two intermittent hypoxic protocols of 7 days duration/each. The LDIH protocol consisted of daily 60-minute exposures to normobaric 12% O₂. The SDIH protocol consisted of twelve 5-minute bouts of normobaric 12% O₂, separated by 5-minute bouts of normoxia. Measured resting variables included the hypoxic ventilatory response (HVR), hypercapnic ventilatory response (HCVR), CO₂ threshold and CO₂ sensitivity. Submaximal exercise variables included minute ventilation, oxygen saturation, hyperoxic and hypercapnic ventilatory response in both hypoxia and normoxia. Peak exercise variables included power and oxygen consumption in hypoxia. Measurements were made immediately prior to intermittent hypoxic training and on the first day following IH. Resting measures were repeated 7 days following IH. Results: For both protocols, the HVR was significantly (p< 0.05) increased after IH. One week post IH, the HVR was not different from pre-IH. The HCVR was increased and remained elevated at 7 days post-IH (p<0.01). The CO₂ sensitivity was unchanged by either intervention. In hypoxia and hyperoxia, the CO₂ threshold was significantly reduced following IH (p<0.05). The submaximal minute ventilation, hyperoxic and hypercapnic responses in normoxia and hypoxia were unchanged by IH. Submaximal oxygen saturation and peak power were both increased (p<0.05), while maximal ventilation and oxygen consumption were unaltered. There were no significant differences between the two IH protocols for any of the above measures. Conclusions: A 7-day IH protocol causes increases in the HVR and HCVR at rest and a left-shift in the CO₂ threshold and an improvement in oxygen saturation during submaximal hypoxic exercise. SDIH is no more efficacious than LDIH at effecting these changes in respiratory control."@en ; edm:aggregatedCHO "https://circle.library.ubc.ca/rest/handle/2429/18434?expand=metadata"@en ; skos:note "INTERMITTENT HYPOXIA AND THE C H E M O R E F L E X C O N T R O L OF BREATHING by MICHAEL S T E P H E N K O E H L E B.Sc.H., Queen's University at Kingston, 1993 M . S c , The University of Toronto, 1995 M.D., The University of Toronto, 1999 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE D E G R E E OF DOCTOR OF PHILOSOPHY in THE F A C U L T Y OF G R A D U A T E STUDIES (Human Kinetics) THE UNIVERSITY OF BRITISH COLUMBIA August 2006 © Michael Stephen Koehle, 2006 ABSTRACT Rationale: Intermittent Hypoxia (IH) consists of bouts of hypoxic exposure interspersed with normoxic intervals. In animals, there is some evidence that multiple brief short duration exposures to intermittent hypoxia (SDIH) provoke more profound changes in chemosensitivity than longer duration bouts of intermittent hypoxia (LDIH). The purpose of this study was to test the hypothesis that SDIH would have differential effects from LDIH on chemosensitivity during rest and exercise in humans. Methods: Ten males underwent two intermittent hypoxic protocols of 7 days duration/each. The LDIH protocol consisted of daily 60-minute exposures to normobaric 12% O2. The SDIH protocol consisted of twelve 5-minute bouts of normobaric 12% O2, separated by 5-minute bouts of normoxia. Measured resting variables included the hypoxic ventilatory response (HVR), hypercapnic ventilatory response (HCVR), C 0 2 threshold and CO2 sensitivity. Submaximal exercise variables included minute ventilation, oxygen saturation, hyperoxic and hypercapnic ventilatory response in both hypoxia and normoxia. Peak exercise variables included power and oxygen consumption in hypoxia. Measurements were made immediately prior to intermittent hypoxic training and on the first day following IH. Resting measures were repeated 7 days following IH. Results: For both protocols, the HVR was significantly (p< 0.05) increased after IH. One week post IH, the HVR was not different from pre-IH. The HCVR was increased and remained elevated at 7 days post-IH (p<0.01). The CO2 sensitivity was unchanged by either intervention. In hypoxia and hyperoxia, the CO2 threshold was significantly reduced following IH (p<0.05). The submaximal minute ventilation, hyperoxic and hypercapnic responses in normoxia and hypoxia were unchanged by IH. Submaximal oxygen saturation and peak power were both increased (p<0.05), while maximal ventilation and oxygen consumption were unaltered. There were no significant differences between the two IH protocols for any of the above measures. Conclusions; A 7-day IH protocol causes increases in the HVR and HCVR at rest and a left-shift in the CO2 threshold and an improvement in oxygen saturation during submaximal hypoxic exercise. SDIH is no more efficacious than LDIH at effecting these changes in respiratory control. ii TABLE OF CONTENTS Abstract • ii Table of Contents iii List of Tables vi List of Figures viii Co-authorship Statement x Chapter 1 - Introduction 1 Proposed Mechanism of Intermittent Hypoxia.. 2 Duration of Intermittent Hypoxia 8 Hypobaric vs. Normobaric Intermittent Hypoxia 8 Poikilocapnia vs. Isocapnia 8 Hypoxia Duty Cycle 9 Responses to Carbon Dioxide and Intermittent Hypoxia 10 Respiratory Drive during Exercise 12 Summary 14 Research Questions 15 Hypotheses 17 Purpose 17 References 18 Chapter 2 - Repeated Measurements of Hypoxic Ventilatory Response as an Intermittent Hypoxic Stimulus 23 Research Question 24 Methods 24 Data and Statistical Analysis 26 iii Results 26 Discussion 32 Methodological Considerations. 34 Conclusions 35 References 36 Chapter 3 - Intermittent Hypoxia and its Effect on Resting Measures of Chemoresponse 38 Research Questions 39 Methods 39 Hypoxic Ventilatory Response 42 Hypercapnic Ventilatory Response 44 Modified Rebreathing 45 Intermittent Hypoxic Training 47 Follow-up 48 Statistics 49 Results 49 Hypoxic Ventilatory Response 50 Modified Rebreathing 54 Hypercapnic Ventilatory Response 56 Associations between Chemosensitivity Measures 57 Discussion 58 Hypoxic Ventilatory Response 58 Hypercapnic Ventilatory Response 59 Modified Rebreathing 59 SDIH vs. LDIH 63 Limitations 65 Conclusions 66 References 67 iv Chapter 4 - Intermittent Hypoxia and its Effect on Exercise Chemosensitivity...69 Research Questions • • .70 Methods 70 Exercise Test 71 Intermittent Hypoxia Protocol 74 Follow-up 74 Data Analysis 75 Results 75 Submaximal Exercise Test 75 Hypoxic Graded Exercise Test 78 Discussion 81 Minute Ventilation During Normoxic Exercise 81 Minute Ventilation During Hypoxic Exercise 83 Hyperoxic Test 85 Hypercapnic Test 87 Oximetry during Submaximal Exercise 88 Maximal Exercise Test 89 SDIH vs. LDIH 90 Limitations 91 Conclusions 92 References. 93 Chapter 5 - Conclusions 96 References 100 Appendix I - Certificates of Ethical Review 103 Appendix II - Informed Consent Forms 107 Appendix III - Physical Activity Readiness Questionnaire 116 Appendix IV- Data Tables 118 LIST OF TABLES 1.1: Summary of selected research on intermittent hypoxic training and ventilatory control in humans 5-7 2.1: Anthropometric and spirometry data for all subjects 27 2.2: Resting respiratory parameters and hypoxic ventilatory response (HVR)...28 3.1: Anthropometric, Respiratory and Exercise Baseline Data 50 4.1: Exercise Minute Ventilation Pre- and Post-Intermittent Hypoxia (IH) 75 4.2: Mean decreases in Minute Ventilation following 3 breaths of hyperoxia (Pre-and Post-IH) 76 4.3: Mean increases in Minute Ventilation following 1 breath of hypercapnia (Pre-and Post-IH) 77 6.1: HVR Results during the SDIH protocol.... 119 6.2: HVR Results during the LDIH protocol 120 6.3: HCVR Results during the LDIH and SDIH protocols 121 6.4: Hypoxic modified rebreathing method results during the LDIH and SDIH protocols 122 6.5: Hyperoxic modified rebreathing method results during the LDIH and SDIH protocols .123 6.6: Submaximal minute ventilation values during exercise before and after SDIH , 124 6.7: Submaximal minute ventilation values during exercise before and after LDIH 125 6.8: Submaximal saturation values during hypoxic exercise 126 v i 6.9: Hyperoxic Test ventilation values during normoxic exercise before and after SDIH 127 6.10: Hyperoxic Test ventilation values during normoxic exercise before and after LDIH '. 