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Li SN, Peeling P, Scott BR, Peiffer JJ, Shaykevich A, Girard O. Recovery following exercise-induced fatigue: Influence of a single heart rate clamped cycling session under systemic hypoxia. J Sports Sci 2024; 42:350-357. [PMID: 38502604 DOI: 10.1080/02640414.2024.2330816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/08/2024] [Indexed: 03/21/2024]
Abstract
We investigated whether a single heart rate clamped cycling session under systemic hypoxia affects the recovery of physical and psycho-physiological responses from residual fatigue compared to normoxia. On separate occasions, twelve trained males performed a 3-d acute training camp scenario. On days 1 and 3, participants cycled for 60 min at a constant heart rate (80% of ventilatory threshold). On day 2, fatigue was induced through a simulated team game circuit (STGC), followed by a 60-min intervention of either: (1) heart rate clamped cycling in normoxia; (2) heart rate clamped cycling in hypoxia (simulated altitude ~ 3500 m); or (3) no cycling. Countermovement jump height and leg stiffness were assessed before and after every session. Perceptual fatigue was evaluated daily. Compared to baseline, jump height decreased at all timepoints following the STGC (all p < 0.05). Leg stiffness and cycling power output only decreased immediately following the STGC, with a 48% further decrease in cycling power output in hypoxia compared to normoxia (p < 0.05). Perceived fatigue, decreased sleep quality, and increased muscle soreness responses occurred on day 3 (p < 0.05). A single heart rate-clamped cycling session in hypoxia reduced mechanical output without affecting recovery of physical performance and perceptual measures from residual fatigue induced through team sport activity.
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Affiliation(s)
- Siu Nam Li
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Perth, WA, Australia
| | - Peter Peeling
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Perth, WA, Australia
- Department of Sport Science, Western Australian Institute of Sport, Perth, WA, Australia
| | - Brendan R Scott
- Murdoch Applied Sport Science Laboratory, Discipline of Exercise Science, Murdoch University, Perth, WA, Australia
- Centre for Healthy Ageing, Murdoch University, Perth, WA, Australia
| | - Jeremiah J Peiffer
- Murdoch Applied Sport Science Laboratory, Discipline of Exercise Science, Murdoch University, Perth, WA, Australia
- Centre for Healthy Ageing, Murdoch University, Perth, WA, Australia
| | - Alex Shaykevich
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Perth, WA, Australia
- Perron Institute for Neurological and Translational Science, Perth, WA, Australia
| | - Olivier Girard
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Perth, WA, Australia
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Li SN, Peeling P, Scott BR, Peiffer JJ, Shaykevich A, Girard O. Maintenance of internal load despite a stepwise reduction in external load during moderate intensity heart rate clamped cycling with acute graded normobaric hypoxia in males. J Sci Med Sport 2023; 26:628-635. [PMID: 37852804 DOI: 10.1016/j.jsams.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 10/20/2023]
Abstract
OBJECTIVES To investigate the acute effects of graded hypoxia on external and internal loads during 60 min of endurance cycling at a clamped heart rate. DESIGN Repeated measures. METHODS On separate visits, 16 trained males cycled for 60 min at a clamped heart rate corresponding to 80 % of their first ventilatory threshold at sea-level and 2500 m, 3000 m, 3500 m and 4000 m simulated altitudes (inspired oxygen fractions of 20.9 %, 15.4 %, 14.5 %, 13.6 % and 12.7 %, respectively). Markers of external (power output) and internal (blood lactate concentration, tissue saturation index, cardio-respiratory and perceptual responses) loads were measured every 15 min during cycling. Neuromuscular function of knee extensors was characterised pre- and post-exercise. RESULTS Compared to sea-level (101 ± 22 W), there was a stepwise reduction in power output with increasing hypoxia severity (-17.9 ± 8.9 %, -27.1 ± 10.7 %, -34.2 ± 12.0 % and - 44.6 ± 15.1 % at 2500 m, 3000 m, 3500 m, and 4000 m, respectively, all p < 0.05). Blood lactate and tissue saturation index were not different across hypoxia severities, and perceptual responses were exacerbated at 4000 m only, with increased breathing difficulty. Knee extensor torque decreased post-exercise (-14.5 ± 9.0 %, p < 0.05), independent of condition. CONCLUSIONS Increasing hypoxia severity reduces cycling power output and arterial oxygen saturation in a stepwise fashion without affecting exercise responses between sea-level and simulated altitudes up to 3500 m despite breathing difficulty being elevated at 4000 m.
