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Feng X, Chen Y, Yan T, Lu H, Wang C, Zhao L. Effects of various living-low and training-high modes with distinct training prescriptions on sea-level performance: A network meta-analysis. PLoS One 2024; 19:e0297007. [PMID: 38635743 PMCID: PMC11025749 DOI: 10.1371/journal.pone.0297007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 12/22/2023] [Indexed: 04/20/2024] Open
Abstract
This study aimed to separately compare and rank the effect of various living-low and training-high (LLTH) modes on aerobic and anaerobic performances in athletes, focusing on training intensity, modality, and volume, through network meta-analysis. We systematically searched PubMed, Web of Science, Embase, EBSCO, and Cochrane from their inception date to June 30, 2023. Based on the hypoxic training modality and the intensity and duration of work intervals, LLTH was divided into intermittent hypoxic exposure, continuous hypoxic training, repeated sprint training in hypoxia (RSH; work interval: 5-10 s and rest interval: approximately 30 s), interval sprint training in hypoxia (ISH; work interval: 15-30 s), short-duration high-intensity interval training (s-IHT; short work interval: 1-2 min), long-duration high-intensity interval training (l-IHT; long work interval: > 5 min), and continuous and interval training under hypoxia. A meta-analysis was conducted to determine the standardized mean differences (SMDs) among the effects of various hypoxic interventions on aerobic and anaerobic performances. From 2,072 originally identified titles, 56 studies were included in the analysis. The pooled data from 53 studies showed that only l-IHT (SMDs: 0.78 [95% credible interval; CrI, 0.52-1.05]) and RSH (SMDs: 0.30 [95% CrI, 0.10-0.50]) compared with normoxic training effectively improved athletes' aerobic performance. Furthermore, the pooled data from 29 studies revealed that active intermittent hypoxic training compared with normoxic training can effectively improve anaerobic performance, with SMDs ranging from 0.97 (95% CrI, 0.12-1.81) for l-IHT to 0.32 (95% CrI, 0.05-0.59) for RSH. When adopting a program for LLTH, sufficient duration and work intensity intervals are key to achieving optimal improvements in athletes' overall performance, regardless of the potential improvement in aerobic or anaerobic performance. Nevertheless, it is essential to acknowledge that this study incorporated merely one study on the improvement of anaerobic performance by l-IHT, undermining the credibility of the results. Accordingly, more related studies are needed in the future to provide evidence-based support. It seems difficult to achieve beneficial adaptive changes in performance with intermittent passive hypoxic exposure and continuous low-intensity hypoxic training.
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Affiliation(s)
- Xinmiao Feng
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Yonghui Chen
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Teishuai Yan
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Hongyuan Lu
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Chuangang Wang
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Linin Zhao
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
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2
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Thompson BP, Doherty CJ, Mann LM, Chang JC, Angus SA, Foster GE, Au JS, Dominelli PB. Supramaximal Testing to Confirm the Achievement of V̇O 2max in Acute Hypoxia. Med Sci Sports Exerc 2024; 56:673-681. [PMID: 37962226 DOI: 10.1249/mss.0000000000003339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
PURPOSE We sought to determine if supramaximal exercise testing confirms the achievement of V̇O 2max in acute hypoxia. We hypothesized that the incremental and supramaximal V̇O 2 will be sufficiently similar in acute hypoxia. METHODS Twenty-one healthy adults (males n = 13, females n = 8) completed incremental and supramaximal exercise tests in normoxia and acute hypoxia (fraction inspired oxygen = 0.14) separated by at least 48 h. Incremental exercise started at 80 and 60 W in normoxia and 40 and 20 W in hypoxia for males and females, respectively, with all increasing by 20 W each minute until volitional exhaustion. After a 20-min postexercise rest period, a supramaximal test at 110% peak power until volitional exhaustion was completed. RESULTS Supramaximal exercise testing yielded a lower V̇O 2 than incremental testing in hypoxia (3.11 ± 0.78 vs 3.21 ± 0.83 L·min -1 , P = 0.001) and normoxia (3.71 ± 0.91 vs 3.80 ± 1.02 L·min -1 , P = 0.01). Incremental and supramaximal V̇O 2 were statistically similar, using investigator-determined equivalence bounds ±150 mL·min -1 , in hypoxia ( P = 0.02, 90% confidence interval [CI] = 0.05-0.14) and normoxia ( P = 0.03, 90% CI = 0.01-0.14). Likewise, using ±2.1 mL·kg -1 ·min -1 bounds, incremental and supramaximal V̇O 2 values were statistically similar in hypoxia ( P = 0.04, 90% CI = 0.70-2.0) and normoxia ( P = 0.04, 90% CI = 0.30-2.0). CONCLUSIONS Despite differences in the oxygen cascade, incremental and supramaximal V̇O 2 values were statistically similar in both hypoxia and normoxia, demonstrating the utility of supramaximal verification of V̇O 2max in the setting of acute hypoxia.
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Affiliation(s)
- Benjamin P Thompson
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, Waterloo, ON, CANADA
| | - Connor J Doherty
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, Waterloo, ON, CANADA
| | - Leah M Mann
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, Waterloo, ON, CANADA
| | - Jou-Chung Chang
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, Waterloo, ON, CANADA
| | - Sarah A Angus
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, Waterloo, ON, CANADA
| | - Glen E Foster
- School of Health and Exercise Sciences, University of British Columbia, Kelowna, BC, CANADA
| | - Jason S Au
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, Waterloo, ON, CANADA
| | - Paolo B Dominelli
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, Waterloo, ON, CANADA
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Burtscher J, Raberin A, Brocherie F, Malatesta D, Manferdelli G, Citherlet T, Krumm B, Bourdillon N, Antero J, Rasica L, Burtscher M, Millet GP. Recommendations for Women in Mountain Sports and Hypoxia Training/Conditioning. Sports Med 2024; 54:795-811. [PMID: 38082199 PMCID: PMC11052836 DOI: 10.1007/s40279-023-01970-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2023] [Indexed: 04/28/2024]
Abstract
The (patho-)physiological responses to hypoxia are highly heterogeneous between individuals. In this review, we focused on the roles of sex differences, which emerge as important factors in the regulation of the body's reaction to hypoxia. Several aspects should be considered for future research on hypoxia-related sex differences, particularly altitude training and clinical applications of hypoxia, as these will affect the selection of the optimal dose regarding safety and efficiency. There are several implications, but there are no practical recommendations if/how women should behave differently from men to optimise the benefits or minimise the risks of these hypoxia-related practices. Here, we evaluate the scarce scientific evidence of distinct (patho)physiological responses and adaptations to high altitude/hypoxia, biomechanical/anatomical differences in uphill/downhill locomotion, which is highly relevant for exercising in mountainous environments, and potentially differential effects of altitude training in women. Based on these factors, we derive sex-specific recommendations for mountain sports and intermittent hypoxia conditioning: (1) Although higher vulnerabilities of women to acute mountain sickness have not been unambiguously shown, sex-dependent physiological reactions to hypoxia may contribute to an increased acute mountain sickness vulnerability in some women. Adequate acclimatisation, slow ascent speed and/or preventive medication (e.g. acetazolamide) are solutions. (2) Targeted training of the respiratory musculature could be a valuable preparation for altitude training in women. (3) Sex hormones influence hypoxia responses and hormonal-cycle and/or menstrual-cycle phases therefore may be factors in acclimatisation to altitude and efficiency of altitude training. As many of the recommendations or observations of the present work remain partly speculative, we join previous calls for further quality research on female athletes in sports to be extended to the field of altitude and hypoxia.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Antoine Raberin
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport, Paris, France
| | - Davide Malatesta
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Giorgio Manferdelli
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Tom Citherlet
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Bastien Krumm
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Nicolas Bourdillon
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Juliana Antero
- Institut de Recherche Bio-Médicale Et d'Épidémiologie du Sport (EA 7329), French Institute of Sport, Paris, France
| | - Letizia Rasica
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland.
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Kayser B, Mariani B. Exceptional Performance in Competitive Ski Mountaineering: An Inertial Sensor Case Study. Front Sports Act Living 2022; 4:854614. [PMID: 35469245 PMCID: PMC9033938 DOI: 10.3389/fspor.2022.854614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Abstract
Organized biannually in the Swiss Alps since 1984, the “Patrouille des Glaciers” (PDG) is one of the most challenging long-distance ski mountaineering (skimo) team competitions in the world. The race begins in Zermatt (1,616 m) and ends in Verbier (1,520 m), covering a total distance of 53 km with a cumulated 4,386 m of ascent and 4,482 m of descent. About 4,800 athletes take part in this competition, in teams of three. We hereby present the performance analysis of the uphill parts of this race of a member (#1) of the winning team in 2018, setting a new race record at 5 h and 35 min, in comparison with two amateur athletes. The athletes were equipped with the Global Navigation Satellite System (GNSS) antenna, a heart rate monitor, and a dedicated multisensor inertial measurement unit (IMU) attached to a ski, which recorded spatial-temporal gait parameters and transition events. The athletes' GNSS and heart rate data were synchronized with the IMU data. Athlete #1 had a baseline VO2 max of 80 ml/min/kg, a maximum heart rate of 205 bpm, weighed 69 kg, and had a body mass index (BMI) of 21.3 kg/m2. During the race, he carried 6 kg of gear and kept his heart rate constant around 85% of max. Spatiotemporal parameters analysis highlighted his ability to sustain higher power, higher pace, and, thus, higher vertical velocity than the other athletes. He made longer steps by gliding longer at each step and performed less kick turns in a shorter time. He spent only a cumulative 5 min and 30 s during skins on and off transitions. Skimo performance, thus, requires a high aerobic power of which a high fraction can be maintained for a prolonged time. Our results further confirm earlier observations that speed of ascent during endurance skimo competitions is a function of body weight and race gear and vertical energy cost of locomotion, with the latter function of climbing gradient. It is also the first study to provide some reference benchmarks for spatiotemporal parameters of elite and amateur skimo athletes during climbing using real-world data.