128 6.11: Hypercapnic Test ventilation values during normoxic exercise before and after SDIH .....129 6.12: Hypercapnic Test ventilation values during normoxic exercise before and after LDIH .....130 6.13: Hyperoxic Test ventilation values during hypoxic exercise before and after SDIH 131 6.14: Hyperoxic Test ventilation values during hypoxic exercise before and after LDIH 132 6.15: Hypercapnic Test ventilation values during hypoxic exercise before and after SDIH 133 6.16: Hypercapnic Test ventilation values during hypoxic exercise before and after LDIH 134 6.17: Peak Ramp time, oxygen consumption V 0 2 and ventilation during a graded exercise test in hypoxia and after SDIH 135 6.18: Peak Ramp time, oxygen consumption V 0 2 and ventilation during a graded exercise test in hypoxia and after LDIH 136 vii LIST OF FIGURES 2.1: Sample data from one HVR test on one subject 29 2.2: HVR plot using the data from Figure 2.1 31 2.3: Summary plot of all HVR results for all subjects 32 3.1 Study Paradigm 41 3.2 Sample data from an individual modified rebreathing test 47 3.3: Mean (±SD) Hypoxic Ventilatory Response (HVR) vs. Time 51 3.4: Individual Hypoxic Ventilatory Response (HVR) vs. Time during the LDIH Protocol. Thick black line denotes mean response 52 3.5: Individual Hypoxic Ventilatory Response (HVR) vs. Time during the SDIH Protocol. Thick black line denotes mean response 53 3.6: Mean (+SD) Hypoxic Ventilatory Response (HVR) vs. Time by Protocol Order.. 53 3.7: Mean (±SD) Carbon dioxide Threshold in Hyperoxia vs. Time 55 3.8: Mean (±SD) Carbon dioxide Threshold in Hypoxia vs. Time 55 3.9: Mean (±SD) Hypercapnic Ventilatory Response (HCVR) vs. Time 57 4.1 Exercise Testing Protocol.... 72 4.2: Mean (±SD) Oxygen Saturation (%) during Submaximal Hypoxic Exercise vs. Intermittent Hypoxia Protocol 78 v i i i 4.3: Mean (±SD) Peak Wattage vs. Intermittent Hypoxia Protocol 79 4.4: Mean (±SD) Peak Oxygen Consumption (L#min\"1) vs. Intermittent Hypoxia Protocol 80 4.5: Mean (±SD) Peak Exercise Ventilation (L»min~1) vs. Intermittent Hypoxia Protocol 80 ix CO-AUTHORSHIP S T A T E M E N T A version of Chapter 2 has been previously published as; Koehle MS, Foster G E , McKenzie DC and Sheel A W (2005) Repeated measurement of hypoxic ventilatory response as an intermittent hypoxic stimulus Resp Phys io l Neurobiol 145(1): 33-39. MS Koehle was the primary author and played the principal role in identification and design of the research programme, performance of research, data analysis and manuscript preparation. G E Foster assisted in the performance of research. DC McKenzie assisted in identification and design of the research programme and manuscript preparation. A W Sheel assisted in identification and design of the research programme, data analysis and manuscript preparation. CHAPTER 1: INTRODUCTION The term Intermittent Hypoxia (IH) refers to an exposure to multiple brief bouts of hypoxia over a period of time. This length of time can be as short as a few minutes or as long as several weeks. IH has been shown to increase red cell mass 1 , blood pressure 2 and cerebrovascular and sympathetic responses to hypoxia 3 4 . IH can cause alterations in the chemoreflex control of breathing in humans that may have potential clinical or ergogenic applications. There is some evidence that it may protect the heart from ischaemia and have the potential to improve ventilation in spinal cord transection patients6. For the respiratory system, IH can increase an individual's ventilatory response to hypoxia at rest 7\" 1 1. There is some evidence that IH can also increase exercise ventilation during exercise tests at simulated altitude (4500 metres) 1 2. This increased ventilation is associated with improved arterial oxygen saturation during exercise. IH does not appear to increase exercise ventilation at sea level 1 3 . However, although no research has examined exercise ventilation at sea level and simulated altitude following the same IH exposure. Proposed Mechanism of Intermittent Hypoxia Due to its invasive nature, the majority of the research into the mechanism of IH has been performed in animal models. These concepts are applied to human physiology with appropriate caution. Acute hypoxic exposure leads to a series of alterations in neural control of respiration; these are the short-term hypoxic phrenic response, the post-hypoxia frequency decline and phrenic Long-term Facilitation (LTF). The short-term hypoxic phrenic response is an increase 2 in integrated phrenic amplitude during the hypoxic exposure. This modulation does not persist beyond the hypoxic exposure, but it can be augmented by intermittent hypoxia through a serotonin-mediated mechanism 1 4 . Following the hypoxic exposure, a transient decrease in phrenic motorneuron frequency occurs that returns to baseline after several minutes. 1 4 Subsequent to the hypoxic exposure, there is a persistent increase in phrenic motorneuron output amplitude lasting minutes to hours, termed the phrenic L T F 1 5 . LTF following an acute hypoxic exposure is a form of neural \"plasticity\". Plasticity is defined as \"a persistent change in the neural control system based on prior experience\" 1 6. With repeated exposures to hypoxia (intermittent hypoxia) this increased phrenic motorneuron output (LTF) is further augmented 1 4. This amplification of the LTF is believed to be a form of \"metaplasticity\" whereby a prior exposure (to hypoxia) modifies one's ability to express plasticity1 6. This metaplasticity can be blocked using the serotonin blocker methysergide 1 4, indicating that the mechanism is at least partially serotonin-mediated. Other mechanisms may also play a role in the generation of LTF, such as the nitric oxide pathway 1 5. Following intermittent hypoxia, the augmented LTF can be induced with either hypoxia or electrical carotid sinus nerve stimulation, indicating that this plasticity occurs (at least partially) through central facilitation of chemoreceptor afferents as opposed to occurring entirely at the carotid peripheral chemoreceptors themselves 1 4 . LTF can occur in response to hypoxia in carotid-denervated cats, indicating that there may be a possible role for the direct effect of hypoxia on the C N S neurons themselves. 1 7 3 Duration of Intermittent Hypoxia Many different IH protocols have been utilized in previous studies in humans (see Table 1.1). Exposures have ranged from twenty minutes to two hours in length, and have typically been repeated between 7 and 14 times. The optimal IH intervention for increasing hypoxic ventilatory response is unknown. One way to better characterize the minimum duration of IH on ventilation would be to measure hypoxic ventilatory response (HVR) daily during the administration of an IH regime. When working with hypoxia and hypoxic sensitivity, one must be careful to ensure that the measurements used in a study are not interventions themselves. During a single HVR test, a subject receives a short exposure to significant hypoxia (lasting approximately 5 minutes) where F|0 2 (fraction of inspired oxygen) can reach as low as 5%. An HVR test therefore represents a shorter but more severe hypoxic exposure than the typical bout of hypoxia used during IH. It is possible that the brief, more profound exposures of an HVR test, if repeated daily, could present an intermittent hypoxic stimulus and therefore affect ventilation during subsequent hypoxic exposures. Before incorporating daily assessment of HVR into a study, the significance of this potential co-intervention would need to be assessed. 