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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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3
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Nybo L, Rønnestad B, Lundby C. High or hot-Perspectives on altitude camps and heat-acclimation training as preparation for prolonged stage races. Scand J Med Sci Sports 2024; 34:e14268. [PMID: 36350277 DOI: 10.1111/sms.14268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 11/11/2022]
Abstract
Adaptation to heat stress and hypoxia are relevant for athletes participating in Tour de France or similar cycling races taking place during the summertime in landscapes with varying altitude. Both to minimize detrimental performance effects associated with arterial desaturation occurring at moderate altitudes in elite athletes, respectively, reduce the risk of hyperthermia on hot days, but also as a pre-competition acclimatization strategy to boost blood volume in already highly adapted athletes. The hematological adaptations require weeks of exposure to manifest, but are attractive as an augmented hemoglobin mass may improve arterial oxygen delivery and hence benefit prolonged performances. Altitude training camps have in this context a long history in exercise physiology and are still common practice in elite cycling. However, heat-acclimation training provides an attractive alternative for some athletes either as a stand-alone approach or in combination with altitude. The present paper provides an update and practical perspectives on the potential to utilize hypoxia and heat exposure to optimize hematological adaptations. Furthermore, we will consider temporal aspects both in terms of onset and decay of the adaptations relevant for improved thermoregulatory capacity and respiratory adaptations to abate arterial desaturation during altitude exposure. From focus on involved physiological mechanisms, time course, and responsiveness in elite athletes, we will provide guidance based on our experience from practical implementation in cyclists preparing for prolonged stage races such as the Tour de France.
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Affiliation(s)
- Lars Nybo
- Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark
| | - Bent Rønnestad
- Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Carsten Lundby
- Inland Norway University of Applied Sciences, Lillehammer, Norway
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Webb KL, Gorman EK, Morkeberg OH, Klassen SA, Regimbal RJ, Wiggins CC, Joyner MJ, Hammer SM, Senefeld JW. The relationship between hemoglobin and [Formula: see text]: A systematic review and meta-analysis. PLoS One 2023; 18:e0292835. [PMID: 37824583 PMCID: PMC10569622 DOI: 10.1371/journal.pone.0292835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 09/29/2023] [Indexed: 10/14/2023] Open
Abstract
OBJECTIVE There is widespread agreement about the key role of hemoglobin for oxygen transport. Both observational and interventional studies have examined the relationship between hemoglobin levels and maximal oxygen uptake ([Formula: see text]) in humans. However, there exists considerable variability in the scientific literature regarding the potential relationship between hemoglobin and [Formula: see text]. Thus, we aimed to provide a comprehensive analysis of the diverse literature and examine the relationship between hemoglobin levels (hemoglobin concentration and mass) and [Formula: see text] (absolute and relative [Formula: see text]) among both observational and interventional studies. METHODS A systematic search was performed on December 6th, 2021. The study procedures and reporting of findings followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Article selection and data abstraction were performed in duplicate by two independent reviewers. Primary outcomes were hemoglobin levels and [Formula: see text] values (absolute and relative). For observational studies, meta-regression models were performed to examine the relationship between hemoglobin levels and [Formula: see text] values. For interventional studies, meta-analysis models were performed to determine the change in [Formula: see text] values (standard paired difference) associated with interventions designed to modify hemoglobin levels or [Formula: see text]. Meta-regression models were then performed to determine the relationship between a change in hemoglobin levels and the change in [Formula: see text] values. RESULTS Data from 384 studies (226 observational studies and 158 interventional studies) were examined. For observational data, there was a positive association between absolute [Formula: see text] and hemoglobin levels (hemoglobin concentration, hemoglobin mass, and hematocrit (P<0.001 for all)). Prespecified subgroup analyses demonstrated no apparent sex-related differences among these relationships. For interventional data, there was a positive association between the change of absolute [Formula: see text] (standard paired difference) and the change in hemoglobin levels (hemoglobin concentration (P<0.0001) and hemoglobin mass (P = 0.006)). CONCLUSION These findings suggest that [Formula: see text] values are closely associated with hemoglobin levels among both observational and interventional studies. Although our findings suggest a lack of sex differences in these relationships, there were limited studies incorporating females or stratifying results by biological sex.