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Affiliation(s)
- Bengt Kayser
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
- *Correspondence: Bengt Kayser ; orcid.org/0000-0002-9776-7501
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Sousa A, Viana JL, Milheiro J, Reis VM, Millet GP. Dietary Nitrate Supplementation Is Not Helpful for Endurance Performance at Simulated Altitude Even When Combined With Intermittent Normobaric Hypoxic Training. Front Physiol 2022; 13:839996. [PMID: 35360239 PMCID: PMC8964050 DOI: 10.3389/fphys.2022.839996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
IntroductionTraining intensity and nutrition may influence adaptations to training performed in hypoxia and consequently performance outcomes at altitude. This study investigates if performance at simulated altitude is improved to a larger extent when high-intensity interval training is performed in normobaric hypoxia and if this is potentiated when combined with chronic dietary nitrate (NO3−) supplementation.MethodsThirty endurance-trained male participants were allocated to one of three groups: hypoxia (13% FiO2) + NO3−; hypoxia + placebo; and normoxia (20.9% FiO2) + placebo. All performed 12 cycling sessions (eight sessions of 2*6 × 1 min at severe intensity with 1 min recovery and four sessions of 4*6*10 s all-out with 20 s recovery) during a 4-week period (three sessions/week) with supplementation administered 3–2.5 h before each session. An incremental exhaustion test, a severe intensity exercise bout to exhaustion (Tlim) and a 3 min all-out test (3AOT) in hypoxia (FiO2 = 13%) with pulmonary oxygen uptake (V˙O2), V˙O2 kinetics, and changes in vastus lateralis local O2 saturation (SmO2) measured were completed by each participant before and after training.ResultsIn all tests, performance improved to the same extent in hypoxia and normoxia, except for SmO2 after Tlim (p = 0.04, d = 0.82) and 3AOT (p = 0.03, d = 1.43) which were lower in the two hypoxic groups compared with the normoxic one. Dietary NO3− supplementation did not bring any additional benefits.ConclusionPerformance at simulated altitude was not improved to a larger extent when high-intensity interval training was undertaken in normobaric hypoxic conditions, when compared with normoxic training. Additionally, dietary NO3− supplementation was ineffective in further enhancing endurance performance at simulated altitude.
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Affiliation(s)
- Ana Sousa
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), Instituto Universitário da Maia (ISMAI), Maia, Portugal
- *Correspondence: Ana Sousa,
| | - João L. Viana
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), Instituto Universitário da Maia (ISMAI), Maia, Portugal
| | - Jaime Milheiro
- CMEP - Exercise Medical Center & Spa, Porto, Portugal
- Olympic Committee of Portugal, Lisbon, Portugal
| | - Vítor M. Reis
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal
| | - Grégoire P. Millet
- ISSUL, Institute of Sport Sciences and Physical Education (ISSEP), University of Lausanne, Lausanne, Switzerland
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6
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Modelling the relationships between arterial oxygen saturation, exercise intensity and the level of aerobic performance in acute hypoxia. Eur J Appl Physiol 2021; 121:1993-2003. [PMID: 33782716 DOI: 10.1007/s00421-021-04667-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE The aim of this study was to establish a model to estimate the level of arterial oxygen saturation (SpO2) and help determine the appropriate hypoxic dose in humans exercising in acute hypoxia. METHODS SpO2 values were collected in seven untrained (UTS) and seven endurance-trained male subjects (ETS) who performed six cycle incremental and maximal tests at sea level and at simulated altitudes of 1000, 1500, 2500, 3500 and 4500 m. Oxygen uptake was continuously measured and maximal oxygen uptake ([Formula: see text]) was determined in each subject and at each altitude. Intensity was expressed as percentage of [Formula: see text]. RESULTS There were strong non-linear relationships between altitude and SpO2 at low, moderate and high intensity both in ETS and UTS (r = 0.97, p < 0.001). SpO2 was significantly correlated to exercise intensity at sea level and at all simulated altitudes in ETS but only from 2500 m in UTS. There were inverse correlations between SpO2 and sea-level [Formula: see text] at all altitudes, which were stronger from 2500 m and with the increase in exercise intensity. The three-variable model we established predicts (p < 0.001) the SpO2 level of individuals exercising in acute hypoxia based on their sea-level [Formula: see text], the intensity of exercise and the altitude level. CONCLUSION The model demonstrates that the drop of SpO2 during exercise in acute hypoxia is larger with the increase in both sea-level [Formula: see text] and exercise intensity. The model also highlights that the pivotal altitude from which the fall in SpO2 is exacerbated is between 2000 and 2500 m, depending on both sea-level [Formula: see text] and exercise intensity.
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7
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Sotiridis A, Debevec T, Ciuha U, McDonnell AC, Mlinar T, Royal JT, Mekjavic IB. Aerobic but not thermoregulatory gains following a 10-day moderate-intensity training protocol are fitness level dependent: A cross-adaptation perspective. Physiol Rep 2021; 8:e14355. [PMID: 32061183 PMCID: PMC7023889 DOI: 10.14814/phy2.14355] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 10/28/2019] [Indexed: 11/24/2022] Open
Abstract
Moderate‐intensity exercise sessions are incorporated into heat‐acclimation and hypoxic‐training protocols to improve performance in hot and hypoxic environments, respectively. Consequently, a training effect might contribute to aerobic performance gains, at least in less fit participants. To explore the interaction between fitness level and a training stimulus commonly applied during acclimation protocols, we recruited 10 young males of a higher (more fit‐MF, peak aerobic power [VO2peak]: 57.9 [6.2] ml·kg−1·min−1) and 10 of a lower (less fit‐LF, VO2peak: 41.7 [5.0] ml·kg−1·min−1) fitness level. They underwent 10 daily exercise sessions (60 min@50% peak power output [Wpeak]) in thermoneutral conditions. The participants performed exercise testing on a cycle ergometer before and after the training period in normoxic (NOR), hypoxic (13.5% FiO2; HYP), and hot (35°C, 50% RH; HE) conditions in a randomized and counterbalanced order. Each test consisted of two stages; a steady‐state exercise (30 min@40% NOR Wpeak to evaluate thermoregulatory function) followed by incremental exercise to exhaustion. VO2peak increased by 9.2 (8.5)% (p = .024) and 10.2 (15.4)% (p = .037) only in the LF group in NOR and HE, respectively. Wpeak increases were correlated with baseline values in NOR (r = −.58, p = .010) and HYP (r = −.52, p = .018). MF individuals improved gross mechanical efficiency in HYP. Peak sweat rate increased in both groups in HE, whereas MF participants activated the forehead sweating response at lower rectal temperatures post‐training. In conclusion, an increase in VO2peak but not mechanical efficiency seems probable in LF males after a 10‐day moderate‐exercise training protocol.
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Affiliation(s)
- Alexandros Sotiridis
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.,Faculty of Sports, University of Ljubljana, Ljubljana, Slovenia
| | - Urša Ciuha
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Adam C McDonnell
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Tinkara Mlinar
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.,Jozef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Joshua T Royal
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.,Jozef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Igor B Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
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8
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Sumi D, Hayashi N, Yatsutani H, Goto K. Exogenous glucose oxidation during endurance exercise in hypoxia. Physiol Rep 2020; 8:e14457. [PMID: 32652803 PMCID: PMC7354086 DOI: 10.14814/phy2.14457] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/27/2020] [Accepted: 04/30/2020] [Indexed: 12/22/2022] Open
Abstract
Purpose Endurance exercise in hypoxia promotes carbohydrate (CHO) metabolism. However, detailed CHO metabolism remains unclear. The purpose of this study was to evaluate the effects of endurance exercise in moderate hypoxia on exogenous glucose oxidation at the same energy expenditure or relative exercise intensity. Methods Nine active healthy males completed three trials on different days, consisting of 30 min of running at each exercise intensity: (a) exercise at 65% of normoxic maximal oxygen uptake in normoxia [NOR, fraction of inspired oxygen (FiO2) = 20.9%, 10.6 ± 0.3 km/h], (b) exercise at the same relative exercise intensity with NOR in hypoxia (HYPR, FiO2 = 14.5%, 9.4 ± 0.3 km/h), and (c) exercise at the same absolute exercise intensity with NOR in hypoxia (HYPA, FiO2 = 14.5%, 10.6 ± 0.3 km/h). The subjects consumed 113C‐labeled glucose immediately before exercise, and expired gas samples were collected during exercise to determine 13C‐excretion (calculated by 13CO2/12CO2). Results The exercise‐induced increase in blood lactate was significantly augmented in the HYPA than in the NOR and HYPR (p = .001). HYPA involved a significantly higher respiratory exchange ratio (RER) during exercise compared with the other two trials (p < .0001). In contrast, exogenous glucose oxidation (13C‐excretion) during exercise was significantly lower in the HYPA than in the NOR (p = .03). No significant differences were observed in blood lactate elevation, RER, or exogenous glucose oxidation between NOR and HYPR. Conclusion Endurance exercise in moderate hypoxia caused a greater exercise‐induced blood lactate elevation and RER compared with the running exercise at same absolute exercise intensity in normoxia. However, exogenous glucose oxidation (13C‐excretion) during exercise was attenuated compared with the same exercise in normoxia.