4 Paper N Intervention Testing HVR HCVR HCVR sb Modified Read Rebreathe V02max Exercise Ventilation Haem. Comments Foster et al. 200618 9JSDIH 9c?LDIH Normobaric 12%02 10 of 12 days SDIH/LDIH -V02max, min Ve, Fb at various %max N/A N/A N/A N/A -OA (at sea level) -0A (at sea level) N/A -isocapnic Townsend et al.20058 12c?A 11c?B 10c?C Normobaric 16.3 %02 A=20dX8-10h B=4 X (5d X 8-10h) C=Control -HVR (pre-, Post-) -submaximal exercise Ve (Pre-, after 4,10 19 nights) -increased in both IH groups N/A N/A N/A N/A -increased after 4 nights of hypoxia for both IH groups N/A -exercise ventilation measured in normoxia -change in exercise ventilation correlated to change in HVR Foster et al. 20057 9£S - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Natural Science Engineering Research Council wu Intermittent Hypoxia and the Chemoreflex Control of Ventilation K--UH.U *.t IN 'tf* W W i 11 Aug 2004 1 Protocol: Consent version 1.1 dated 2\" My 2004: Advertisement: PAR-Q Qjies&onnaire In r*«p*ct of clinical trials: 1 The membership of this Research Etftci Board complies mth the membership requirements for Research Ethics Boards defined in Dwswn 5 of the Food and Drug Regulations 2. The Research Ethics Board cames out its functions m a manner consistent with Good Clinical Practices. 3. This Research Ethics Board has reviewed and approved She clinical trial protocol and informed consent form for the tnal *hteft is to be conducted by the qualified investigator named above at the specified clinical trial site This approvai and the views of the this Research Ethics Board have been documented in writing The doc-mentation included fortne above-named project has been reviewed by the Chair of the JBC CREB and the research study, as preserteo* in trie documentation, was found to be acceptable on ethical grounds for research invcvmg human subjects and was approved by the UBC CREB. The CREB approval for this study expires one year from the approval date. Approval of the Clinical Research Ethics Board by one of Dr P. Loewen. Chair Dr. A. Gaenon, Associate Chair Dr. J. McCormack. Associate Chair UBC The University of British Columbia Office of Researcn Services. Ciimcal Research Ethics Board - Room 210 S23 'A'est 10* Avenue. Vancouver, BC VEZ 1LS 105 [UBC w The University of British Columbia Office of Research Services, Clinical Research Ethics Board - Room 210 328 West 10* Avenue, Vancouver. BC V S 2 1L3 Certificate of Expedited Approval: Renewal Clinical Research Ethics Board Official Notification lnwin-A. w t s W o * -mnrrstm McKenzie. D.C. C04-0402 UBC Campus <.04hVt£tO*IO>(S — — — Guenette. Jordan.: Hughes. Bevan.: Koehle. Michael. Human Kinencs; Lu5ina. Sarah. Human Kinetics: Milsom. William. Zoology. Sheet. William. Human Kinetics Natural Science Engineering Research Council Intermittent Hypoxia and the Chemoreflex Control of Ventilation 11HM imMi:— tMN'-'UtrHf 19 July 2005 1 hi raepect or clinical trtaia: 1. The membership of this Research Ethics Board complies with the membership requirements for Research Ethics Boards defined in Division 5 cf the Food and Drug Regulations 2 The Research Ethics Board cames out ns functions m a manner consistent frith Good Clinical Practices. 3. This Research Ethics Board has reviewed and approved the dinical tnal protocol and informed consent form hr the trial mlvch is to be conducted by the qualified investigator named above at the specified c'm<:ai trial site This approval and the views of this Research Ethics Board have been documented in t/rritmg The Chair of the UBC Clinical Research Ethics Board has reviewed the documentation for the above named project. The research study, as presented in the documentation, was found to be acceptable on ethical grounds for research involving human subjects and was approved for renewai by the UBC Clinical Research Ethics Board The CREB approval for renewal of this study expires one year from the date of renewal. Approval of the Clinical Reseanh Ethics Board by one of Dr Gail BellwardL Chair Dr. James McCormack. Associate Chair 106 APPENDIX II: Informed Consent Forms capable o f inducing haematological changes, such as increases in the ability of the blood to carry oxygen. The ideal protocol is not yet known. In animals, multiple short bouts (less than 5 minutes) each day has been shown superior to single long daily bouts. This has not been examined in humans. Likewise the ideal length of an IHT protocol is also unknown. This study w i l l attempt to answer these questions. Purpose: The purpose o f this study is to investigate the breathing response to hypoxia over seven daily hypoxic ventilatory response tests. Procedures: A l l subjects recruited for the study w i l l be normal healthy male volunteers, between 18-40 years of age. A l l subjects w i l l be non-smoking, have normal pulmonary function and free o f any history or symptoms of cardiopulmonary disease including exercise-induced asthma. Subjects w i l l not have had any significant exposure to altitude or hypoxia in the preceding four weeks. Each subject w i l l undergo a standardized screening history (Physical Activi ty Readiness Questionnaire; P A R - Q ) . If you consent to become a subject in this study you w i l l be asked to participate in nineteen data collection test days. The session w i l l take place at the Health and Integrated Physiology Laboratory at the Osborne Centre (Unit 2, Room 202) on the University of British Columbia campus. The study w i l l require approximately thirty-four (34) hours of your time. We w i l l schedule your testing sessions to be most convenient for you. On the first day, your height and weight w i l l be measured. Y o u w i l l then undergo a simple, non-invasive breathing test to ensure that you do not have any obstructive lung disease (i.e., asthma). This requires you to breathe deeply and exhale quickly through a mouthpiece. Y o u w i l l then be required to lie comfortably on a bed in which you w i l l breath through a two-way valve so that expired gases and flow can be monitored. A small plastic clip w i l l slip onto your fingertip. This w i l l permit us to measure the amount o f oxygen in your blood. After 10 minutes of breathing normal air, experimenters w i l l slowly and progressively add nitrogen gas to the air you are breathing. We wi l l measure the amount that your breathing (rate and depth) increases in response to this. The test w i l l stop once your blood oxygen saturation level reaches 80%. This experiment w i l l simulate high altitude exposure and w i l l take approximately 15 minutes. This is the hypoxic ventilatory response ( H V R ) test. Y o u w i l l then perform a similar test where you breathe from a large bag while resting. We w i l l control the concentration of gases in the bag. Gradually the carbon dioxide in the bag w i l l accumulate, and you w i l l breathe more and more. We w i l l stop the test once it has become too uncomfortable or the amount o f carbon dioxide in the bag reaches a pre-determined amount (60 mmHg). This is the hypercapnic ventilatory response test ( H C V R ) . 