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Affiliation(s)
- Siu Nam Li
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Australia.
| | - Peter Peeling
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Australia; Department of Sport Science, Western Australian Institute of Sport, Australia
| | - Brendan R Scott
- Murdoch Applied Sport Science Laboratory, Discipline of Exercise Science, Murdoch University, Australia; Centre for Healthy Ageing, Murdoch University, Australia
| | - Jeremiah J Peiffer
- Murdoch Applied Sport Science Laboratory, Discipline of Exercise Science, Murdoch University, Australia; Centre for Healthy Ageing, Murdoch University, Australia
| | - Alex Shaykevich
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Australia; Perron Institute for Neurological and Translational Science, Australia
| | - Olivier Girard
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Australia.
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Yu Q, Kong Z, Zou L, Chapman R, Shi Q, Nie J. Comparative efficacy of various hypoxic training paradigms on maximal oxygen consumption: A systematic review and network meta-analysis. J Exerc Sci Fit 2023; 21:366-375. [PMID: 37854170 PMCID: PMC10580050 DOI: 10.1016/j.jesf.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 09/09/2023] [Accepted: 09/16/2023] [Indexed: 10/20/2023] Open
Abstract
Background Enhancement in maximal oxygen consumption (VO2max) induced by hypoxic training is important for both athletes and non-athletes. However, the lack of comparison of multiple paradigms and the exploration of related modulating factors leads to the inability to recommend the optimal regimen in different situations. This study aimed to investigate the efficacy of seven common hypoxic training paradigms on VO2max and associated moderators. Methods Electronic (i.e., five databases) and manual searches were performed, and 42 studies involving 1246 healthy adults were included. Pairwise meta-analyses were conducted to compare different hypoxic training paradigms and hypoxic training and control conditions. The Bayesian network meta-analysis model was applied to calculate the standardised mean differences (SMDs) of pre-post VO2max alteration among hypoxic training paradigms in overall, athlete, and non-athlete populations, while meta-regression analyses were employed to explore the relationships between covariates and SMDs. Results All seven hypoxic training paradigms were effective to varying degrees, with SMDs ranging from 1.45 to 7.10. Intermittent hypoxia interval training (IHIT) had the highest probability of being the most efficient hypoxic training paradigm in the overall population and athlete subgroup (42%, 44%), whereas intermittent hypoxic training (IHT) was the most promising hypoxic training paradigm among non-athletes (66%). Meta-regression analysis revealed that saturation hours (coefficient, 0.004; P = 0.038; 95% CI [0.0002, 0.0085]) accounted for variations of VO2max improvement induced by IHT. Conclusion Efficient hypoxic training paradigms for VO2max gains differed between athletes and non-athletes, with IHIT ranking best for athletes and IHT for non-athletes. The practicability of saturation hours is confirmed with respect to dose-response issues in the future hypoxic training and associated scientific research. Registration This study was registered in the PROSPERO international prospective register of systematic reviews (CRD42022333548).