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Affiliation(s)
- Daichi Sumi
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan.,Research Fellow of Japan Society for the Promotion of Science, Chiyodaku, Japan
| | - Nanako Hayashi
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Haruka Yatsutani
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Kazushige Goto
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan.,Faculty of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
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9
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da Mota GR, Willis SJ, Sobral NDS, Borrani F, Billaut F, Millet GP. Ischemic Preconditioning Maintains Performance on Two 5-km Time Trials in Hypoxia. Med Sci Sports Exerc 2020; 51:2309-2317. [PMID: 31169794 DOI: 10.1249/mss.0000000000002049] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE The ergogenic effect of ischemic preconditioning (IPC) on endurance exercise performed in hypoxia remains debated and has never been investigated with successive exercise bouts. Therefore, we evaluated if IPC would provide immediate or delayed effects during two 5-km cycling time trials (TT) separated by ~1 h in hypoxia. METHODS In a counterbalanced randomized crossover design, 13 healthy males (27.5 ± 3.6 yr) performed two maximal cycling 5-km TT separated by ~1 h of recovery (TT1 25 min and TT2 2 h post-IPC/SHAM), preceded by IPC (3 × 5 min occlusion 220 mm Hg/reperfusion 0 mm Hg, bilaterally on thighs) or SHAM (20 mm Hg) at normobaric hypoxia (fraction of inspired oxygen [FiO2] of 16%). Performance and physiological (i.e., oxyhemoglobin saturation, heart rate, blood lactate, and vastus lateralis oxygenation) parameters were recorded. RESULTS Time to complete (P = 0.011) 5-km TT and mean power output (P = 0.005) from TT1 to TT2 were worse in SHAM, but not in IPC (P = 0.381/P = 0.360, respectively). There were no differences in time, power output, or physiological variables during the two TT between IPC and SHAM. All muscle oxygenation indices differed (P < 0.001) during the IPC/SHAM with a greater deoxygenation in IPC. During the TT, there was a greater concentration of total hemoglobin in IPC than SHAM (P = 0.047) and greater total hemoglobin in TT1 than TT2. Further, the concentration of oxyhemoglobin was lower during TT2 than TT1 (P = 0.005). CONCLUSION In moderate hypoxia, IPC allowed maintaining a higher blood volume during a subsequent maximal exercise, mitigating the performance decrement between two consecutive cycling TT.
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Affiliation(s)
- Gustavo R da Mota
- Human Performance and Sport Research Group, Department of Sport Sciences, Institute of Health Sciences, Federal University of Triangulo Mineiro, Uberaba, MG, BRAZIL.,Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, SWITZERLAND
| | - Sarah J Willis
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, SWITZERLAND
| | - Nelson Dos Santos Sobral
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, SWITZERLAND
| | - Fabio Borrani
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, SWITZERLAND
| | | | - Grégoire P Millet
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, SWITZERLAND
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10
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Aebi MR, Willis SJ, Girard O, Borrani F, Millet GP. Active Preconditioning With Blood Flow Restriction or/and Systemic Hypoxic Exposure Does Not Improve Repeated Sprint Cycling Performance. Front Physiol 2019; 10:1393. [PMID: 31798461 PMCID: PMC6867998 DOI: 10.3389/fphys.2019.01393] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/28/2019] [Indexed: 11/30/2022] Open
Abstract
Purpose The aim of this study was to evaluate the effects of active preconditioning techniques using blood flow restriction or/and systemic hypoxic exposure on repeated sprint cycling performance and oxygenation responses. Methods Participants were 17 men; 8 were cycle trained (T: 21 ± 6 h/week) and 9 were untrained but physically active (UT). Each participant completed 4 cycles of 5 min stages of cycling at 1.5 W⋅kg–1 in four conditions [Control; IPC (ischemic preconditioning) with partial blood flow restriction (60% of relative total occlusion pressure); HPC (hypoxic preconditioning) in normobaric systemic hypoxia (FIO2 13.6%); and HIPC (hypoxic and ischemic preconditioning combined)]. Following a 40 min rest period, a repeated sprint exercise (RSE: 8 × 10 s sprints; 20 s of recovery) was performed. Near-infrared spectroscopy parameters [for each sprint, change in deoxyhemoglobin (Δ[HHb]), total hemoglobin (Δ[tHb]), and tissue saturation index (ΔTSI%)] were measured. Results Trained participants achieved higher power outputs (+10–16%) than UT in all conditions, yet RSE performance did not differ between active preconditioning techniques in the two groups. All conditions induced similar sprint decrement scores during RSE in both T and UT (16 ± 2 vs. 23 ± 9% in CON; 17 ± 3 vs. 19 ± 6% in IPC; 18 ± 5 vs. 20 ± 10% in HPC; and 17 ± 3 vs. 21 ± 5% in HIPC, for T and UT, respectively). During the sprints, Δ[HHb] was larger after IPC than both HPC and CON in T (p < 0.001). The Δ[tHb] was greater after HPC than all other conditions in T, whereas IPC, HPC, and HIPC induced higher Δ[tHb] than CON in UT. Conclusion None of the active preconditioning methods had an ergogenic effect on repeated sprint cycling performance, despite some specific hemodynamic responses (e.g., greater oxygen extraction and changes in blood volume), which were emphasized in the trained cyclists.
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Affiliation(s)
- Mathias R Aebi
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Aeromedical Center (AeMC), Swiss Air Force, Dübendorf, Switzerland
| | - Sarah J Willis
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Olivier Girard
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Murdoch Applied Sports Science (MASS) Laboratory, Murdoch University, Perth, WA, Australia
| | - Fabio Borrani
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Grégoire P Millet
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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11
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HAILE DIRESIBACHEWW, DURUSSEL JÉRÔME, MEKONEN WONDYEFRAW, ONGARO NEFORD, ANJILA EDWIN, MOOSES MARTIN, DASKALAKI EVANGELIA, MOOSES KERLI, MCCLURE JOHND, SUTEHALL SHAUN, PITSILADIS YANNISP. Effects of EPO on Blood Parameters and Running Performance in Kenyan Athletes. Med Sci Sports Exerc 2019; 51:299-307. [DOI: 10.1249/mss.0000000000001777] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Paradis-Deschênes P, Joanisse DR, Billaut F. Ischemic Preconditioning Improves Time Trial Performance at Moderate Altitude. Med Sci Sports Exerc 2018; 50:533-541. [PMID: 29112625 DOI: 10.1249/mss.0000000000001473] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Endurance athletes often compete and train at altitude where exercise capacity is reduced. Investigating acclimation strategies is therefore critical. Ischemic preconditioning (IPC) can improve endurance performance at sea level through improved O2 delivery and utilization, which could also prove beneficial at altitude. However, data are scarce, and there is no study at altitudes commonly visited by endurance athletes. METHODS In a randomized, crossover study, we investigated performance and physiological responses in 13 male endurance cyclists during four 5-km cycling time trials (TT), preceded by either IPC (3 × 5 min ischemia/5-min reperfusion cycles at 220 mm Hg) or SHAM (20 mm Hg) administered to both thighs, at simulated low (FIO2 0.180, ~1200 m) and moderate (FIO2 0.154, ~2400 m) altitudes. Time to completion, power output, cardiac output (Q˙), arterial O2 saturation (SpO2), quadriceps tissue saturation index (TSI) and RPE were recorded throughout the TT. Differences between IPC and SHAM were analyzed at every altitude using Cohen effect size (ES) and compared with the smallest worthwhile change. RESULTS At low altitude, IPC possibly improved time to complete the TT (-5.2 s, -1.1%; Cohen ES ± 90% confidence limits -0.22, -0.44; 0.01), power output (2.7%; ES 0.21, 0.08; 0.51), and Q˙ (5.0%; ES 0.27, 0.00; 0.54), but did not alter SpO2, muscle TSI, and RPE. At moderate altitude, IPC likely enhanced completion time (-7.3 s; -1.5%; ES -0.38, -0.55; -0.20), and power output in the second half of the TT (4.6%; ES 0.28, -0.15; 0.72), increased SpO2 (1.0%; ES 0.38, -0.05; 0.81), and decreased TSI (-6.5%; ES -0.27, -0.73; 0.20) and RPE (-5.4%, ES -0.27, -0.48; -0.06). CONCLUSIONS Ischemic preconditioning may provide an immediate and effective strategy to defend SpO2 and enhance high-intensity endurance performance at moderate altitude.
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Affiliation(s)
- Pénélope Paradis-Deschênes
- Department of Kinesiology, Laval University, Quebec, QC, CANADA.,Department of Kinesiology, Laval University, Quebec, QC, CANADA
| | - Denis R Joanisse
- Department of Kinesiology, Laval University, Quebec, QC, CANADA.,Department of Kinesiology, Laval University, Quebec, QC, CANADA
| | - François Billaut
- Department of Kinesiology, Laval University, Quebec, QC, CANADA.,Department of Kinesiology, Laval University, Quebec, QC, CANADA.,Department of Kinesiology, Laval University, Quebec, QC, CANADA
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13
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Giampá SQDC, Souza JFTD, Mello MTD, Tufik S, Santos RVTD, Antunes HKM. MAXIMUM EFFORT TRAINING PERFORMED IN HYPOXIA ALTERS THE MOOD PROFILE. REV BRAS MED ESPORTE 2018. [DOI: 10.1590/1517-869220182406133712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT Introduction: Physical exercise at high altitude has become constant. However, the risks associated with this type of exercise represent a major concern, considering the influence of important stressors such as hypoxia and physical exercise on psychobiological and physiological responses. Objective: Analyze the mood state and behavior of physiological variables of volunteers subjected to a progressive loading protocol until they reached maximum volitional exhaustion, both at sea level and at a simulated altitude of 4500 meters. Method: For both conditions studied, the volunteers responded to two instruments that assess mood responses: The Brunel Mood Scale and the Visual Analogue Mood Scale. They also underwent blood sampling to measure blood lactate levels and to evaluate oxygen-hemoglobin saturation. These procedures were performed before, immediately after, and 30 and 60 minutes after the end of the protocol. Results: Hypoxia triggered negative effects on mood responses, especially when compared to sea level conditions. An increase in fatigue level (p=0.02) and mental confusion (p=0.04) was observed immediately after the exercise session, and reduction of vigor (p=0.03) was noted at 30 minutes, accompanied by a reduction in oxygen-hemoglobin saturation immediately after the session and at 30 minutes. There was also an increase in blood lactate levels immediately after the session (p=0.006). Conclusion: The particularities of the hypoxic environment associated with maximum exercise are able to cause a deterioration of mood and physiological responses, which can negatively modulate physical performance. This is a cross-sectional clinical study.