109 The next test is the maximal oxygen uptake test. This is a test where you ride a stationary bicycle while wearing a mask to collect the gas that you breath out. The resistance on the bicycle gets higher and higher until you can no longer continue. This test determines aerobic fitness. On your second visit, you w i l l repeat the H V R test and the H C V R test. Y o u wi l l also complete the multi-stage exercise test. During this test, you w i l l be exercising on a bicycle at two relatively low resistances. Y o u w i l l first exercise breathing room air, and then secondly while breathing hypoxic air. Y o u wi l l finish the exercise test by performing another maximal oxygen uptake test (while breathing the hypoxic gas). A l l your pre-testing is complete. Y o u wi l l then start your intermittent hypoxic training (IHT). This w i l l last for 7 days. Y o u wi l l do two different protocols, and they w i l l each last seven days. Each day you w i l l come to the lab, and breath a gas mixture while relaxing, watching movies, reading or working quietly. Each time you come in you w i l l also do an H V R test. A t the end o f each 7-day IHT session we w i l l repeat the H V R , H C V R and multi-stage exercise test. Y o u w i l l do each IHT programme at least 2 weeks apart. One week after each I H T programme, you w i l l return to the lab and H V R and H C V R w i l l be re-measured. Risks: There are no significant risks associated with a short exposure to simulated altitude (approximately 20,000 feet). A physician (Dr. Koehle or Dr. Hughes) w i l l be present at all testing sessions, i f you feel any discomfort, or have any concerns, you wi l l be attended to immediately. Some people find it feels a little uncomfortable when they are breathing hypoxic air. The maximal oxygen uptake test has a small chance o f adverse effects, such as vomiting (5%), abnormal blood pressure (less than 1%). fainting (less than 1%), disorders of the heartbeat (less than 0.1%). and very rare instances o f heart attack (less than 0.001%). A l l procedures used in this study have been previously performed i n our laboratory without incident. Benefits: B y participating in the study, the subjects w i l l enhance the understanding of the effects of hypoxia on the control of breathing; this knowledge w i l l be used to further our understanding of the safety of diving in the asthmatic population. Furthermore, you w i l l receive a maximal oxygen uptake test (V02max test) and two courses of intermittent hypoxic training at no charge. After completion of the study, you w i l l receive an honorarium of one hundred dollars. Confidentiality: Your rights to privacy are protected by the Freedom of Information and Protection of Privacy Act o f British Columbia This Ac t lays down rules for the collection, protection, and retention o f your personal information by public bodies, such as the University of British Columbia and its affiliated teaching hospitals. Further details about this Ac t are available upon request. Your confidentiality w i l l be respected. N o information that 110 discloses your identity w i l l be released or published without your specific consent to the disclosure. However, research records and medical records identifying you may be inspected in the presence o f the Investigator or his or her designate by representatives o f the U B C Research Ethics Board for the purpose of monitoring the research. However, no records which identify you by name or initials w i l l be allowed to leave the Investigators' offices. Y o u are encouraged to ask for an explanation or clarification of any o f the procedures or other aspects of this study before signing this consent from or at any time during your participation in the study. Y O U M A Y D E C L I N E T O E N T E R THIS S T U D Y O R W I T H D R A W F R O M T H E E X P E R I M E N T A T A N Y T I M E . If you have any concerns or questions about your rights or experience as a research subject, you may contact the Research Subject Information Line in the U B C Office of Research Services at (604) 822-8598. Consent: In signing this form you are consenting to participate in this research project and acknowledge receipt of a copy of this form. Signing this consent form in no way limits your legal rights against the sponsor, investigators, or anyone else. Signature of Participant Date Printed Name of Participant Signature of Witness Date Printed Name of Witness Signature of Investigator Date Printed Name of Investigator 111 (less than 5 minutes) each day has been shown superior to single long daily bouts. This has not been examined in humans. Likewise the ideal length of an IHT protocol is also unknown. This study w i l l attempt to answer these questions. Purpose: The purpose o f this study is to investigate the breathing response to hypoxia over seven daily hypoxic ventilatory response tests. Procedures: A l l subjects recruited for the study w i l l be normal healthy male volunteers, between 18-40 years of age. A l l subjects w i l l be non-smoking, have normal pulmonary function and free of any history or symptoms of cardiopulmonary disease including exercise-induced asthma. Subjects w i l l not have had any significant exposure to altitude or hypoxia in the preceding four weeks. Each subject w i l l undergo a standardized screeriing history (Physical Activi ty Readiness Questionnaire; P A R - Q ) . If you consent to become a subject in this study you w i l l be asked to participate in nineteen data collection test days. The session w i l l take place at the Health and Integrated Physiology Laboratory at the Osborne Centre (Unit 2, Room 202) on the University of British Columbia campus. The study w i l l require approximately thirty-four (34) hours of your time. We w i l l schedule your testing sessions to be most convenient for you. On the first day, your height and weight w i l l be measured. Y o u wi l l then undergo a simple, non-invasive breathing test to ensure that you do not have any obstructive lung disease (i.e., asthma). This requires you to breathe deeply and exhale quickly through a mouthpiece. Y o u w i l l then be required to lie comfortably on a bed in which you w i l l breath through a two-way valve so that expired gases and flow can be monitored. A small plastic clip w i l l slip onto your fingertip. This w i l l permit us to measure the amount o f oxygen in your blood. After 10 minutes of breathing normal air, experimenters w i l l slowly and progressively add nitrogen gas to the air you are breathing. We w i l l measure the amount that your breathing (rate and depth) increases in response to this. The test w i l l stop once your blood oxygen saturation level reaches 80%. This experiment w i l l simulate high altitude exposure and w i l l take approximately 15 minutes. This is the hypoxic ventilatory response ( H V R ) test. Y o u w i l l then perform a similar test where you breathe from a large bag while resting. We w i l l control the concentration of gases in the bag. Gradually the carbon dioxide in the bag w i l l accumulate, and you w i l l breathe more and more. We w i l l stop the test once it has become too uncomfortable or the amount of carbon dioxide in the bag reaches a pre-determined amount (60 mmHg). This is the hypercapnic ventilatory response test ( H C V R ) . 