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Affiliation(s)
- Qian Yu
- Faculty of Education, University of Macau, Macao, China
| | - Zhaowei Kong
- Faculty of Education, University of Macau, Macao, China
| | - Liye Zou
- Exercise Psychophysiology Laboratory, Institute of KEEP Collaborative Innovation, School of Psychology, Shenzhen University, Shenzhen, 518060, China
| | - Robert Chapman
- Department of Kinesiology, School of Public Health, Indiana University, Bloomington, IN, USA
| | - Qingde Shi
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao, China
| | - Jinlei Nie
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao, China
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Burtscher J, Hohenauer E, Burtscher M, Millet GP, Egg M. Environmental and behavioral regulation of HIF-mitochondria crosstalk. Free Radic Biol Med 2023; 206:63-73. [PMID: 37385566 DOI: 10.1016/j.freeradbiomed.2023.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/05/2023] [Accepted: 06/19/2023] [Indexed: 07/01/2023]
Abstract
Reduced oxygen availability (hypoxia) can lead to cell and organ damage. Therefore, aerobic species depend on efficient mechanisms to counteract detrimental consequences of hypoxia. Hypoxia inducible factors (HIFs) and mitochondria are integral components of the cellular response to hypoxia and coordinate both distinct and highly intertwined adaptations. This leads to reduced dependence on oxygen, improved oxygen supply, maintained energy provision by metabolic remodeling and tapping into alternative pathways and increased resilience to hypoxic injuries. On one hand, many pathologies are associated with hypoxia and hypoxia can drive disease progression, for example in many cancer and neurological diseases. But on the other hand, controlled induction of hypoxia responses via HIFs and mitochondria can elicit profound health benefits and increase resilience. To tackle pathological hypoxia conditions or to apply health-promoting hypoxia exposures efficiently, cellular and systemic responses to hypoxia need to be well understood. Here we first summarize the well-established link between HIFs and mitochondria in orchestrating hypoxia-induced adaptations and then outline major environmental and behavioral modulators of their interaction that remain poorly understood.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.
| | - Erich Hohenauer
- Rehabilitation and Exercise Science Laboratory (RES Lab), Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland; International University of Applied Sciences THIM, Landquart, Switzerland; Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland; Department of Movement and Sport Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Margit Egg
- Institute of Zoology, University of Innsbruck, Innsbruck, Austria
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Li SN, Ihsan M, Shaykevich A, Girard O. Exercise responses to heart rate clamped cycling with graded blood flow restriction. J Sci Med Sport 2023; 26:434-439. [PMID: 37394395 DOI: 10.1016/j.jsams.2023.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/26/2023] [Accepted: 06/15/2023] [Indexed: 07/04/2023]
Abstract
OBJECTIVES To quantify the acute effects of graded blood flow restriction on the interaction between changes in mechanical output, muscle oxygenation trends and perceptual responses to heart rate clamped cycling. DESIGN Repeated measures. METHODS Twenty-five adults (21 men) performed six, 6-min cycling bouts (24 min of recovery) at a clamped heart rate corresponding to their first ventilatory threshold at 0 % (unrestricted), 15 %, 30 %, 45 %, 60 % and 75 % of arterial occlusion pressure with the cuffs inflated bilaterally from the fourth to the sixth minute. Power output, arterial oxygen saturation (pulse oximetry) and vastus lateralis muscle oxygenation (near-infrared spectroscopy) were monitored during the final 3 min of pedalling, whilst perceptual responses (modified Borg CR10 scales) were obtained immediately after exercise. RESULTS Compared to unrestricted cycling, average power output for minutes 4-6 decreased exponentially for cuff pressures ranging 45-75 % of arterial occlusion pressure (P < 0.001). Peripheral oxygen saturation averaged ∼96 % across all cuff pressures (P = 0.318). Deoxyhemoglobin changes were larger at 45-75 % versus 0 % of arterial occlusion pressure (P < 0.05), whereas higher total haemoglobin values occurred at 60-75 % of arterial occlusion pressure (P < 0.05). Sense of effort, ratings of perceived exertion, pain from cuff pressure, and limb discomfort were exaggerated at 60-75 % versus 0 % of arterial occlusion pressure (P < 0.001). CONCLUSIONS Blood flow restriction of at least 45 % of arterial occlusion pressure is required to reduce mechanical output during heart rate clamped cycling at the first ventilatory threshold. Whilst power decreases non-linearly above this pressure threshold, higher occlusion levels ranging 60-75 % of arterial occlusion pressure also accentuate muscle deoxygenation and exercise-related sensations.