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Affiliation(s)
| | | | | | | | - Ronaldo Vagner Thomatieli dos Santos
- Universidade Federal de São Paulo, Brazil; Laboratório Interdisciplinar em Fisiologia e Exercício, Brazil; Universidade Federal de São Paulo, Brazil
| | - Hanna Karen Moreira Antunes
- Universidade Federal de São Paulo, Brazil; Laboratório Interdisciplinar em Fisiologia e Exercício, Brazil; Universidade Federal de São Paulo, Brazil
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14
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Mourot L, Millet GP. Is Maximal Heart Rate Decrease Similar Between Normobaric Versus Hypobaric Hypoxia in Trained and Untrained Subjects? High Alt Med Biol 2018; 20:94-98. [PMID: 30489174 DOI: 10.1089/ham.2018.0104] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We compared the decrease in maximal heart rate (HRmax) from normoxia to normobaric (NH) and hypobaric (HH) hypoxia, respectively, in trained and untrained subjects (n = 187). HRmax data in normoxia and NH (n = 55) or HH (n = 26) were collected from 81 publications. No study directly compared HRmax in NH and HH. Concomitant arterial oxygen saturation (SaO2) and HRmax data were found in 60 studies. Overall, the results showed that the higher the desaturation, the greater the decrease in HRmax. Since desaturation appeared to be slightly higher during HH versus NH and was higher in trained than in untrained subjects, the decrease in HRmax tended (p = 0.07) to be higher in trained subjects in HH than in NH (e.g., -12.7 bpm vs. -8.6 bpm at 4000 m), whereas in untrained subjects the difference was negligible (-9.9 bpm vs. -8.3 bpm). To conclude, when compared with normoxia, the decrease in HRmax was slightly higher in HH than in NH in trained subjects. However, this result has to be confirmed and from a practical point of view, one may question the significance of this difference as well as the relevance of using different HR values for prescribing training intensity during exercise performed in NH or in HH.
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Affiliation(s)
- Laurent Mourot
- 1 EA 3920 Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation Platform, University of Franche-Comté, Besançon, France.,2 Tomsk Polytechnic University, Tomsk, Russia
| | - Grégoire P Millet
- 3 Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne, Switzerland
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15
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Sumi D, Kojima C, Kasai N, Goto K. The effects of endurance exercise in hypoxia on acid-base balance and potassium kinetics: a randomized crossover design in male endurance athletes. SPORTS MEDICINE - OPEN 2018; 4:45. [PMID: 30317397 PMCID: PMC6186263 DOI: 10.1186/s40798-018-0160-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/04/2018] [Indexed: 11/25/2022]
Abstract
Background Exercise-induced disturbance of acid-base balance and accumulation of extracellular potassium (K+) are suggested to elicit fatigue. Exercise under hypoxic conditions may augment exercise-induced alterations of these two factors compared with exercise under normoxia. In the present study, we investigated acid-base balance and potassium kinetics in response to exercise under moderate hypoxic conditions in endurance athletes. Methods Nine trained middle-to-long distance athletes [maximal oxygen uptake (VO2max) 57.2 ± 1.0 mL/kg/min] completed two different trials on different days, consisting of exercise in moderate hypoxia [fraction of inspired oxygen (FiO2) = 14.5%, H trial] and exercise in normoxia (FiO2 = 20.9%, N trial). They performed interval endurance exercise (8 × 4 min pedaling at 80% of VO2max alternated with 2-min intervals of active rest at 40% of VO2max) under hypoxic or normoxic conditions. Venous blood samples were obtained to determine blood lactate, pH, bicarbonate ion, and K+ concentrations before exercise, during exercise, and after exercise. Results The blood lactate concentrations increased significantly with exercise in both trials. Exercise-induced blood lactate elevations were significantly greater in the N trial than in the H trial at all time points (P = 0.012). Bicarbonate ion concentrations (P = 0.001) and blood pH (P = 0.019) during exercise and post-exercise periods were significantly lower in the N trial than in the H trial. A significantly greater exercise-induced elevation in blood K+ concentration was produced in the N trial than in the H trial during exercise and immediately after exercise (P = 0.03). Conclusions High-intensity interval exercise on a cycle ergometer under moderate hypoxic conditions did not elicit a decrease in blood pH or elevation in K+ levels compared with an equivalent level of exercise under normoxic conditions.
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Affiliation(s)
- Daichi Sumi
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Chihiro Kojima
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Nobukazu Kasai
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Kazushige Goto
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan. .,Faculty of Sports and Health Science, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga, 525-8577, Japan.
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16
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Sumi D, Kojima C, Goto K. Impact of Endurance Exercise in Hypoxia on Muscle Damage, Inflammatory and Performance Responses. J Strength Cond Res 2018; 32:1053-1062. [PMID: 28368957 DOI: 10.1519/jsc.0000000000001911] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Sumi, D, Kojima, C, and Goto, K. Impact of endurance exercise in hypoxia on muscle damage, inflammatory and performance responses. J Strength Cond Res 32(4): 1053-1062, 2018-This study evaluated muscle damage and inflammatory and performance responses after high-intensity endurance exercise in moderate hypoxia among endurance athletes. Nine trained endurance athletes completed 2 different trials on different days: exercise under moderate hypoxia (H trial, FiO2 = 14.5%) and normoxia (N trial, FiO2 = 20.9%). They performed interval exercises (10 × 3-minute running at 95% of V[Combining Dot Above]O2max with 60-second of active rest at 60% of V[Combining Dot Above]O2max) followed by 30-minute of continuous running at 85% of V[Combining Dot Above]O2max under either hypoxic or normoxic conditions. Venous blood samples were collected 4 times: before exercise, 0, 60, and 120-minute after exercise. The time to exhaustion (TTE) during running at 90% of V[Combining Dot Above]O2max was also determined to evaluate endurance capacity 120-minute after the training session. The H trial induced a significantly greater exercise-induced elevation in the blood lactate concentration than did the N trial (p = 0.02), whereas the elevation in the exercise-induced myoglobin concentration (muscle damage marker) was significantly greater in the N trial than in the H trial (p = 0.005). There was no significant difference in plasma interleukin-6 (inflammatory marker) concentration between the H and N trials. The TTE was shorter in the N trial (613 ± 65 seconds) than in the H trial (783 ± 107 seconds, p = 0.02). In conclusion, among endurance athletes, endurance exercise under moderate hypoxic conditions did not facilitate an exercise-induced muscle damage response or cause a further reduction in the endurance capacity compared with equivalent exercise under normoxic conditions.
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Affiliation(s)
- Daichi Sumi
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Chihiro Kojima
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Kazushige Goto
- Graduate School of Sports and Health Science, Ritsumeikan University, Kusatsu, Japan.,Faculty of Sports and Health Science, Ritsumeikan University, Kusatsu, Japan
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17
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Fornasiero A, Savoldelli A, Skafidas S, Stella F, Bortolan L, Boccia G, Zignoli A, Schena F, Mourot L, Pellegrini B. Delayed parasympathetic reactivation and sympathetic withdrawal following maximal cardiopulmonary exercise testing (CPET) in hypoxia. Eur J Appl Physiol 2018; 118:2189-2201. [PMID: 30051338 DOI: 10.1007/s00421-018-3945-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/13/2018] [Indexed: 12/14/2022]
Abstract
PURPOSE This study investigated the effects of acute hypoxic exposure on post-exercise cardiac autonomic modulation following maximal cardiopulmonary exercise testing (CPET). METHODS Thirteen healthy men performed CPET and recovery in normoxia (N) and normobaric hypoxia (H) (FiO2 = 13.4%, ≈ 3500 m). Post-exercise cardiac autonomic modulation was assessed during recovery (300 s) through the analysis of fast-phase and slow-phase heart rate recovery (HRR) and heart rate variability (HRV) indices. RESULTS Both short-term, T30 (mean difference (MD) 60.0 s, 95% CI 18.2-101.8, p = 0.009, ES 1.01), and long-term, HRRt (MD 21.7 s, 95% CI 4.1-39.3, p = 0.020, ES 0.64), time constants of HRR were higher in H. Fast-phase (30 and 60 s) and slow-phase (300 s) HRR indices were reduced in H either when expressed in bpm or in percentage of HRpeak (p < 0.05). Chronotropic reserve recovery was lower in H than in N at 30 s (MD - 3.77%, 95% CI - 7.06 to - 0.49, p = 0.028, ES - 0.80) and at 60 s (MD - 7.23%, 95% CI - 11.45 to - 3.01, p = 0.003, ES - 0.81), but not at 300 s (p = 0.436). Concurrently, Ln-RMSSD was reduced in H at 60 and 90 s (p < 0.01) but not at other time points during recovery (p > 0.05). CONCLUSIONS Affected fast-phase, slow-phase HRR and HRV indices suggested delayed parasympathetic reactivation and sympathetic withdrawal after maximal exercise in hypoxia. However, a similar cardiac autonomic recovery was re-established within 5 min after exercise cessation. These findings have several implications in cardiac autonomic recovery interpretation and in HR assessment in response to high-intensity hypoxic exercise.
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Affiliation(s)
- Alessandro Fornasiero
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy. .,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Aldo Savoldelli
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Spyros Skafidas
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Federico Stella
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Lorenzo Bortolan
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Gennaro Boccia
- NeuroMuscularFunction Research Group, Department of Medical Sciences, School of Exercise and Sport Sciences, University of Turin, Turin, Italy
| | - Andrea Zignoli
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy
| | - Federico Schena
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Laurent Mourot
- Laboratory of Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation Platform (EA 3920), University of Bourgogne Franche-Comté, Besançon, France.,Tomsk Polytechnic University, Tomsk, Russia
| | - Barbara Pellegrini
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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18
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Mourot L. Limitation of Maximal Heart Rate in Hypoxia: Mechanisms and Clinical Importance. Front Physiol 2018; 9:972. [PMID: 30083108 PMCID: PMC6064954 DOI: 10.3389/fphys.2018.00972] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/02/2018] [Indexed: 12/17/2022] Open
Abstract
The use of exercise intervention in hypoxia has grown in popularity amongst patients, with encouraging results compared to similar intervention in normoxia. The prescription of exercise for patients largely rely on heart rate recordings (percentage of maximal heart rate (HRmax) or heart rate reserve). It is known that HRmax decreases with high altitude and the duration of the stay (acclimatization). At an altitude typically chosen for training (2,000-3,500 m) conflicting results have been found. Whether or not this decrease exists or not is of importance since the results of previous studies assessing hypoxic training based on HR may be biased due to improper intensity. By pooling the results of 86 studies, this literature review emphasizes that HRmax decreases progressively with increasing hypoxia. The dose–response is roughly linear and starts at a low altitude, but with large inter-study variabilities. Sex or age does not seem to be a major contributor in the HRmax decline with altitude. Rather, it seems that the greater the reduction in arterial oxygen saturation, the greater the reduction in HRmax, due to an over activity of the parasympathetic nervous system. Only a few studies reported HRmax at sea/low level and altitude with patients. Altogether, due to very different experimental design, it is difficult to draw firm conclusions in these different clinical categories of people. Hence, forthcoming studies in specific groups of patients are required to properly evaluate (1) the HRmax change during acute hypoxia and the contributing factors, and (2) the physiological and clinical effects of exercise training in hypoxia with adequate prescription of exercise training intensity if based on heart rate.