113 The next test is the maximal oxygen uptake test. This is a test where you ride a stationary bicycle while wearing a mask to collect the gas that you breath out. The resistance on the bicycle gets higher and higher until you can no longer continue. This test determines aerobic fitness. O n your second visit, you w i l l repeat the H V R test and the H C V R test. Y o u w i l l also complete the multi-stage exercise test. During this test, you wi l l be exercising on a bicycle at two relatively low resistances. Y o u w i l l first exercise breathing room air, and then secondly while breathing hypoxic air. Y o u wi l l finish the exercise test by performing another maximal oxygen uptake test (while breathing the hypoxic gas). A l l your pre-testing is complete. Y o u w i l l then start your intermittent hypoxic training (IHT). This w i l l last for 7 days. Y o u w i l l do two different protocols, and they w i l l each last seven days. Each day you w i l l come to the lab, and breath a gas mixture while relaxing, watching movies, reading or working quietly. Each time you come in you w i l l also do an H V R test. A t the end o f each 7-day IHT session we w i l l repeat the H V R , H C V R and multi-stage exercise test. Y o u w i l l do eachTHT programme at least 2 weeks apart. One week after each IHT programme, you w i l l return to the lab and H V R and H C V R w i l l be re-measured. , Risks: There are no significant risks associated with brief mild hypoxia exposure (approximately 20,000 feet). A physician (Dr. Koehle or Dr. Hughes) w i l l be present at all testing sessions, i f you feel any discomfort, or have any concerns, you w i l l be attended to immediately. Some people find it feels a little uncomfortable when they are breathing hypoxic air. The maximal oxygen uptake test has a small chance o f adverse effects, such as vomiting (5%), abnormal blood pressure (<1%), fainting (<1%), disorders of the heartbeat (<0.1%), and very rare instances of heart attack (<0.001%). A l l procedures used in this study have been previously performed in our laboratory without incident. Benefits: B y participating in the study, the subjects w i l l enhance the understanding of the effects o f hypoxia on the control of breathing; this knowledge w i l l be used to further our understanding o f the safety o f diving in the asthmatic population. Furthermore, you w i l l receive a maximal oxygen uptake test (V02max test) and two courses of intermittent hypoxic training at no charge. After completion of the study, you w i l l receive an honorarium of one hundred dollars. Confidentiality: Your rights to privacy are protected by the Freedom o f Information and Protection of Privacy Ac t of British Columbia, This Ac t lays down rules for the collection, protection, and retention o f your personal information by public bodies, such as the University o f British Columbia and its affiliated teaching hospitals. Further details about this Ac t are available upon request. Your confidentiality w i l l be respected. N o information that discloses your identity w i l l be released or published without your specific consent to the disclosure. However, research records and medical records identifying you may be 114 inspected in the presence of the Investigator or his or her designate by representatives of the U B C Research Ethics Board for the purpose of monitoring the research. However, no records which identify you by name or initials w i l l be allowed to leave the Investigators' offices. Y o u are encouraged to ask for an explanation or clarification of any of the procedures or other aspects o f this study before signing this consent from or at any time during your participation in the study. Y O U M A Y D E C L I N E T O E N T E R THIS S T U D Y O R W I T H D R A W F R O M T H E E X P E R I M E N T A T A N Y T I M E . If you have any concerns or questions about your rights or experience as a research subject, you may contact the Research Subject Information Line in the U B C Office of Research Services at (604) 822-8598. Consent: In signing this form you are consenting to participate in this research project and acknowledge receipt o f a copy of this form. Signing this consent form in no way limits your legal rights against the sponsor, investigators, or anyone else. Signature of Participant Date Printed Name of Participant Signature of Witness Date Printed Name of Witness Signature of Investigator Date Printed Name of Investigator 115 APPENDIX III: Physical Activity Readiness Questionnaire 116 frevfced&B) PAR-Q & YOU (A Questionnaire for People Aged 15 te 69) Heguter pjipical MES? / e fun ind heafihy, and irtoeasmarr snore psopte are stating to beams mere ac.iie srvery day Being more aaae is very safe ior most paaple. :-to,»?i-e-r, some people should check sr-h tSieir doctor before they sart bacsimng irrudi more physicElrjr active. E ira i*9 farming to secoms much mors pbysxaDy ear/9 Chan joa ere now, start by sewing tie seven questions in the ben beta* B you are bsraean ths a§asof 1 Sand 69. the SW-Q w3l tell jou if ymrshaiM died wife your doaor beta you start If ytraswovar&'SyBarsol age, and you are not used to being wry scwe, died wilh your doom Common tense is your best guide whan you answer these qussocre. Please read ths questions CBrefuuy aid answer each one honesty: check YES cr KO. res N O • • t . • • 2. • • 3, • • 4. • • S. • • e. • • 7. Has year doctor ever said that yen have a heart condition and that yea should only de physical activity recommended by a doctor? De yea feel pain in year chest when yea do physical activity? ID the past month, have yoo had chest pain when yen sere net doing physical activity? De yea lose your balance became et dizziness or de yea ever lese consciousness? De yea have a bone or joint problem (far eiample, bach, fcnee or hip) thai could be made worse by a change in year physical activity? Is your doctor currently preicrrbbo drags (fei example, water pills) for your bleed pressure er heart con-dition? De yen know ef aw ether reason why yen should net de physical activity? If you answered YES to one or more questi Talk Atth pur doctor ay pfcens crfe parson 3EF0FE p u start becctring such men gkj/zto&f BTDW cr EcFCRE yoy hstti a Stress appraisal. Isti ycur dbctsr about the PMHJ 2nd which quaciraB ycu a r e « r e d YES. • Ycu rray he aifo to do any xzjri.ty you want— as Inng ss ycu siart sfcwty UP ffraduaf^ Cr, yirj may need :o reSTirt pur adidte; to dtcse o^ sch S7e safe fer you. Talk nrtrt your doctor stout the khds cf tctrrtins p u wish to por^ cbats in and icilc* holier actfea. • nrtd out which tntmtifuijr prograres are safe and IndbAil fcr yoa_ NO to all questions O S L A T B E C O M I N G M U C H R O B E A C T I V E : - IJ yaa a » rwc fee3ag • s f l bocaiaff cf a t B i t p c r a r y a n s s s s u c h a s a cok) cr s fcwr- mst urei pu fed better; ar * if pu are or may be pregnane-tall tu your doctcr barcre pu stan baemthg rocrg aicu«. tf you answered HO fecnststJ/ ta all flAft< gjsstixsv pu can be raasonanV aire that ycu can: • scan iwccrrinj such nxra cfcyscaly actna - begin SIS-AI / and inftf up gradual}/ Ihc b the safest and eases: way to ga • take part h a fJteess appraisal— ths ts an excellent way to datorafee pur basic £biess so ftalpacanptrnthst^wayfarpu to he aAM*}/ fto alst highly /•rafrrnsjiCBd lha* yaa haws ycur Stoxi pressure evaluated. 2 pur reading is ever 144f94, tdk with pur &ctef bsfcre ycu start becKnirg micfi room physicafy iHrrc. P I E A S E N O T E : IF pur haarT\". dongas sc that ycrj then ans-rvcr YE5 :a any of th? above qnKfanns, td\\ yxr£rneu cr h=aeh prtricscnai. Ask 'tvhethsr pu shoJd change year physkal activity plan. He changes permitted. Toil are encouraged te photocopy the PAR-Q bat only if yea use (he entire form, 1 nave read, understood and completed this questionnaire. Any cntessceis I had wars anseered to UI sabsfactim.* mm 99K? . IE am Hate: Tbb physical activity etc ex once is valid fnor a Biaiisntiaa of 12 maatbs from tlie date it b completed and becomes invalid if your condition cfaages so tliat yon would answer TES to any of the seven cjuestknts. ® CansdzD SccTirty fcr Ectyose Ptyzkhq$ Suppcrledtr^ Canada C i^riada ccfitnueQ >cm other sirfs... 