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Affiliation(s)
- Siu Nam Li
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Australia
| | - Mohammed Ihsan
- Human Potential Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Republic of Singapore; Department of Rehabilitation, Faculty of Medicine, Chiang Mai University, Thailand
| | - Alex Shaykevich
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Australia; Perron Institute for Neurological and Translational Science, Perth, WA, Australia
| | - Olivier Girard
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Australia.
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Camacho-Cardenosa A, Burtscher J, Burtscher M, Camacho-Cardenosa M. Editorial: Hypoxia as a therapeutic tool in search of healthy aging. Front Physiol 2023; 13:1112129. [PMID: 36714319 PMCID: PMC9877216 DOI: 10.3389/fphys.2022.1112129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 12/28/2022] [Indexed: 01/15/2023] Open
Affiliation(s)
- Alba Camacho-Cardenosa
- PROFITH (PROmoting FITness and Health through Physical Activity) Research Group, Sport and Health University Research Institute (iMUDS), Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Martin Burtscher
- Institute of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Marta Camacho-Cardenosa
- Clinical Management Unit of Endocrinology and Nutrition - GC17, Maimónides Biomedical Research Institute of Cordoba (IMIBIC), Reina Sofía University Hospital, Córdoba, Spain,*Correspondence: Marta Camacho-Cardenosa,
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Li SN, Peeling P, Scott BR, Peiffer JJ, Shaykevich A, Girard O. Automatic heart rate clamp: A practical tool to control internal and external training loads during aerobic exercise. Front Physiol 2023; 14:1170105. [PMID: 37089418 PMCID: PMC10119421 DOI: 10.3389/fphys.2023.1170105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 03/29/2023] [Indexed: 04/25/2023] Open
Affiliation(s)
- Siu Nam Li
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Perth, WA, Australia
- *Correspondence: Siu Nam Li, ; Olivier Girard,
| | - Peter Peeling
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Perth, WA, Australia
- Department of Sport Science, Western Australian Institute of Sport, Mount Claremont, WA, Australia
| | - Brendan R. Scott
- Murdoch Applied Sport Science Laboratory, Discipline of Exercise Science, Murdoch University, Perth, WA, Australia
- Centre for Healthy Ageing, Murdoch University, Perth, WA, Australia
| | - Jeremiah J. Peiffer
- Murdoch Applied Sport Science Laboratory, Discipline of Exercise Science, Murdoch University, Perth, WA, Australia
- Centre for Healthy Ageing, Murdoch University, Perth, WA, Australia
| | - Alex Shaykevich
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Perth, WA, Australia
- Perron Institute for Neurological and Translational Science, Perth, WA, Australia
| | - Olivier Girard
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Perth, WA, Australia
- *Correspondence: Siu Nam Li, ; Olivier Girard,
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Costa GP, Camacho-Cardenosa A, Brazo-Sayavera J, Viliod MCDL, Camacho-Cardenosa M, Foresti YF, de Carvalho CD, Merellano-Navarro E, Papoti M, Trapé ÁA. Effectiveness, implementation, and monitoring variables of intermittent hypoxic bicycle training in patients recovered from COVID-19: The AEROBICOVID study. Front Physiol 2022; 13:977519. [PMID: 36406995 PMCID: PMC9667939 DOI: 10.3389/fphys.2022.977519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 10/17/2022] [Indexed: 11/29/2022] Open
Abstract
Hypoxic exposure is safely associated with exercise for many pathological conditions, providing additional effects on health outcomes. COVID-19 is a new disease, so the physiological repercussions caused by exercise in affected patients and the safety of exposure to hypoxia in these conditions are still unknown. Due to the effects of the disease on the respiratory system and following the sequence of AEROBICOVID research work, this study aimed to evaluate the effectiveness, tolerance and acute safety of 24 bicycle training sessions performed under intermittent hypoxic conditions through analysis of peripheral oxyhemoglobin saturation (SpO2), heart rate (HR), rate of perceived exertion (RPE), blood lactate concentration ([La-]) and symptoms of acute mountain sickness in patients recovered from COVID-19. Participants were allocated to three training groups: the normoxia group (GN) remained in normoxia (inspired fraction