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Affiliation(s)
- Laurent Mourot
- EA 3920 Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation Platform, University of Franche-Comté, Besançon, France.,Tomsk Polytechnic University, Tomsk, Russia
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19
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Saugy JJ, Rupp T, Faiss R, Lamon A, Bourdillon N, Millet GP. Cycling Time Trial Is More Altered in Hypobaric than Normobaric Hypoxia. Med Sci Sports Exerc 2016; 48:680-8. [PMID: 26559447 DOI: 10.1249/mss.0000000000000810] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Slight physiological differences between acute exposure in normobaric hypoxia (NH) and hypobaric hypoxia (HH) have been reported. Taken together, these differences suggest different physiological responses to hypoxic exposure to a simulated altitude (NH) versus a terrestrial altitude (HH). For this purpose, in the present study, we aimed to directly compare the time-trial performance after acute hypoxia exposure (26 h, 3450 min) by the same subjects under three different conditions: NH, HH, and normobaric normoxia (NN). Based on all of the preceding studies examining the differences among these hypoxic conditions, we hypothesized greater performance impairment in HH than in NH. METHODS The experimental design consisted of three sessions: NN (Sion: FiO2, 20.93), NH (Sion, hypoxic room: FiO2, 13.6%; barometric pressure, 716 mm Hg), and HH (Jungfraujoch: FiO2, 20.93; barometric pressure, 481 mm Hg). The performance was evaluated at the end of each session with a cycle time trial of 250 kJ. RESULTS The mean time trial duration in NN was significantly shorter than under the two hypoxic conditions (P < 0.001). In addition, the mean duration in NH was significantly shorter than that in HH (P < 0.01). The mean pulse oxygen saturation during the time trial was significantly lower for HH than for NH (P < 0.05), and it was significantly higher in NN than for the two other sessions (P < 0.001). CONCLUSION As previously suggested, HH seems to be a more stressful stimulus, and NH and HH should not be used interchangeability when endurance performance is the main objective. The principal factor in this performance difference between hypoxic conditions seemed to be the lower peripheral oxygen saturation in HH at rest, as well as during exercise.
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Affiliation(s)
- Jonas J Saugy
- 1ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, SWITZERLAND; 2Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, SWITZERLAND; 3Exercise Physiology Laboratory, Savoie Mont Blanc University, Chambery, FRANCE
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20
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Girard O, Bula S, Faiss R, Brocherie F, Millet GY, Millet GP. Does altitude level of a prior time-trial modify subsequent exercise performance in hypoxia and associated neuromuscular responses? Physiol Rep 2016. [PMCID: PMC4962066 DOI: 10.14814/phy2.12804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We examined the influence of prior time‐trials performed at different altitudes on subsequent exercise in moderate hypoxia and associated cardiometabolic and neuromuscular responses. In normobaric hypoxia (simulated altitude 2000 m; FiO2: 0.163), 10 healthy males performed (1) an incremental test to exhaustion (VO2max_2000) and (2) a test to exhaustion at 80% of the power output associated to VO2max_2000 for a reference time (947 ± 336 sec). Thereafter, two sessions were conducted in a randomized order: a cycle time‐trial corresponding to the reference time (TT1) followed 22 min later (passive rest at 2000 m) by a 6‐min cycle time‐trial (TT2). TT1 was either performed at 2000 or 3500 m (FiO2: 0.135), while TT2 was always performed at 2000 m. As expected, during TT1, the mean power output (247 ± 42 vs. 227 ± 37 W; P < 0.001) was higher at 2000 than 3500 m. During TT2, the mean power output (256 ± 42 vs. 252 ± 36 W) did not differ between conditions. Before and after TT1, maximal isometric voluntary contraction torque in knee extensors (pooled conditions: −7.9 ± 8.4%; P < 0.01), voluntary activation (−4.1 ± 3.1%; P < 0.05), and indices of muscle contractility (peak twitch torque: −39.1 ± 11.9%; doublet torques at 100 Hz: −15.4 ± 8.9%; 10/100 Hz ratio: −25.8 ± 7.7%; all P < 0.001) were equally reduced at 2000 m or 3500 m. Irrespective of the altitude of TT1, neuromuscular function remained similarly depressed after TT1 both before and after TT2 at 2000 m. A prior time‐trial performed at different altitude influenced to the same extent performance and associated cardiometabolic and neuromuscular responses during a subsequent exercise in moderate hypoxia.
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Affiliation(s)
- Olivier Girard
- Department of Physiology; Faculty of Biology and Medicine; ISSUL; Institute of Sport Sciences; University of Lausanne; Lausanne Switzerland
| | - Simone Bula
- Department of Physiology; Faculty of Biology and Medicine; ISSUL; Institute of Sport Sciences; University of Lausanne; Lausanne Switzerland
| | - Raphaël Faiss
- Department of Physiology; Faculty of Biology and Medicine; ISSUL; Institute of Sport Sciences; University of Lausanne; Lausanne Switzerland
| | - Franck Brocherie
- Department of Physiology; Faculty of Biology and Medicine; ISSUL; Institute of Sport Sciences; University of Lausanne; Lausanne Switzerland
| | - Guillaume Y. Millet
- Human Performance Laboratory; Faculty of Kinesiology; University of Calgary; Calgary AB Canada
| | - Grégoire P. Millet
- Department of Physiology; Faculty of Biology and Medicine; ISSUL; Institute of Sport Sciences; University of Lausanne; Lausanne Switzerland
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Gaston AF, Roca E, Doucende G, Hapkova I, Subirats E, Durand F. Réponses physiologiques à l’exercice en altitude modérée : intérêt de la mesure de la SpO2. Sci Sports 2016. [DOI: 10.1016/j.scispo.2015.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wehrlin JP, Marti B, Hallén J. Hemoglobin Mass and Aerobic Performance at Moderate Altitude in Elite Athletes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 903:357-74. [PMID: 27343108 DOI: 10.1007/978-1-4899-7678-9_24] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Fore more than a decade, the live high-train low (LHTL) approach, developed by Levine and Stray-Gundersen, has been widely used by elite endurance athletes. Originally, it was pointed out, that by living at moderate altitude, athletes should benefit from an increased red cell volume (RCV) and hemoglobin mass (Hbmass), while the training at low altitudes should prevent the disadvantage of reduced training intensity at moderate altitude. VO2max is reduced linearly by about 6-8 % per 1000 m increasing altitude in elite athletes from sea level to 3000 m, with corresponding higher relative training intensities for the same absolute work load. With 2 weeks of acclimatization, this initial deficit can be reduced by about one half. It has been debated during the last years whether sea-level training or exposure to moderate altitude increases RCV and Hbmass in elite endurance athletes. Studies which directly measured Hbmass with the optimized CO-rebreathing technique demonstrated that Hbmass in endurance athletes is not influenced by sea-level training. We documented that Hbmass is not increased after 3 years of training in national team cross-country skiers. When athletes are exposed to moderate altitude, new studies support the argument that it is possible to increase Hbmass temporarily by 5-6 %, provided that athletes spend >400 h at altitudes above 2300-2500 m. However, this effect size is smaller than the reported 10-14 % higher Hbmass values of endurance athletes living permanently at 2600 m. It remains to be investigated whether endurance athletes reach these values with a series of LHTL camps.
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Affiliation(s)
- Jon Peter Wehrlin
- Swiss Federal Institute of Sport, Magglingen, Switzerland. .,Norwegian School of Sport Sciences, Oslo, Norway.
| | - Bernard Marti
- Swiss Federal Institute of Sport, Magglingen, Switzerland
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Van Thienen R, Hespel P. Enhanced muscular oxygen extraction in athletes exaggerates hypoxemia during exercise in hypoxia. J Appl Physiol (1985) 2015; 120:351-61. [PMID: 26607244 DOI: 10.1152/japplphysiol.00210.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 11/22/2015] [Indexed: 01/11/2023] Open
Abstract
High rate of muscular oxygen utilization facilitates the development of hypoxemia during exercise at altitude. Because endurance training stimulates oxygen extraction capacity, we investigated whether endurance athletes are at higher risk to developing hypoxemia and thereby acute mountain sickness symptoms during exercise at simulated high altitude. Elite athletes (ATL; n = 8) and fit controls (CON; n = 7) cycled for 20 min at 100 W (EX100W), as well as performed an incremental maximal oxygen consumption test (EXMAX) in normobaric hypoxia (0.107 inspired O2 fraction) or normoxia (0.209 inspired O2 fraction). Cardiorespiratory responses, arterial Po2 (PaO2), and oxygenation status in m. vastus lateralis [tissue oxygenation index (TOIM)] and frontal cortex (TOIC) by near-infrared spectroscopy, were measured. Muscle O2 uptake rate was estimated from change in oxyhemoglobin concentration during a 10-min arterial occlusion in m. gastrocnemius. Maximal oxygen consumption in normoxia was 70 ± 2 ml·min(-1·)kg(-1) in ATL vs. 43 ± 2 ml·min(-1·)kg(-1) in CON, and in hypoxia decreased more in ATL (-41%) than in CON (-25%, P < 0.05). Both in normoxia at PaO2 of ∼95 Torr, and in hypoxia at PaO2 of ∼35 Torr, muscle O2 uptake was twofold higher in ATL than in CON (0.12 vs. 0.06 ml·min(-1)·100 g(-1); P < 0.05). During EX100W in hypoxia, PaO2 dropped to lower (P < 0.05) values in ATL (27.6 ± 0.7 Torr) than in CON (33.5 ± 1.0 Torr). During EXMAX, but not during EX100W, TOIM was ∼15% lower in ATL than in CON (P < 0.05). TOIC was similar between the groups at any time. This study shows that maintenance of high muscular oxygen extraction rate at very low circulating PaO2 stimulates the development of hypoxemia during submaximal exercise in hypoxia in endurance-trained individuals. This effect may predispose to premature development of acute mountain sickness symptoms during exercise at altitude.