117 APPENDIX IV: Data Tables Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8 Day 14 Subject HVR R 2 HVR R 2 HVR R 2 HVR R 2 HVR R 2 HVR R 2 HVR R 2 HVR R 2 HVR R 2 1 0.24 0.32 0.36 0.66 0.41 0.43 0.56 0.63 0.36 0.77 0.41 0.51 0.41 0.61 0.33 0.49 0.39 0.59 2 0.43 0.83 0.26 0.65 0.25 0.67 0.62 0.88 0.75 0.83 0.35 0.69 0.59 0.89 0.66 0.84 0.71 0.48 3 0.22 0.35 0.30 0.45 0.62 0.64 0.54 0.58 0.41 0.57 0.43 0.48 0.68 0.59 0.73 0.58 0.56 0.50 4 0.24 0.41 0.33 0.57 0.28 0.40 0.42 0.66 0.46 0.43 0.72 0.91 0.52 0.74 0.49 0.71 0.47 0.78 5 0.67 0.59 0.84 0.63 0.97 0.32 0.82 0.81 1.11 0.82 0.63 0.67 0.79 0.63 0.65 0.75 0.82 0.69 6 0.46 0.35 0.46 0.33 0.47 0.66 0.41 0.38 0.45 0.60 0.61 0.61 0.68 0.69 0.60 0.64 0.58 0.55 7 1.01 0.82 1.22 0.78 2.20 0.90 1.75 0.92 1.53 0.87 1.06 0.93 1.06 0.94 1.14 0.81 0.58 0.87 8 0.29 0.72 0.25 0.74 0.42 0.64 0.51 0.54 0.30 0.82 0.35 0.55 0.39 0.46 0.36 0.55 0.35 0.74 9 0.57 0.37 0.98 0.69 0.87 0.58 1.28 0.73 1.13 0.65 1.24 0.63 0.84 0.81 1.41 0.79 0.87 0.84 10 0.56 0.80 0.53 0.79 0.67 0.82 0.54 0.86 0.72 0.83 0.89 0.80 0.70 0.67 0.62 0.90 0.54 0.79 Mean 0.47 0.5S 0.55 0.63 0.71 0.61 0.75 0.70 0.72 0.72 0.67 0.68 0.66 0.70 0.70 0.71 0.59 0.68 SD 0.25 0.22 0.34 0.15 0.57 0.18 0.43 0.17 0.41 0.15 0.31 0.16 0.20 0.15 0.34 0.13 0.17 0.14 Table 6.1: HVR results during the SDIH protocol. SD- standard deviation. HVR values are expressed in l i t resmin\" 1 %Sa02' 1 Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8 Day 14 Subject HVR R2 HVR R2 HVR R2 HVR R2 HVR R2 HVR R2 HVR R2 HVR R2 HVR R2 1 0.261 0.461 0.484 0.634 0.455 0.508 0.807 0.545 0.488 0.703 0.778 0.749 0.824 0.592 0.734 0.661 0.651 0.473 2 0.414 0.748 0.298 0.513 0.408 0.716 0.485 0.697 0.477 0.814 0.477 0.793 1.111 0.637 0.694 0.884 0.580 .0.861 3 0.576 0.774 0.674 0.615 0.768 0.785 0.771 0.471 0.704 0.448 0.826 0.539 0.504 0.784 0.599 0.745 0.652 0.536 4 0.212 0.504 0.579 0.884 0.469 0.668 0.456 0.342 0.619 0.785 0.996 0.817 0.656 0.634 1.001 0.823 0.541 0.678 5 0.391 0.508 0.846 0.463 1.036 0.644 1.065 0.669 0.577 0.350 0.719 0.578 0.722 0.649 0.936 0.658 0.778 0.566 6 0.327 0.839 0.796 0.398 0.417 0.470 0.551 0.577 0.740 0.471 0.520 0.660 0.835 0.603 0.696 0.632 0.650 0.532 7 0.875 0.633 0.954 0.842 1.409 0.873 1.222 0.807 1.081 0.948 1.500 0.856 0.981 0.775 1.704 0.851 1.594 0.826 8 0.334 0.452 0.450 0.519 0.414 0.571 0.387 0.496 0.499 0.504 0.457 0.553 0.414 0.665 0.261 0.623 0.295 0.628 9 0.844 0.883 0.782 0.737 0.802 0.784 0.622 0.839 0.649 0.694 0.750 0.704 0.754 0.650 0.814 0.767 0.500 0.658 10 0.470 0.821 0.634 0.803 0.414 0.750 1.039 0.751 0.791 0.796 0.708 0.928 0.578 0.854 0.416 0.766 0.391 0.744 Mean 0.470 0.662 0.650 0.641 0.659 0.677 0.741 0.619 0.662 0.651 0.773 0.718 0.738 0.684 0.785 0.741 0.663 0.650 SD 0.229 0.170 0.202 0.169 0.343 0.130 0.289 0.160 0.183 0.196 0.306 0.134 0.213 0.088 0.391 0.094 0.356 0.129 able 6.2: HVR results during the LDIH protocol. SD- standard deviation. HVR values are expressed in litresmin T o S a C V 1 SDIH Subject Pre- Post-7 days Post-1 1.57 2.63 2.64 2 3.26 3.27 2.41 3 2.49 2.59 2.77 4 4.34 7.52 5.78 5 2.67 3.06 3.78 6 1.40 1.28 1.80 7 5.86 3.97 5.08 8 4.93 4.59 5.22 9 3.27 4.32 3.00 10 2.07 5.23 3.68 Mean 3.19 3.85 3.62 Standard Deviation 1.47 1.73 1.34 Table 6.3: HCVR results during the LDIH and SDIH protocols. LDIH Subject Pre- Post-7 days Post-1 2.46 2.70 1.47 2 2.18 4.79 2.70 3 2.86 .2.57 3.21 4 1.05 3.34 4.12 5 3.95 6.29 6.17 6 2.86 2.63 2.36 7 3.37 5.77 4.73 8 4.43 4.77 5.94 9 2.07 2.32 2.52 10 3.13 5.69 6.92 Mean 2.84 4.09 4.01 Standard Deviation 0.97 1.54 1.86 HCVR values are expressed in litresmin~1 0/ommHg -1 SDIH Threshold Sensitivit y Subject Pre- Post-7 days Post- Pre- Post-7 days Post-1 44.12 42.20 42.66 2.48 1.56 3.49 2 45.23 42.59 42.72 3.06 4.17 3.30 3 44.22 41.53 47.16 2.61 1.73 2.32 4 47.30 42.43 43.15 4.68 4.10 4.40 5 45.11 41.93 44.86 3.71 2.91 3.38 6 48.92 45.78 48.89 1.72 1.64 2.31 7 45.76 45.22 48.56 2.82 3.14 4.54 8 43.44 42.24 43.66 5.21 4.25 4.82 9 44.26 43.13 44.03 2.49 2.78 1.91\" 10 49.61 45.61 46.56 4.29 3.43 2.69 Mean 45.80 43.27 45.23 3.31 2.97 3.32 Standard Deviation 2.12 1.63 2.39 1.12 1.05 1.02 LDIH Threshold Sensitivity Subject Pre- Post-7 days Post- Pre- Post-7 days Post-1 47.91 41.84 43.02 2.31 2.48 3.02 2 47.15 41.64 43.35 4.28 6.59 4.85 3 44.46 43.05 43.05 2.05 1.78 2.37 4 49.07 47.55 48.45 3.84 3.29 4.86 5 44.11 43.06 44.05 3.50 4.34 4.09 6 46.81 46.70 47.60 3.38 2.81 2.68 7 45.21 43.37 45.98 4.27 2.12 2:81 8 42.06 42.58 42.97 5.75 3.67 3.91 9 43.75 44.02 42.33 1.98 2.16 1.94 10 49.31 45.41 46.22 4.15 3.07 5.10 Table 6.4: Hypoxic modified rebreathing method results during the LDIH and SDIH protocols. Threshold units mmHg. Sensitivity values are expressed in litresmin'1%mmHg\"1 Mean 45.98 43.92 44.70 3.55 3.23 3.56 Standard Deviation 2.43 2.01 2.18 1.18 1.41 1.14 SDIH Threshold Sensitivity Subject Pre- Post-7 days Post- Pre- Post-7 days Post-1 39.73 37.86 38.75 4.70 5.01 4.54 2 40.00 37.96 41.35 4.37 5.82 6.40 3 40.54 40.94 42.25 4.94 5.19 5.68 4 44.16 38.02 41.40 5.00 4.80 5.75 5 37.75 39.33 39.54 4.17 4.60 4.85 6 46.58 41.77 41.77 2.60 2.80 3.90 7 44.35 40.30 42.93 4.40 6.55 7.46 8 36.29 37.85 37.64 7.56 7.51 6.11 9 40.71 38.93 39.83 5.40 5.48 3.80 10 43.82 41.15 42.34 4.93 3.29 8.98 Table 6.5: Hyperoxic modified rebrea LDIH Threshold Mean 41.39 39.41 40.78 4.81 5.11 5.75 Standard Deviation 3.24 1.52 1.74 1.23 1.39 1.61 Sensitivity Subject Pre- Post-7 days Post- Pre- Post-7 days Post-1 39.86 38.32 39.15 3.80 5.72 4.45 2 39.63 39.64 39.39 10.71 7.58 7.37 3 40.69 38.48 38.97 3.89 3.13 4.48 4 43.15 40.98 40.31 4.43 4.12 4.44 5 38.61 36.59 37.66 6.58 4.69 4.16 6 40.43 38.61 43.15 4.48 4.24 5.43 7 42.86 39.93 42.73 7.98 6.34 5.57 8 36.87 36.06 37.45 6.58 5.23 9.24 9 39.64 39.52 39.39 3.35 3.61 3.35 10 43.64 41.27 41.97 4.44 5.51 3.96 Mean 40.54 38.94 40.02 5.62 5.02 5.25 Standard Deviation 2.14 1.70 2.00 2.33 1.34 1.79 hing method results during the LDIH and SDIH protocols Threshold units mmHg. Sensitivity values are expressed in litresmin\" 1%mmHg -1 Mean Minute Ventilation Pre-IH Mean Minute Ventilation Post-IH SDIH Normox c Hypoxic Normoxic Hypoxic Subject Low Moderate Low Moderate Low Moderate Low Moderate 1 53.1 77.8 58.0 116.4 48.5 79.5 57.1 96.4 2 39.5 64.4 48.3 41.8 69.4 45.1 3 39.2 70.1 47.2 96.7 41.4 66.7 49.6 90.1 4 37.2 60.7 44.8 83.0 37.4 69.2 46.1 89.7 5 42.1 72.0 46.0 89.2 40.9 75.6 49.5 95.0 6 23.8 48.5 28.3 59.3 23.8 44.6 23.0 50.6 7 40.8 77.9 46.4 90.0 39.7 78.3 48.5 100.3 8 47.3 103.1 57.7 113.5 45.8 85.9 56.6 114.0 9 52.7 87.5 62.4 104.9 53.4 80.0 63.7 100.9 10 38.0 59.0 49.3 86.0 41.2 67.2 50.2 92.6 Mean 41.4 72.1 48.8 93.2 41.4 71.6 48.9 92.2 Standard Deviation 8.5 15.6 9.4 17.4 7.8 11.4 10.7 17.3 Table 6.6: Submaximal minute ventilation values during exercise before and after SDIH. Values are expressed in litresmin\" 1 to Mean Minute Ventilation Pre-IH Mean Minute Ventilation Post-IH LDIH Normoxi c Hypoxic Normox c Hypoxic Subject Low Moderate Low Moderate Low Moderate Low Moderate 1 54.1 78.8 60.0 119.5 44.5 78.8 51.9 98.8 2 35.1 60.7 42.9 44.3 66.9 47.1 3 36.8 59.0 38.2 83.9 41.8 65.1 45.2 90.8 4 42.5 70.0 51.3 106.6 36.9 64.1 47.9 81.9 5 38.7 70.2 41.5 76.2 41.1 66.6 45.8 84.4 6 22.9 42.6 24.9 52.6 22.0 45.6 25.0 56.6 7 38.6 77.8 47.5 100.2 43.6 82.2 49.4 103.0 8 46.9 80.5 50.8 100.5 47.5 81.2 52.1 99.3 9 48.2 80.5 54.7 95.8 49.5 77.9 57.8 96.7 10 39.9 65.8 51.4 89.3 40.4 72.8 50.8 93.1 Mean 40.4 68.6 46.3 91.6 41.2 70.1 47.3 89.4 Standard Deviation 8.5 12.1 9.9 19.4 7.6 11.0 8.7 14.1 Table 6.7: Submaximal minute ventilation values during exercise before and after LDIH. litresmin\"1 Values are expressed in SDIH Subject Pre- Post- Delta 1 83.9 89.0 5.1 2 90.9 92.6 1.7 3 85.0 87.3 2.2 4 85.0 85.6 0.6 5 81.5 86.5 5.0 6 86.2 90.6 4.4 7 86.2 87.7 1.5 8 84.7 87.5 2.8 9 82.4 86.3 3.9 10 83.1 82.4 -0.6 Mean 84.9 87.6 2.7 Standard Deviation 2.6 2.8 1.9 LDIH Subject Pre- Post- Delta 1 86.9 84.5 -2.4 2 90.2 90.2 0.0 3 84.3 86.0 1.7 4 80.4 84.8 4.4 5 86.4 87.7 1.3 6 86.8 86.9 0.1 7 87.8 86.6 -1.2 8 86.4 87.7 1.3 9 89.2 86.8 -2.4 10 82.8 83.6 0.8 Mean 86.1 86.5 0.4 Standard Deviation 2.9 1.9 2.0 Table 6.8: Submaximal saturation values during hypoxic exercise before and expressed in % S a 0 2 after intermittent hypoxia. Values are 0 \\ Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta Subject Pre-SD H 1 50.0 42.7 7.3 51.6 38.8 12.8 66.7 61.5 5.2 78.2 62.9 15.3 2 39.2 34.6 4.6 40.5 28.7 11.9 62.5 57.9 4.6 72.7 56.5 16.1 3 39.4 30.1 9.4 39.8 32.5 7.2 72.5 54.2 18.3 69.6 58.4 11.2 4 37.0 30.8 6.2 40.0 32.2 7.8 64.8 48.0 16.8 60.3 47.3 