of O2 (FiO2) of ∼20.9%, a city with 526 m altitude) for the entire session; the recovery hypoxia group (GHR) was exposed to hypoxia (FiO2 ∼13.5%, corresponding to 3,000 m altitude) all the time except during the effort; the hypoxia group (GH) trained in hypoxia (FiO2 ∼13.5%) throughout the session. The altitude simulation effectively reduced SpO2 mean with significant differences between groups GN, GHR, and GH, being 96.9(1.6), 95.1(3.1), and 87.7(6.5), respectively. Additionally, the proposed exercise and hypoxic stimulus was well-tolerated, since 93% of participants showed no or moderate acute mountain sickness symptoms; maintained nearly 80% of sets at target heart rate; and most frequently reporting session intensity as an RPE of "3" (moderate). The internal load calculation, analyzed through training impulse (TRIMP), calculated using HR [TRIMPHR = HR * training volume (min)] and RPE [TRIMPRPE = RPE * training volume (min)], showed no significant difference between groups. The current strategy effectively promoted the altitude simulation and monitoring variables, being well-tolerated and safely acute exposure, as the low Lake Louise scores and the stable HR, SpO2, and RPE values showed during the sessions.
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Affiliation(s)
- Gabriel Peinado Costa
- School of Physical Education and Sport of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Alba Camacho-Cardenosa
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Javier Brazo-Sayavera
- Department of Sports and Computer Science, Universidad Pablo de Olavide, Seville, Spain,Polo de Desarrollo Universitario EFISAL, Centro Universitario Regional Noreste, Universidad de la República, Rivera, Uruguay
| | | | - Marta Camacho-Cardenosa
- Clinical Management Unit of Endocrinology and Nutrition - GC17, Maimónides Biomedical Research Institute of Cordoba (IMIBIC), Reina Sofía University Hospital, Córdoba, Spain
| | - Yan Figueiredo Foresti
- School of Physical Education and Sport of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil
| | | | - Eugenio Merellano-Navarro
- Departamento de Ciencias de la Actividad Física, Facultad de Ciencias de la Educación, Universidad Católica del Maule, Talca, Chile
| | - Marcelo Papoti
- School of Physical Education and Sport of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil,Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Átila Alexandre Trapé
- School of Physical Education and Sport of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil,*Correspondence: Átila Alexandre Trapé,
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Li Tee CC, Chong MC, Sundar V, Chok CL, Md Razali MR, Yeo WK, Girard O. Influence of exercise intensity and hypoxic exposure on physiological, perceptual and biomechanical responses to treadmill running. Eur J Sport Sci 2022:1-10. [PMID: 35912915 DOI: 10.1080/17461391.2022.2109066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractAcute physiological, perceptual and biomechanical consequences of manipulating both exercise intensity and hypoxic exposure during treadmill running were determined. On separate days, eleven trained individuals ran for 45 s (separated by 135 s of rest) on an instrumented treadmill at seven running speeds (8, 10, 12, 14, 16, 18 and 20 km.h-1) in normoxia (NM, FiO2 = 20.9%), moderate hypoxia (MH, FiO2 = 16.1%), high hypoxia (HH, FiO2 = 14.1%) and severe hypoxia (SH, FiO2 = 13.0%). Running mechanics were collected over 20 consecutive steps (i.e., after running ∼25 s), with concurrent assessment of physiological (heart rate and arterial oxygen saturation) and perceptual (overall perceived discomfort, difficulty breathing and leg discomfort) responses. Two-way repeated-measures ANOVA (seven speeds × four conditions) were used. There was a speed × condition interaction for heart rate (p = 0.045, ηp2 = 0.22), with lower values in NM, MH and HH compared to SH at 8 km.h-1 (125 ± 12, 125 ± 11, 128 ± 12 vs 132 ± 10 b.min-1). Overall perceived discomfort (8 and 16 km.h-1; p = 0.019 and p = 0.007, ηp2 =0.21, respectively) and perceived difficulty breathing (all speeds; p = 0.023, ηp2 =0.37) were greater in SH compared to MH, whereas leg discomfort was not influenced by hypoxic exposure. Minimal difference was observed in the twelve kinetics/kinematics variables with hypoxia (p > 0.122; ηp2 = 0.19). Running at slower speeds in combination with severe hypoxia elevates physiological and perceptual responses without a corresponding increase in ground reaction forces.