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Affiliation(s)
- Ruud Van Thienen
- Exercise Physiology Research Group, Department of Kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Peter Hespel
- Exercise Physiology Research Group, Department of Kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium
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Liu G, Liu X, Qin Z, Gu Z, Wang G, Shi W, Wen D, Yu L, Luo Y, Xiao H. Cardiovascular System Response to Carbon Dioxide and Exercise in Oxygen-Enriched Environment at 3800 m. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:11781-96. [PMID: 26393634 PMCID: PMC4586707 DOI: 10.3390/ijerph120911781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 11/22/2022]
Abstract
Background: This study explores the responses of the cardiovascular system as humans exercise in an oxygen-enriched room at high altitude under various concentrations of CO2. Methods: The study utilized a hypobaric chamber set to the following specifications: 3800 m altitude with 25% O2 and different CO2 concentrations of 0.5% (C1), 3.0% (C2) and 5.0% (C3). Subjects exercised for 3 min three times, separated by 30 min resting periods in the above-mentioned conditions, at sea level (SL) and at 3800 m altitude (HA). The changes of heart rate variability, heart rate and blood pressure were analyzed. Results: Total power (TP) and high frequency power (HF) decreased notably during post-exercise at HA. HF increased prominently earlier the post-exercise period at 3800 m altitude with 25% O2 and 5.0% CO2 (C3), while low frequency power (LF) changed barely in all tests. The ratios of LF/HF were significantly higher during post-exercise in HA, and lower after high intensity exercise in C3. Heart rate and systolic blood pressure increased significantly in HA and C3. Conclusions: Parasympathetic activity dominated in cardiac autonomic modulation, and heart rate and blood pressure increased significantly after high intensity exercise in C3.
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Affiliation(s)
- Guohui Liu
- School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, China.
| | - Xiaopeng Liu
- High Altitude Physiology Laboratory, Institute of Aviation Medicine, Air Force, Beijing 100142, China.
| | - Zhifeng Qin
- High Altitude Physiology Laboratory, Institute of Aviation Medicine, Air Force, Beijing 100142, China.
| | - Zhao Gu
- High Altitude Physiology Laboratory, Institute of Aviation Medicine, Air Force, Beijing 100142, China.
| | - Guiyou Wang
- High Altitude Physiology Laboratory, Institute of Aviation Medicine, Air Force, Beijing 100142, China.
| | - Weiru Shi
- High Altitude Physiology Laboratory, Institute of Aviation Medicine, Air Force, Beijing 100142, China.
| | - Dongqing Wen
- High Altitude Physiology Laboratory, Institute of Aviation Medicine, Air Force, Beijing 100142, China.
| | - Lihua Yu
- High Altitude Physiology Laboratory, Institute of Aviation Medicine, Air Force, Beijing 100142, China.
| | - Yongchang Luo
- High Altitude Physiology Laboratory, Institute of Aviation Medicine, Air Force, Beijing 100142, China.
| | - Huajun Xiao
- High Altitude Physiology Laboratory, Institute of Aviation Medicine, Air Force, Beijing 100142, China.
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Puthon L, Bouzat P, Rupp T, Robach P, Favre-Juvin A, Verges S. Physiological characteristics of elite high-altitude climbers. Scand J Med Sci Sports 2015; 26:1052-9. [DOI: 10.1111/sms.12547] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2015] [Indexed: 11/27/2022]
Affiliation(s)
- L. Puthon
- HP2 Laboratory; Faculté de Médecine; Grenoble Alpes University; Batiment Jean Roget; Grenoble France
- U1042; Faculté de Médecine; INSERM; Batiment Jean Roget; Grenoble France
- Pôle Anesthésie Réanimation; CHU de Grenoble; Grenoble France
| | - P. Bouzat
- Pôle Anesthésie Réanimation; CHU de Grenoble; Grenoble France
- Grenoble Institute of Neurosciences; INSERM U836; Grenoble France
| | - T. Rupp
- Laboratoire de Physiologie de l'Exercice; Université Savoie Mont Blanc; Chambéry France
| | - P. Robach
- HP2 Laboratory; Faculté de Médecine; Grenoble Alpes University; Batiment Jean Roget; Grenoble France
- U1042; Faculté de Médecine; INSERM; Batiment Jean Roget; Grenoble France
- Medical Department; Ecole Nationale des Sports de Montagne; site de l'Ecole Nationale de Ski et d'Alpinisme; Chamonix France
| | - A. Favre-Juvin
- HP2 Laboratory; Faculté de Médecine; Grenoble Alpes University; Batiment Jean Roget; Grenoble France
- U1042; Faculté de Médecine; INSERM; Batiment Jean Roget; Grenoble France
| | - S. Verges
- HP2 Laboratory; Faculté de Médecine; Grenoble Alpes University; Batiment Jean Roget; Grenoble France
- U1042; Faculté de Médecine; INSERM; Batiment Jean Roget; Grenoble France
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Kriemler S, Radtke T, Bürgi F, Lambrecht J, Zehnder M, Brunner-La Rocca HP. Short-term cardiorespiratory adaptation to high altitude in children compared with adults. Scand J Med Sci Sports 2015; 26:147-55. [PMID: 25648726 DOI: 10.1111/sms.12422] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2014] [Indexed: 11/25/2022]
Abstract
As short-term cardiorespiratory adaptation to high altitude (HA) exposure has not yet been studied in children, we assessed acute mountain sickness (AMS), hypoxic ventilatory response (HVR) at rest and maximal exercise capacity (CPET) at low altitude (LA) and HA in pre-pubertal children and their fathers. Twenty father-child pairs (11 ± 1 years and 44 ± 4 years) were tested at LA (450 m) and HA (3450 m) at days 1, 2, and 3 after fast ascent (HA1/2/3). HVR was measured at rest and CPET was performed on a cycle ergometer. AMS severity was mild to moderate with no differences between generations. HVR was higher in children than adults at LA and increased at HA similarly in both groups. Peak oxygen uptake (VO2 peak) relative to body weight was similar in children and adults at LA and decreased significantly by 20% in both groups at HA; maximal heart rate did not change at HA in children while it decreased by 16% in adults (P < 0.001). Changes in HVR and VO2 peak from LA to HA were correlated among the biological child-father pairs. In conclusion, cardiorespiratory adaptation to altitude seems to be at least partly hereditary. Even though children and their fathers lose similar fractions of aerobic capacity going to high altitude, the mechanisms might be different.
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Affiliation(s)
- S Kriemler
- Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zurich, Switzerland
| | - T Radtke
- Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zurich, Switzerland
| | - F Bürgi
- Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zurich, Switzerland
| | - J Lambrecht
- Department of Preventive Cardiology and Sports Medicine, University Clinic for Cardiology, Inselspital, University Hospital, Berne, Switzerland
| | - M Zehnder
- Department of Clinical Research, University and Inselspital Berne, Berne, Switzerland
| | - H P Brunner-La Rocca
- Medical University Center Maastricht, Cardiology, University of Maastricht, Maastricht, The Netherlands
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27
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The application of maximal heart rate predictive equations in hypoxic conditions. Eur J Appl Physiol 2014; 115:277-84. [PMID: 25294663 DOI: 10.1007/s00421-014-3007-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 09/22/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE Peak heart rate (HRpeak) is a common tool used in exercise prescription for groups in which maximal exercise intensity is contraindicated; however, the application of this method in normobaric hypoxia is unknown. Therefore, this study investigated the response of HRpeak and the application of predictive HRpeak equations to prescribe exercise intensity in acute normobaric hypoxia. Results were used to examine whether age-derived HRpeak predictive equations are valid in hypoxic conditions. METHODS Fifteen untrained (eight men) volunteers (age 22 ± 2 years; peak rate of oxygen consumption 46.3 ± 7.0 ml kg(-1) min(-1)) completed incremental cycle ergometer tests (randomised order) to measure HRpeak at sea-level (SL (ambient inspiratory oxygen fraction (FIO2) 0.209)) and four normobaric hypoxic conditions FIO2: 0.185, 0.165, 0.142, 0.125 (≈1,000-4,000 m). RESULTS HRpeak was similar across all conditions (SL, 182 ± 13; 0.185, 178 ± 11; 0.165, 177 ± 9; 0.142, 178 ± 9; 0.125, 175 ± 10 b min(-1)) despite a reduction in oxygen saturation with increasing hypoxia (SL, 95 ± 5; 0.185, 95 ± 2; 0.165, 92 ± 2; 0.142, 88 ± 3; 0.125, 82 ± 4 %; P ≤ 0.05). The HRpeak was overestimated by all equations compared to the measured value (P < 0.05). Four equations overestimated HRpeak in all conditions (P < 0.01); two in four conditions (0.185, 0.165, 0.142, 0.125; P < 0.01); and two in three conditions (0.165, 0.142, 0.125; P < 0.01). CONCLUSION The overestimation of HRpeak by commonly used age-derived predictive equations in normobaric hypoxic conditions suggests that despite possible contraindications researchers should directly measure HRpeak whenever possible if it is to be used to prescribe exercise intensities.