13.0 5 42.2 34.9 7.3 41.1 37.8 3.3 65.4 51.6 13.8 77.2 67.7 9.5 6 23.0 22.9 0.1 24.7 23.6 1.0 46.3 41.8 4.4 52.6 45.4 7.2 7 43.1 35.3 7.8 39.9 33.8 6.1 78.5 64.4 14.0 81.1 67.0 14.1 8 37.1 36.6 0.6 50.8 42.9 8.0 91.8 78.0 13.9 111.7 94.2 17.5 9 53.9 40.7 13.3 53.7 44.9 8.9 85.2 77.1 8.1 90.2 79.2 11.0 10 33.4 33.5 -0.1 39.2 38.0 1.2 53.2 49.9 3.3 59.3 57.2 2.1 Mean 39.8 34.2 5.6 42.1 35.3 6.8 68.7 58.4 10.2 75.3 63.6 11.7 SD 8.6 5.6 4.4 8.4 6.4 4.0 13.9 12.0 5.7 17.1 14.6 4.6 Post-SDIH 1 52.3 38.4 13.9 47.8 38.8 9.1 78.8 61.6 17.2 83.1 68.0 15.1 2 42.0 34.3 7.7 42.0 40.0 2.0 70.9 60.6 10.3 3 39.6 34.4 5.2 40.3 38.5 1.8 62.4 51.2 11.2 69.9 59.0 10.9 4 35.5 31.0 4.5 37.8 36.5 1.3 67.7 51.8 15.8 71.6 55.2 16.4 5 42.9 33.9 8.9 42.3 36.0 6.3 79.7 66.4 13.3 77.5 68.4 9.1 6 22.6 20.2 2.4 22.6 20.2 2.4 44.2 32.9 11.3 46.4 41.2 5.2 7 41.3 36.7 4.6 38.1 23.8 14.4 79.0 60.4 18.6 83.0 61.1 21.9 8 42.9 36.2 6.7 46.5 43.0 3.5 79.5 70.2 9.3 87.5 80.0 7.5 9 62.6 45.5 17.2 49.3 42.0 7.3 80.0 62.5 17.5 78.1 72.5 5.6 10 40.9 36.7 4.2 37.4 37.2 0.2 69.4 58.1 11.3 67.7 57.3 10.4 Mean 42.3 34.7 7.5 40.4 35.6 4.8 71.2 57.6 13.6 73.9 62.5 11.3 SD 10.3 6.4 4.7 7.6 7.6 4.4 11.3 10.4 3.4 12.2 11.3 5.5 Table 6.9: Hyperoxic Test ventilation values during normoxic exercise before and after SDIH. 3bMA = Three-breath moving average. Pre = mean ventilation for the 30 seconds prior to the challenge. Values are expressed in litresmin\" 1 Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta Subject Pre-LD IH 1 55.3 40.3 15.0 52.0 48.0 4.0 74.7 58.1 16.7 83.5 61.7 21.8 2 36.2 26.7 9.5 31.8 28.0 3.8 63.3 52.6 10.7 60.1 53.9 6.3 3 33.2 33.3 0.0 39.0 32.7 6.3 59.4 50.8 8.6 62.5 50.3 12.2 4 41.1 29.1 12.0 44.1 30.4 13.6 68.6 62.6 6.0 75.2 63.4 11.8 5 40.3 35.2 5.1 37.0 35.3 1.7 70.8 53.0 17.8 75.7 55.5 20.3 6 22.6 20.6 2.1 21.5 18.1 3.4 42.9 39.4 3.4 42.1 37.9 4.3 7 37.5 31.5 6.0 40.5 32.1 8.4 68.9 64.5 4.4 84.6 64.8 19.9 8 49.1 38.2 10.9 48.5 42.5 6.0 76.8 68.6 8.2 82.8 73.8 9.0 9 48.0 36.0 12.0 47.1 39.1 8.0 79.7 68.0 11.7 85.2 73.0 12.2 10 41.3 34.0 7.4 41.0 36.0 5.0 65.9 62.1 3.7 66.7 62.3 4.5 Mean 40.5 32.5 8.0 40.3 34.2 6.0 67.1 58.0 9.1 71.9 59.6 12.2 SD 9.1 5.8 4.8 8.8 8.2 3.4 10.5 9.1 5.1 14.0 10.8 6.5 Post-LDIH 1 50.4 36.9 13.4 44.7 37.3 7.4 79.4 59.6 19.8 80.1 58.1 21.9 2 43.4 37.7 5.7 41.6 30.4 11.2 65.3 56.9 8.4 70.5 51.1 19.5 3 40.7 35.5 5.2 42.0 40.4 1.6 59.3 56.0 3.3 67.5 60.6 7.0 4 33.4 27.8 5.5 36.0 33.4 2.6 62.4 46.8 15.6 65.2 55.1 10.1 5 42.0 37.7 4.3 39.5 36.0 3.5 74.5 63.0 11.5 73.1 63.8 9.3 6 22.0 17.5 4.5 21.2 18.7 2.5 42.7 38.9 3.8 45.8 42.0 3.8 7 43.0 33.0 10.0 45.0 34.8 10.1 72.1 64.3 7.8 83.8 74.7 9.2 8 52.1 39.8 12.3 47.4 40.5 6.9 76.8 67.5 9.3 83.8 60.8 23.0 9 53.0 35.0 18.0 49.9 44.2 5.7 74.0 66.7 7.3 79.0 73.7 5.3 10 39.6 28.8 10.8 40.9 39.4 1.5 73.2 58.8 14.4 74.7 53.2 21.5 Mean 41.9 33.0 9.0 40.8 35.5 5.3 68.0 57.8 10.1 72.3 59.3 13.1 SD 9.3 6.7 4.7 8.0 7.1 3.5 11.0 9.0 5.3 11.3 10.0 7.5 Table 6.10: Hyperoxic Test ventilation values during normoxic exercise before and after LDIH. 3bMA = Three-breath moving average. Pre = mean ventilation for the 30 seconds prior to the challenge. Values are expressed in litresmin -1 Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta Subject Pre-SD H 1 55.2 59.3 4.1 55.6 59.5 3.9 81.8 91.8 10.0 84.6 92.1 7.5 2 38.7 56.5 17.8 39.6 55.7 16.1 61.6 76.2 14.6 61.0 80.0 19.0 3 37.9 43.4 5.5 39.7 43.8 4.1 66.5 83.2 16.7 71.6 82.8 11.2 4 34.7 45.3 10.7 37.0 44.8 7.8 57.6 70.5 12.9 60.1 76.0 15.9 5 40.6 53.8 13.2 44.7 54.9 10.2 70.3 80.5 10.2 75.2 91.1 16.0 6 24.0 32.1 8.1 23.8 31.8 8.0 47.1 55.2 8.1 48.0 60.5 12.5 7 39.3 47.7 8.4 40.9 48.9 8.0 73.2 87.4 14.3 78.8 91.3 12.5 8 49.3 59.1 9.8 51.8 65.2 13.4 99.8 116.7 16.9 108.9 122.6 13.6 9 50.5 53.6 3.1 52.4 61.3 8.9 80.3 97.5 17.2 94.4 124.0 29.6 10 39.2 43.4 4.2 40.2 47.3 7.1 60.2 63.6 3.4 63.1 72.2 9.1 Mean 40.9 49.4 8.5 42.6 51.3 8.8 69.8 82.3 12.4 74.6 89.2 14.7 SD 8.9 8.6 4.6 9.2 10.0 3.8 14.9 17.6 4.5 18.1 20.4 6.2 Post-SDIH 1 44.9 58.6 13.6 48.8 58.2 9.4 77.9 91.1 13.2 78.2 95.0 16.8 2 42.1 47.8 5.7 41.1 59.8 18.7 67.8 80.1 12.3 3 42.0 47.2 5.2 43.5 51.6 8.1 66.3 84.1 17.8 68.2 80.2 11.9 4 38.0 53.9 15.8 38.2 53.1 14.9 68.4 88.8 20.4 69.2 93.6 24.4 5 38.0 45.3 7.3 40.4 47.3 6.9 67.5 83.0 15.5 77.6 86.3 8.6 6 26.8 27.9 1.1 23.0 38.6 15.7 42.0 48.2 6.2 46.0 50.7 4.7 7 41.0 53.7 12.7 38.2 54.5 16.3 72.5 93.5 21.0 78.8 108.6 29.8 8 45.9 66.4 20.6 48.0 63.0 15.0 85.0 95.9 10.9 91.5 105.7 14.1 9 53.8 64.1 10.3 47.9 61.3 13.4 76.2 90.0 13.8 85.8 97.3 11.5 10 40.5 45.7 5.1 46.1 51.5 5.4 62.7 69.0 6.3 68.9 72.8 3.9 Mean 41.3 51.1 9.8 41.5 53.9 12.4 68.6 82.4 13.7 73.8 87.8 14.0 SD 6.9 11.1 5.9 7.7 7.3 4.5 11.4 14.3 5.1 13.1 18.0 8.6 Table 6.11: Hypercapnic Test ventilation values during normoxic exercise before and after SDIH. 3bMA = Three-breath moving average. Pre = mean ventilation for the 30 seconds prior to the challenge. Values are expressed in litresmin\" 1 Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta S u b j e c t P r e - L D I H 1 57.2 66.1 8.9 52.0 64.3 12.3 76.2 97.7 21.5 81.0 93.7 12.7 2 35.8 43.6 7.8 36.6 44.0 7.4 58.0 61.8 3.8 61.5 68.1 6.6 3 34.6 46.0 11.4 40.4 51.8 11.3 56.2 66.6 10.4 57.9 72.6 14.7 4 44.0 49.9 5.9 40.7 51.1 10.4 68.7 96.3 27.5 67.5 93.9 26.3 5 39.6 45.4 5.8 37.7 42.3 4.6 64.0 72.3 8.3 70.4 82.8 12.4 6 24.7 34.8 10.1 22.9 27.1 4.2 41.0 50.9 9.9 44.6 58.1 13.5 7 39.1 41.6 2.5 37.1 55.9 18.9 75.6 88.5 12.9 82.2 97.8 15.7 8 44.7 51.5 6.8 45.0 59.3 14.2 79.7 86.7 7.0 82.7 94.9 12.2 9 47.6 58.2 10.6 50.1 62.8 12.7 75.4 82.1 6.7 81.7 103.3 21.6 10 35.5 39.7 4.3 41.9 47.4 5.5 63.5 65.5 2.0 67.0 72.0 5.0 Mean 40.3 47.7 7.4 40.4 50.6 10.2 65.8 76.8 11.0 69.6 83.7 14.1 SD 8.8 9.2 2.9 8.1 11.1 4.7 11.9 15.7 7.9 12.7 15.2 6.3 P o s t - L D I H 1 38.1 53.1 14.9 44.7 57.1 12.3 74.3 84.0 9.7 81.5 96.7 15.2 2 49.4 51.2 1.8 42.9 51.4 8.5 64.9 80.3 15.4 66.7 81.7 14.9 3 41.1 47.9 6.8 43.6 50.6 7.0 64.0 75.9 11.9 69.5 80.7 11.2 4 39.3 46.7 7.5 39.0 46.3 7.3 65.2 80.0 14.8 63.4 84.7 21.3 5 43.8 49.0 5.2 39.1 45.0 5.8 58.4 64.3 5.9 60.3 67.8 7.5 6 21.8 25.7 3.9 22.9 26.8 3.9 46.6 62.3 15.7 47.4 57.7 10.2 7 41.9 54.8 12.9 44.4 58.6 14.2 89.7 116.9 27.2 83.1 114.9 31.8 8 45.3 55.9 10.5 45.0 59.9 14.9 81.5 98.1 16.6 82.7 98.8 16.1 9 45.0 53.7 8.7 50.3 58.3 8.0 70.8 75.7 4.9 88.0 101.2 13.2 10 39.7 45.5 5.8 41.4 47.9 6.5 67.3 81.3 14.0 76.2 76.7 0.5 Mean 40.5 48.3 7.8 41.3 50.2 8.8 68.3 81.9 13.6 71.9 86.1 14.2 SD 7.4 8.7 4.0 7.2 9.9 3.7 11.9 15.9 6.3 12.7 17.0 8.3 Table 6.12: Hypercapnic Test ventilation values during normoxic exercise before and after LDIH. 3bMA = Three-breath moving average. Pre = mean ventilation for the 30 seconds prior to the challenge. Values are expressed in litresmin\" 1 Pre 3bMA Delta Pre 3bMA Delta Pre | 3bMA Delta Pre 3bMA | Delta Subject Pre-SDIH 1 57.5 38.0 19.5 54.9 37.9 17.0 101.7 55.1 46.6 104.1 68.3 35.9 2 47.7 29.4 18.2 47.4 30.7 16.7 50.9 37.0 13.9 3 44.6 30.5 14.1 48.8 35.5 13.2 104.1 72.9 31.2 107.7 77.2 30.5 4 43.5 24.3 19.2 45.7 26.7 18.9 78.7 50.9 27.9 89.5 55.4 34.1 5 44.7 37.0 7.7 46.6 38.6 8.0 82.5 59.8 22.7 89.8 70.3 19.6 6 28.9 16.8 12.1 28.1 22.2 6.0 57.6 46.4 11.2 60.3 43.4 16.9 7 47.0 32.4 14.6 42.9 35.3 7.6 90.6 65.8 24.8 89.4 66.5 22.9 8 55.5 41.9 13.7 59.0 44.0 15.0 86.5 86.5 0.0 123.8 98.6 25.2 9 58.4 33.4 25.0 62.1 36.6 25.5 105.5 70.8 34.6 106.9 73.3 33.6 10 47.0 25.9 21.1 53.8 22.9 30.9 82.4 48.3 34.1 92.3 61.2 31.1 Mean 47.5 31.0 16.5 48.9 33.0 15.9 84.0 59.4 24.7 96.0 68.2 27.7 SD 8.6 7.4 5.0 9.6 7.2 7.9 18.4 14.8 13.5 17.7 15.3 6.9 Post-SDIH 1 58.1 43.9 14.2 56.8 39.9 16.9 98.7 66.9 31.8 99.5 74.4 25.0 2 46.3 21.3 24.9 42.6 31.6 11.0 3 49.6 26.1 23.6 51.3 39.2 12.1 83.8 55.5 28.3 89.5 63.9 25.6 4 45.1 23.9 21.1 46.6 27.3 19.3 87.3 63.5 23.8 94.6 64.0 30.6 5 50.1 39.8 10.3 51.8 41.3 10.5 97.8 78.9 19.0 99.9 79.2 20.8 6 21.8 15.2 6.6 23.9 18.2 5.8 51.3 