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Affiliation(s)
- Chris Chow Li Tee
- Division of Research and Innovation, National Sports Institute of Malaysia, Kuala Lumpur, Malaysia.,School of Health Sciences, Swinburne University of Technology, Melbourne, Australia
| | - Mee Chee Chong
- School of Health Sciences, Swinburne University of Technology, Melbourne, Australia
| | - Viswanath Sundar
- Division of Sports Performance, National Sports Institute of Malaysia, Kuala Lumpur, Malaysia
| | - Chuen Leang Chok
- Division of Sports Performance, National Sports Institute of Malaysia, Kuala Lumpur, Malaysia
| | - Mohd Rizal Md Razali
- Division of Research and Innovation, National Sports Institute of Malaysia, Kuala Lumpur, Malaysia
| | - Wee Kian Yeo
- Division of Research and Innovation, National Sports Institute of Malaysia, Kuala Lumpur, Malaysia
| | - Olivier Girard
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
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Camacho-Cardenosa A, Camacho-Cardenosa M, Tomas-Carus P, Timón R, Olcina G, Burtscher M. Acute physiological response to a normobaric hypoxic exposure: sex differences. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2022; 66:1495-1504. [PMID: 35585281 DOI: 10.1007/s00484-022-02298-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
Although preliminary studies suggested sex-related differences in physiological responses to altitude/hypoxia, controlled studies from standardised exposures to normobaric hypoxia are largely lacking. Hence, the goals of this study were to provide information on cardiorespiratory responses to a 7-h normobaric hypoxia exposure and to explore potential differences between men and women. In this crossover study, a total of 15 men and 14 women were subjected to a 7-h exposure in normoxia (FiO2: 21%) and normobaric hypoxia (FiO2: 15%). Values of peripheral oxygen saturation, heart rate, systolic and diastolic blood pressure and respiratory gases were recorded every hour (8 time points), and oxygen saturation every 30 min (15 time points). Compared to normoxia, exposure to hypoxia significantly increased minute ventilation from baseline to hour 7 in males (+ 71%) and females (+ 40%), significantly greater in men (p < 0.05). A steeper decrease in peripheral oxygen saturation until 2.5 h in hypoxia was seen in females compared to males (p < 0.05). In conclusion, the ventilatory response to hypoxia was more pronounced in men compared to women. Moreover, during the first hours in hypoxia, peripheral oxygen saturation dropped more markedly in women than in men, likely due an initially lower and/or less efficient ventilatory response to moderate hypoxia. Those findings should be considered when performing interventions for therapy or prevention in normobaric hypoxia. Nevertheless, further large-scaled and well-controlled studies are needed.
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Affiliation(s)
| | - Marta Camacho-Cardenosa
- Faculty of Sport Sciences, University of Extremadura, Cáceres, Spain.
- Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Av. Menéndez Pidal, Edificio IMIBIC, s/n, 14004, Córdoba, Córdoba, Spain.
| | - Pablo Tomas-Carus
- Departamento de Desporto e Saúde, Escola de Saúde e Desenvolvimento Humano, Universidade de Évora, Évora, Portugal
- Comprehensive Health Research Centre (CHRC), University of Évora, Évora, Portugal
| | - Rafael Timón
- Faculty of Sport Sciences, University of Extremadura, Cáceres, Spain
| | - Guillermo Olcina
- Faculty of Sport Sciences, University of Extremadura, Cáceres, Spain
| | - Martin Burtscher
- Sport Science, Medical Section, University of Innsbruck, Innsbruck, Austria
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