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Abstract
Performance in athletic activities that include a significant aerobic component at mild or moderate altitudes shows a large individual variation. Physiologically, a large portion of the negative effect of altitude on exercise performance can be traced to limitations of oxygen diffusion, either at the level of the alveoli or the muscle microvasculature. In the lung, the ability to maintain arterial oxyhaemoglobin saturation (SaO2) appears to be a primary factor, ultimately influencing oxygen delivery to the periphery. SaO2 in hypoxia can be defended by increasing ventilatory drive; however, during heavy exercise, many athletes demonstrate limitations to expiratory flow and are unable to increase ventilation in hypoxia. Additionally, increasing ventilatory work in hypoxia may actually be negative for performance, if dyspnoea increases or muscle blood flow is reduced secondary to an increased sympathetic outflow (eg, the muscle metaboreflex response). Taken together, some athletes are clearly more negatively affected during exercise in hypoxia than other athletes. With careful screening, it may be possible to develop a protocol for determining which athletes may be the most negatively affected during competition and/or training at altitude.
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Affiliation(s)
- Robert F Chapman
- Department of Kinesiology, Indiana University, , Bloomington, Indiana, USA
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Responses to exercise in normobaric hypoxia: comparison of elite and recreational ski mountaineers. Int J Sports Physiol Perform 2014; 9:978-84. [PMID: 24664934 DOI: 10.1123/ijspp.2013-0524] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE Hypoxia is known to reduce maximal oxygen uptake (VO(2max)) more in trained than in untrained subjects in several lowland sports. Ski mountaineering is practiced mainly at altitude, so elite ski mountaineers spend significantly longer training duration at altitude than their lower-level counterparts. Since acclimatization in hypobaric hypoxia is effective, the authors hypothesized that elite ski mountaineers would exhibit a VO2max decrement in hypoxia similar to that of recreational ski mountaineers. METHODS Eleven elite (E, Swiss national team) and 12 recreational (R) ski mountaineers completed an incremental treadmill test to exhaustion in normobaric hypoxia (H, 3000 m, F(1)O(2) 14.6% ± 0.1%) and in normoxia (N, 485 m, F(1)O(2) 20.9% ± 0.0%). Pulse oxygen saturation in blood (SpO(2)), VO(2max), minute ventilation, and heart rate were recorded. RESULTS At rest, hypoxic ventilatory response was higher (P < .05) in E than in R (1.4 ± 1.9 vs 0.3 ± 0.6 L · min⁻¹ · kg⁻¹). At maximal intensity, SpO(2) was significantly lower (P < .01) in E than in R, both in N (91.1% ± 3.3% vs 94.3% ± 2.3%) and in H (76.4% ± 5.4% vs 82.3% ± 3.5%). In both groups, SpO(2) was lower (P < .01) in H. Between N and H, VO(2max) decreased to a greater extent (P < .05) in E than in R (-18% and -12%, P < .01). In E only, the VO(2max) decrement was significantly correlated with the SpO(2) decrement (r = .74, P < .01) but also with VO(2max) measured in N (r = .64, P < .05). CONCLUSION Despite a probable better acclimatization to altitude, VO(2max) was more reduced in E than in R ski mountaineers, confirming previous results observed in lowlander E athletes.
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Girard O, Amann M, Aughey R, Billaut F, Bishop DJ, Bourdon P, Buchheit M, Chapman R, D'Hooghe M, Garvican-Lewis LA, Gore CJ, Millet GP, Roach GD, Sargent C, Saunders PU, Schmidt W, Schumacher YO. Position statement--altitude training for improving team-sport players' performance: current knowledge and unresolved issues. Br J Sports Med 2013; 47 Suppl 1:i8-16. [PMID: 24282213 PMCID: PMC3903313 DOI: 10.1136/bjsports-2013-093109] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2013] [Indexed: 01/09/2023]
Abstract
Despite the limited research on the effects of altitude (or hypoxic) training interventions on team-sport performance, players from all around the world engaged in these sports are now using altitude training more than ever before. In March 2013, an Altitude Training and Team Sports conference was held in Doha, Qatar, to establish a forum of research and practical insights into this rapidly growing field. A round-table meeting in which the panellists engaged in focused discussions concluded this conference. This has resulted in the present position statement, designed to highlight some key issues raised during the debates and to integrate the ideas into a shared conceptual framework. The present signposting document has been developed for use by support teams (coaches, performance scientists, physicians, strength and conditioning staff) and other professionals who have an interest in the practical application of altitude training for team sports. After more than four decades of research, there is still no consensus on the optimal strategies to elicit the best results from altitude training in a team-sport population. However, there are some recommended strategies discussed in this position statement to adopt for improving the acclimatisation process when training/competing at altitude and for potentially enhancing sea-level performance. It is our hope that this information will be intriguing, balanced and, more importantly, stimulating to the point that it promotes constructive discussion and serves as a guide for future research aimed at advancing the bourgeoning body of knowledge in the area of altitude training for team sports.
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Affiliation(s)
- Olivier Girard
- Research and Education Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - Markus Amann
- Department of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Robert Aughey
- Exercise and Active Living, Institute of Sport, Victoria University, Melbourne, Australia
- Western Bulldogs Football Club, Melbourne, Australia
| | | | - David J Bishop
- Exercise and Active Living, Institute of Sport, Victoria University, Melbourne, Australia
| | | | | | - Robert Chapman
- Department of Kinesiology, Indiana University, High Performance Department, USA Track & Field, Indianapolis, Indiana, USA
| | - Michel D'Hooghe
- Fédération Internationale de Football Association (FIFA) Medical Commission and FIFA Medical Assessment and Research Centre (F-MARC), Langerei, 71, 8000 Brugge, Belgium
| | - Laura A Garvican-Lewis
- Department of Physiology, Australian Institute of Sport, Canberra, Australia
- University of Canberra, Canberra, Australia
| | - Christopher J Gore
- Department of Physiology, Australian Institute of Sport, Canberra, Australia
- Exercise Physiology Laboratory, Flinders University, Adelaide, Australia
| | - Grégoire P Millet
- Department of Physiology—Faculty of Biology and Medicine, ISSUL—Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Gregory D Roach
- Appleton Institute for Behavioural Science, Central Queensland University, Adelaide, Australia
| | - Charli Sargent
- Appleton Institute for Behavioural Science, Central Queensland University, Adelaide, Australia
| | - Philo U Saunders
- Department of Physiology, Australian Institute of Sport, Canberra, Australia
- University of Canberra, Canberra, Australia
| | - Walter Schmidt
- Department of Sports Medicine/Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | - Yorck O Schumacher
- Research and Education Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
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Valentini M, Revera M, Bilo G, Caldara G, Savia G, Styczkiewicz K, Parati S, Gregorini F, Faini A, Branzi G, Malfatto G, Magrì D, Agostoni P, Parati G. Effects of Beta-Blockade on Exercise Performance at High Altitude: A Randomized, Placebo-Controlled Trial Comparing the Efficacy of Nebivolol versus Carvedilol in Healthy Subjects. Cardiovasc Ther 2011; 30:240-8. [DOI: 10.1111/j.1755-5922.2011.00261.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Exercise with hypoventilation induces lower muscle oxygenation and higher blood lactate concentration: role of hypoxia and hypercapnia. Eur J Appl Physiol 2010; 110:367-77. [DOI: 10.1007/s00421-010-1512-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2010] [Indexed: 12/31/2022]
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Millet GP, Roels B, Schmitt L, Woorons X, Richalet JP. Combining hypoxic methods for peak performance. Sports Med 2010; 40:1-25. [PMID: 20020784 DOI: 10.2165/11317920-000000000-00000] [Citation(s) in RCA: 224] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
New methods and devices for pursuing performance enhancement through altitude training were developed in Scandinavia and the USA in the early 1990s. At present, several forms of hypoxic training and/or altitude exposure exist: traditional 'live high-train high' (LHTH), contemporary 'live high-train low' (LHTL), intermittent hypoxic exposure during rest (IHE) and intermittent hypoxic exposure during continuous session (IHT). Although substantial differences exist between these methods of hypoxic training and/or exposure, all have the same goal: to induce an improvement in athletic performance at sea level. They are also used for preparation for competition at altitude and/or for the acclimatization of mountaineers. The underlying mechanisms behind the effects of hypoxic training are widely debated. Although the popular view is that altitude training may lead to an increase in haematological capacity, this may not be the main, or the only, factor involved in the improvement of performance. Other central (such as ventilatory, haemodynamic or neural adaptation) or peripheral (such as muscle buffering capacity or economy) factors play an important role. LHTL was shown to be an efficient method. The optimal altitude for living high has been defined as being 2200-2500 m to provide an optimal erythropoietic effect and up to 3100 m for non-haematological parameters. The optimal duration at altitude appears to be 4 weeks for inducing accelerated erythropoiesis whereas <3 weeks (i.e. 18 days) are long enough for beneficial changes in economy, muscle buffering capacity, the hypoxic ventilatory response or Na(+)/K(+)-ATPase activity. One critical point is the daily dose of altitude. A natural altitude of 2500 m for 20-22 h/day (in fact, travelling down to the valley only for training) appears sufficient to increase erythropoiesis and improve sea-level performance. 'Longer is better' as regards haematological changes since additional benefits have been shown as hypoxic exposure increases beyond 16 h/day. The minimum daily dose for stimulating erythropoiesis seems to be 12 h/day. For non-haematological changes, the implementation of a much shorter duration of exposure seems possible. Athletes could take advantage of IHT, which seems more beneficial than IHE in performance enhancement. The intensity of hypoxic exercise might play a role on adaptations at the molecular level in skeletal muscle tissue. There is clear evidence that intense exercise at high altitude stimulates to a greater extent muscle adaptations for both aerobic and anaerobic exercises and limits the decrease in power. So although IHT induces no increase in VO(2max) due to the low 'altitude dose', improvement in athletic performance is likely to happen with high-intensity exercise (i.e. above the ventilatory threshold) due to an increase in mitochondrial efficiency and pH/lactate regulation. We propose a new combination of hypoxic method (which we suggest naming Living High-Training Low and High, interspersed; LHTLHi) combining LHTL (five nights at 3000 m and two nights at sea level) with training at sea level except for a few (2.3 per week) IHT sessions of supra-threshold training. This review also provides a rationale on how to combine the different hypoxic methods and suggests advances in both their implementation and their periodization during the yearly training programme of athletes competing in endurance, glycolytic or intermittent sports.