34.8 16.4 55.5 37.9 17.6 7 47.9 33.0 14.9 49.2 33.0 16.2 99.1 69.4 29.7 105.0 74.2 30.8 8 55.1 37.9 17.2 58.3 37.7 20.6 102.8 81.2 21.6 120.0 94.1 25.9 9 61.9 32.7 29.2 66.4 36.9 29.5 99.7 58.2 41.5 98.2 69.0 29.2 10 51.4 33.5 17.8 49.4 25.2 24.3 93.0 49.0 44.0 93.1 64.2 28.9 Mean 48.7 30.7 18.0 49.6 33.0 16.6 90.4 61.9 28.5 95.0 69.0 26.1 SD 10.8 9.0 6.9 11.2 7.5 7.1 15.9 14.6 9.5 17.2 15.1 4.5 Table 6.13: Hyperoxic Test ventilation values during hypoxic exercise before and after SDIH. 3bMA = Three-breath moving average. Pre = mean ventilation for the 30 seconds prior to the challenge. Values are expressed in litresmin\" 1 Pre 3bMA | Delta Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta S u b j e c t P r e - L D I H 1 57.5 38.7 18.8 59.5 47.5 12.0 97.3 76.2 21.2 128.3 106.5 21.8 2 43.8 27.7 16.1 42.2 29.7 12.6 73.1 46.4 26.7 72.4 48.2 24.2 3 37.9 26.8 11.2 38.8 31.1 7.7 90.7 55.5 35.2 90.0 65.7 24.3 4 49.0 25.0 24.0 57.0 31.6 25.4 103.4 64.6 38.8 109.5 76.6 32.9 5 40.8 37.0 3.8 42.1 36.3 5.8 74.5 52.9 21.5 78.5 64.6 13.9 6 23.6 14.1 9.5 26.6 20.4 6.2 55.4 36.5 19.0 54.0 40.5 13.5 7 44.8 37.7 7.2 51.6 33.7 17.8 90.5 79.3 11.3 105.0 81.5 23.5 8 50.1 33.5 16.5 50.5 41.1 9.5 92.7 67.4 25.4 107.4 81.0 26.5 9 55.9 37.2 18.8 57.4 33.6 23.7 92.8 64.1 28.7 99.7 80.7 19.0 10 50.1 32.8 17.4 51.4 41.0 10.4 89.4 64.8 24.7 90.1 51.8 38.3 Mean 45.4 31.0 14.3 47.7 34.6 13.1 86.0 60.8 25.2 93.5 69.7 23.8 SD 9.8 7.7 6.2 10.2 7.5 7.0 14.2 13.1 7.9 21.3 19.6 7.7 P o s t - L D I H 1 50.5 38.6 11.9 52.1 37.3 14.8 93.5 70.6 22.9 99.5 74.7 24.8 2 47.4 34.1 13.3 46.2 32.2 14.1 3 43.4 35.4 8.0 48.7 31.0 17.8 88.3 59.8 28.4 99.8 58.8 41.0 4 47.9 21.2 26.6 46.7 26.1 20.5 84.7 38.1 46.6 81.4 35.8 45.6 5 46.0 37.4 8.5 47.6 38.6 9.0 88.2 62.4 25.8 95.6 78.0 17.5 6 23.6 19.8 3.8 25.0 15.5 9.5 53.7 34.1 19.6 56.4 37.5 18.9 7 51.0 39.2 11.8 48.9 31.9 16.9 88.2 71.5 16.7 104.9 95.6 9.3 8 51.8 35.7 16.1 51.3 32.1 19.2 91.3 70.4 20.9 100.1 78.6 21.4 9 54.4 28.6 25.9 58.2 40.5 17.7 90.6 60.1 30.5 100.1 68.6 31.6 10 50.1 32.5 17.5 50.6 30.7 19.9 98.1 54.9 43.2 104.0 80.8 23.2 Mean 46.6 32.2 14.3 47.5 31.6 16.0 86.3 58.0 28.3 93.5 67.6 25.9 SD 8.7 6.9 7.4 8.6 7.1 4.1 12.8 13.7 10.4 15.5 20.1 11.6 Table 6.14: Hyperoxic Test ventilation values during hypoxic exercise before and after LDIH. 3bMA = Three-breath moving average. Pre = mean ventilation for the 30 seconds prior to the challenge. Values are expressed in litresmin\" 1 to Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta Pre 3bMA Delta Subject Pre-SDIH 1 59.7 66.3 6.6 60.1 66.1 6.1 128.3 135.0 6.6 131.3 145.8 14.4 2 47.1 74.3 27.2 51.0 73.7 22.7 78.9 97.6 18.7 3 46.5 57.8 11.3 48.9 64.1 15.3 83.4 103.5 20.1 91.6 108.5 16.9 4 42.3 54.8 12.5 47.8 68.2 20.4 79.3 94.3 15.0 84.5 97.6 13.1 5 44.4 52.3 7.9 48.3 53.7 5.4 86.5 105.1 18.6 98.1 101.0 3.0 6 28.7 37.6 8.9 27.5 41.6 14.1 57.9 61.9 4.0 61.6 68.8 7.2 7 49.3 55.2 5.8 46.3 54.8 8.5 84.7 97.7 13.0 95.2 101.1 5.8 8 58.3 79.3 21.0 57.9 80.1 22.2 123.3 135.7 12.4 120.1 135.3 15.2 9 66.1 83.3 17.2 63.0 71.2 8.2 99.4 121.0 21.6 107.7 134.8 27.1 10 45.7 51.9 6.2 50.7 58.7 7.9 78.9 97.3 18.4 90.6 98.1 7.6 Mean 48.8 61.3 12.5 50.1 63.2 13.1 90.1 104.9 14.8 97.9 110.1 12.3 SD 10.5 14.2 7.2 9.8 11.3 6.8 21.5 21.7 5.9 20.3 24.2 7.3 Post-S 3IH 1 55.0 67.6 12.6 58.5 76.6 18.2 94.0 118.6 24.6 93.4 109.6 16.2 2 44.8 64.7 19.9 46.8 56.6 9.8 3 46.6 58.7 12.2 50.8 60.1 9.3 92.0 114.8 22.7 95.1 130.2 35.1 4 44.6 75.1 30.5 48.2 71.2 22.9 85.5 110.3 24.8 91.2 106.6 15.4 5 47.4 54.8 7.4 48.7 53.7 5.0 85.4 104.3 18.9 96.7 103.0 6.2 6 21.9 32.6 10.7 24.6 30.5 5.9 46.7 63.9 17.3 48.7 51.8 3.1 7 47.0 60.2 13.3 49.9 55.4 5.5 91.8 110.6 18.9 105.3 124.1 18.8 8 55.5 84.0 28.5 57.2 78.4 21.2 113.6 131.4 17.8 119.5 140.2 20.6 9 60.8 75.3 14.6 65.6 72.5 6.9 100.7 110.7 10.0 105.0 124.1 19.1 10 51.4 55.8 4.4 48.7 57.0 8.3 92.2 95.6 3.4 92.3 105.9 13.6 Mean 47.5 62.9 15.4 49.9 61.2 11.3 89.1 106.7 17.6 94.1 110.6 16.5 SD 10.5 14.3 8.5 10.7 14.3 6.8 18.1 18.8 7.0 19.3 25.4 9.1 Table 6.15: Hypercapnic Test ventila ion values during hypoxic exercise before and after SDIH. 3bMA = Three-breath moving average. Pre = mean ventilation for the 30 seconds prior to the challenge. Values are expressed in litresmin\" 1 Pre 3bMA Delta Pre 3bMA Delta | Pre 3bMA Delta | Pre 3bMA Delta Subject Pre-LD H 1 60.1 85.5 25.4 62.9 74.1 11.2 113.0 131.5 18.5 139.4 164.4 24.9 2 42.9 55.0 12.2 42.8 48.8 6.1 65.8 83.1 17.2 70.3 83.8 13.5 3 34.4 51.6 17.2 41.6 52.2 10.6 73.0 98.3 25.2 81.8 102.7 20.9 4 47.6 60.9 13.3 51.7 69.5 17.8 102.1 120.4 18.3 111.3 122.1 10.8 5 40.6 44.2 3.6 42.6 51.1 8.5 68.8 99.3 30.5 83.1 89.5 6.4 6 24.3 38.8 14.5 25.0 29.1 4.1 49.2 66.2 16.9 51.5 69.8 18.3 7 48.1 66.9 18.7 45.5 61.1 15.6 98.8 113.4 14.7 106.4 128.3 21.9 8 51.6 69.8 18.2 51.1 71.2 20.1 98.8 112.7 13.9 103.0 125.0 22.0 9 52.8 59.2 6.4 52.5 63.7 11.2 91.0 107.2 16.2 99.7 110.6 11.0 10 53.9 57.1 3.2 50.0 64.3 14.3 85.4 94.9 9.5 92.1 107.9 15.8 Mean 45.6 58.9 13.3 46.6 58.5 11.9 84.6 102.7 18.1 93.9 110.4 16.5 SD 10.5 13.3 7.2 9.9 13.5 5.1 19.8 18.8 5.9 24.2 26.8 6.0 Post-LDIH 1 51.8 56.8 5.0 53.2 58.8 5.6 92.6 110.7 18.1 109.5 122.0 12.5 2 45.1 46.7 1.6 49.7 66.3 16.6 3 42.9 65.8 22.9 45.8 66.9 21.1 81.5 97.3 15.8 93.6 111.2 17.7 4 47.5 58.8 11.3 49.5 58.1 8.6 78.1 100.6 22.5 83.6 96.9 13.4 5 43.5 53.0 9.5 46.1 51.4 5.3 73.8 89.4 15.6 80.1 90.4 10.3 6 25.0 33.5 8.6 26.3 32.9 6.6 58.4 63.3 4.9 57.8 68.6 10.8 7 52.0 61.7 9.7 45.6 66.9 21.3 112.6 126.0 13.5 106.3 144.8 38.5 8 52.1 73.8 21.7 53.2 70.8 17.6 97.8 111.8 13.9 108.1 122.6 14.5 9 57.0 63.1 6.0 61.7 69.2 7.5 98.4 110.4 12.1 97.6 113.3 15.7 10 51.8 68.8 17.0 50.7 56.9 6.2 81.5 94.2 12.7 89.0 101.7 12.7 Mean 46.9 58.2 11.3 48.2 59.8 11.7 86.1 100.4 14.3 91.7 107.9 16.2 SD 8.9 11.6 7.1 9.0 11.3 6.7 16.0 17.8 4.8 16.6 21.9 8.7 Table 6.16: Hypercapnic Test ventilation values during hypoxic exercise before and after LDIH. 3bMA = Three-breath moving average. Pre = mean ventilation for the 30 seconds prior to the challenge. Values are expressed in litresmin\" 1 Subject SDIH Protocol Day 1 SDIH Protocol Day 8 Ramp Time (s) Peak V02 Peak Ve Ramp Time (s) Peak V02 Peak Ve 1 9 3.06 122.3 64 2.92 131.9 2 0 0 3 0 106.5 150 103.3 4 134 83.3 62 96.1 5 205 2.87 103.3 166 2.84 94.4 6 220 84.0 217 95.8 7 50 174 8 130 2.43 141.4 165 2.65 166.6 9 210 3.81 131.8 330 4.30 174.7 10 160 3.23 111.7 154 3.28 117.8 Mean 111.8 3.1 110.5 148.2 3.2 122.6 Standard Deviation 89.8 0.5 20.9 91.6 0.7 32.4 „ W I I _ _ . w . w . « w and after SDIH. Ventilation and oxygen consumption values are expressed in litresmin\" 1 Subject LDIH Protocol Day 1 LDIH Protocol Day ( iRamp Time (s) Peak V02 Peak Ve Ramp Time (S) Peak V02 Peak Ve 1 60 3.26 132.6 142 3.07 97.2 2 30 0 N/A 3 142 111.9 150 102.3 4 190 136.6 143 89.9 5 216 2.60 97.3 232 2.61 110.5 6 188 89.2 176 88.5 7 148 155 8 180 2.86 149.3 225 3.60 154.8 9 244 3.44 116.2 310 3.35 122.0 10 217 3.24 118.3 241 3.29 125.1 Mean 1 6 1 . 5 3 . 1 1 1 8 . 9 1 7 7 . 4 3 . 2 1 1 1 . 3 Standard Deviation 6 9 . 0 0 . 3 2 0 . 1 8 3 . 0 0 . 4 2 2 . 2 Table 6.18: Peak Ramp time, oxygen consumption V 0 2 , and ventilation during a graded exercise test in hypoxia before and after LDIH. Ventilation and oxygen consumption values are expressed in litresmin\"1 <3\\ "@en ; edm:hasType "Thesis/Dissertation"@en ; vivo:dateIssued "2006-11"@en ; edm:isShownAt "10.14288/1.0077025"@en ; dcterms:language "eng"@en ; ns0:degreeDiscipline "Human Kinetics"@en ; edm:provider "Vancouver : University of British Columbia Library"@en ; dcterms:publisher "University of British Columbia"@en ; dcterms:rights "For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use."@en ; ns0:scholarLevel "Graduate"@en ; dcterms:title "Intermittent hypoxia and the chemoreflex control of breathing"@en ; dcterms:type "Text"@en ; ns0:identifierURI "http://hdl.handle.net/2429/18434"@en .