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Affiliation(s)
- Gregoire P Millet
- ISSUL, Institute of Sport Science, University of Lausanne, Lausanne, Switzerland.
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Bourdillon N, Mollard P, Letournel M, Beaudry M, Richalet JP. Interaction between hypoxia and training on NIRS signal during exercise: Contribution of a mathematical model. Respir Physiol Neurobiol 2009; 169:50-61. [DOI: 10.1016/j.resp.2009.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 08/17/2009] [Accepted: 08/19/2009] [Indexed: 10/20/2022]
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White M, Touyz R, Tessier Y, Van Le V, Ross H, Sirois MG. A Cardiac and a Kidney Transplant Patient Above 6000 Meters in Bolivia. Wilderness Environ Med 2009; 20:99-100. [DOI: 10.1580/08-weme-le-249.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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36
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Bourdillon N, Mollard P, Letournel M, Beaudry M, Richalet JP. Non-invasive evaluation of the capillary recruitment in the human muscle during exercise in hypoxia. Respir Physiol Neurobiol 2009; 165:237-44. [DOI: 10.1016/j.resp.2008.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Revised: 11/10/2008] [Accepted: 12/12/2008] [Indexed: 10/21/2022]
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Bhaumik G, Dass D, Lama H, Chauhan SKS. Maximum exercise responses of men and women mountaineering trainees on induction to high altitude (4350 m) by trekking. Wilderness Environ Med 2008; 19:151-6. [PMID: 18715126 DOI: 10.1580/07-weme-or-121.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE Maximum aerobic capacity decreases at high altitude. This study was conducted to compare the changes in maximum aerobic capacity in men and women mountaineering trainees on induction to high altitude at 4350 m by trekking. METHODS Eight men and 8 women mountaineering trainees in a mountaineering course were selected for the study. The initial study was conducted at 2100 m (586 mm Hg) and then during 6 to 7 days of sojourn at 4350 m (435 mm Hg). Maximum oxygen consumption (VO(2max)), maximum heart rate (HR(max)), pulse arterial oxygen saturation (SaO(2)), and maximum ventilation (VE(max)) were measured. RESULTS VO(2max), HR(max), duration of work (minutes), and SaO(2) saturation decreased significantly (P < .05) with increasing altitude in both sexes. Conversely, VE(max) and ventilatory equivalent (VE/VO(2)) increased significantly (P < .05). Men showed a relatively higher value of maximum exercise variables (total exercise time, exercise intensity, and VO(2)) than women trainees at both altitude locations. The decrement of VO(2max) was 13% in women and 17% in men (P < .05). CONCLUSIONS The results indicate that the decrement of maximum aerobic capacity at 4350 m was less in women than in men under similar modes of ascent.
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Affiliation(s)
- Gopinath Bhaumik
- Environmental Physiology Division, Defence Institute of Physiology, Allied Science Defence Research and Development Organization, Timarpur, Delhi, India.
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The oxygen delivery response to acute hypoxia during incremental knee extension exercise differs in active and trained males. DYNAMIC MEDICINE : DM 2008; 7:11. [PMID: 18700024 PMCID: PMC2526084 DOI: 10.1186/1476-5918-7-11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Accepted: 08/12/2008] [Indexed: 11/10/2022]
Abstract
Background It is well known that hypoxic exercise in healthy individuals increases limb blood flow, leg oxygen extraction and limb vascular conductance during knee extension exercise. However, the effect of hypoxia on cardiac output, and total vascular conductance is less clear. Furthermore, the oxygen delivery response to hypoxic exercise in well trained individuals is not well known. Therefore our aim was to determine the cardiac output (Doppler echocardiography), vascular conductance, limb blood flow (Doppler echocardiography) and muscle oxygenation response during hypoxic knee extension in normally active and endurance-trained males. Methods Ten normally active and nine endurance-trained males (VO2max = 46.1 and 65.5 mL/kg/min, respectively) performed 2 leg knee extension at 25, 50, 75 and 100% of their maximum intensity in both normoxic and hypoxic conditions (FIO2 = 15%; randomized order). Results were analyzed with a 2-way mixed model ANOVA (group × intensity). Results The main finding was that in normally active individuals hypoxic sub-maximal exercise (25 – 75% of maximum intensity) brought about a 3 fold increase in limb blood flow but decreased stroke volume compared to normoxia. In the trained group there were no significant changes in stroke volume, cardiac output and limb blood flow at sub-maximal intensities (compared to normoxia). During maximal intensity hypoxic exercise limb blood flow increased approximately 300 mL/min compared to maximal intensity normoxic exercise. Conclusion Cardiorespiratory fitness likely influences the oxygen delivery response to hypoxic exercise both at a systemic and limb level. The increase in limb blood flow during maximal exercise in hypoxia (both active and trained individuals) suggests a hypoxic stimulus that is not present in normoxic conditions.
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Myers SD, Biccard BM, Chan C, Imray CHE, Wright AD, Pattinson KTS. Delayed acclimatization of the ventilatory threshold in healthy trekkers. Wilderness Environ Med 2008; 19:124-8. [PMID: 18513104 DOI: 10.1580/07-weme-br-1271.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To test the hypothesis that acclimatization to high altitude results in an improvement of the ventilatory threshold (VT). METHODS Eight lowlanders underwent cardiopulmonary exercise testing with a cycle ergometer to determine VT and peak oxygen uptake (Vo2peak) in Coventry, United Kingdom (altitude: 80 m), on arrival in leh, india (altitude: 3500 m), and after 12 days of acclimatization that included a 5-day high altitude trek up to 4770 m. RESULTS Vo2peak fell on arrival at 3500 m and remained depressed at 12 days. VT was depressed on arrival at high altitude and was further depressed at 12 days. VT as a proportion of the Vo2peak was decreased on arrival at high altitude, and after acclimatization, this relationship was further decreased. CONCLUSIONS Individuals who are sedentary or not participating in regular physical training appear to require a longer period of acclimatization than trained athletes. With the increasing numbers participating in high-altitude trekking and charity climbs of peaks, such as Mt. Kilimanjaro, this information has clinically significant practical implications for those leading or acting as medical advisors.
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Affiliation(s)
- Stephen D Myers
- School of Sport, Exercise and Health Sciences, University of Chichester, College Lane, Chichester, West Sussex, United Kingdom
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Mollard P, Woorons X, Antoine-Jonville S, Jutand L, Richalet JP, Favret F, Pichon A. ‘Oxygen uptake efficiency slope’ in trained and untrained subjects exposed to hypoxia. Respir Physiol Neurobiol 2008; 161:167-73. [DOI: 10.1016/j.resp.2008.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Revised: 01/25/2008] [Accepted: 01/26/2008] [Indexed: 12/19/2022]
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Favret F, Richalet JP. Exercise and hypoxia: The role of the autonomic nervous system. Respir Physiol Neurobiol 2007; 158:280-6. [PMID: 17521971 DOI: 10.1016/j.resp.2007.04.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 03/14/2007] [Accepted: 04/05/2007] [Indexed: 10/23/2022]
Abstract
The reduction in maximal oxygen consumption in hypoxia can be due to physiological factors, the relative importance of which depends on the degree of hypoxia: the reduction in inspired PO2, the impairment of lung gas exchange contributing to an exercise-induced decrease in arterial O(2) saturation, the reduction in maximal cardiac output and the limitation in tissue diffusion. This paper focuses on two aspects of this oxygen cascade. First, the decrease in heart rate at maximal exercise in prolonged exposure to hypoxia is discussed and the role of changes in the autonomous nervous system is emphasised. The desensitization of the beta-adrenergic pathway and the upregulation of the muscarinic pathway, both using G-protein systems, contribute to limit the myocardial O(2) consumption in face of reduced O(2) availability during maximal exercise in hypoxia. The changes in O(2) diffusion to the tissues are discussed in relation to the expression of hypoxia inducible factor (HIF-1alpha) and vascular endothelial growth factor (VEGF) and their possible changes induced by training and/or hypoxic exposure.
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Affiliation(s)
- Fabrice Favret
- Université Paris 13, Laboratoire EA2363 Réponses Cellulaires et Fonctionnelles à l'hypoxie, 74 rue Marcel Cachin, Bobigny, France
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Mollard P, Woorons X, Letournel M, Lamberto C, Favret F, Pichon A, Beaudry M, Richalet JP. Determinant factors of the decrease in aerobic performance in moderate acute hypoxia in women endurance athletes. Respir Physiol Neurobiol 2007; 159:178-86. [PMID: 17766196 DOI: 10.1016/j.resp.2007.06.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Revised: 06/23/2007] [Accepted: 06/23/2007] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to evaluate the limiting factors of maximal aerobic performance in endurance trained (TW) and sedentary (UW) women. Subjects performed four incremental tests on a cycle ergometer at sea level and in normobaric hypoxia corresponding to 1000, 2500 and 4500 m. Maximal oxygen uptake decrement (Delta VO2 max) was larger in TW at each altitude. Maximal heart rate and ventilation decreased at 4500 m in TW. Maximal cardiac output remained unchanged. In both groups, arterialized oxygen saturation (Sa'O2 max) decreased at and above 2500 m and maximal O2 transport (QaO2 max) decreased from 1000 m. At 4500 m, there was no more difference in QaO2 max between TW and UW. Mixed venous O2 pressure (PvO2 max) was lower and O2 extraction (O2ERmax) greater in TW at each altitude. The primary determinant factor of VO2 max decrement in moderate acute hypoxia in trained and untrained women is a reduced maximal O2 transport that cannot be compensate by tissue O2 extraction.
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Affiliation(s)
- Pascal Mollard
- Université Paris 13, Laboratoire Réponses cellulaires et fonctionnelles à l'hypoxie, EA2363, ARPE, 74 rue Marcel Cachin, 93017 Bobigny Cedex, France.
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