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Affiliation(s)
- Kevin L. Webb
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Ellen K. Gorman
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Olaf H. Morkeberg
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Stephen A. Klassen
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Riley J. Regimbal
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Chad C. Wiggins
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Michael J. Joyner
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Shane M. Hammer
- Department of Kinesiology, Applied Health, and Recreation, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Jonathon W. Senefeld
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois
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5
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Doherty CJ, Chang JC, Thompson BP, Swenson ER, Foster GE, Dominelli PB. The Impact of Acetazolamide and Methazolamide on Exercise Performance in Normoxia and Hypoxia. High Alt Med Biol 2023; 24:7-18. [PMID: 36802203 DOI: 10.1089/ham.2022.0134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Doherty, Connor J., Jou-Chung Chang, Benjamin P. Thompson, Erik R. Swenson, Glen E. Foster, and Paolo B. Dominelli. The impact of acetazolamide and methazolamide on exercise performance in normoxia and hypoxia. High Alt Med Biol. 24:7-18, 2023.-Carbonic anhydrase (CA) inhibitors are commonly prescribed for acute mountain sickness (AMS). In this review, we sought to examine how two CA inhibitors, acetazolamide (AZ) and methazolamide (MZ), affect exercise performance in normoxia and hypoxia. First, we briefly describe the role of CA inhibition in facilitating the increase in ventilation and arterial oxygenation in preventing and treating AMS. Next, we detail how AZ affects exercise performance in normoxia and hypoxia and this is followed by a discussion on MZ. We emphasize that the overarching focus of the review is how the two drugs potentially affect exercise performance, rather than their ability to prevent/treat AMS per se, their interrelationship will be discussed. Overall, we suggest that AZ hinders exercise performance in normoxia, but may be beneficial in hypoxia. Based upon head-to-head studies of AZ and MZ in humans on diaphragmatic and locomotor strength in normoxia, MZ may be a better CA inhibitor when exercise performance is crucial at high altitude.
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Affiliation(s)
- Connor J Doherty
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Jou-Chung Chang
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Benjamin P Thompson
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Erik R Swenson
- Division of Pulmonary, Critical Care and Sleep Medicine, University of Washington, Washington, USA
- Medical Service, VA Puget Sound Health Care System, Seattle, Washington, USA
| | - Glen E Foster
- School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Paolo B Dominelli
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
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6
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Viscor G, Corominas J, Carceller A. Nutrition and Hydration for High-Altitude Alpinism: A Narrative Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:3186. [PMID: 36833880 PMCID: PMC9965509 DOI: 10.3390/ijerph20043186] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/03/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
This report aims to summarise the scientific knowledge around hydration, nutrition, and metabolism at high altitudes and to transfer it into the practical context of extreme altitude alpinism, which, as far as we know, has never been considered before in the literature. Maintaining energy balance during alpine expeditions is difficult for several reasons and requires a deep understanding of human physiology and the biological basis for altitude acclimation. However, in these harsh conditions it is difficult to reconcile our current scientific knowledge in sports nutrition or even for mountaineering to high-altitude alpinism: extreme hypoxia, cold, and the logistical difficulties intrinsic to these kinds of expeditions are not considered in the current literature. Requirements for the different stages of an expedition vary dramatically with increasing altitude, so recommendations must differentiate whether the alpinist is at base camp, at high-altitude camps, or attempting the summit. This paper highlights nutritional recommendations regarding prioritising carbohydrates as a source of energy and trying to maintain a protein balance with a practical contextualisation in the extreme altitude environment in the different stages of an alpine expedition. More research is needed regarding specific macro and micronutrient requirements as well as the adequacy of nutritional supplementations at high altitudes.
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Affiliation(s)
- Ginés Viscor
- Secció de Fisiologia, Departament de Biologia Cel·Lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Jordi Corominas
- International Federation of Mountain Guide Associations (UIAGM/IFMGA), CH-1920 Bern, Switzerland
| | - Anna Carceller
- Secció de Fisiologia, Departament de Biologia Cel·Lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain
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7
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Furian M, Tannheimer M, Burtscher M. Effects of Acute Exposure and Acclimatization to High-Altitude on Oxygen Saturation and Related Cardiorespiratory Fitness in Health and Disease. J Clin Med 2022; 11:jcm11226699. [PMID: 36431176 PMCID: PMC9697047 DOI: 10.3390/jcm11226699] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Maximal values of aerobic power (VO2max) and peripheral oxygen saturation (SpO2max) decline in parallel with gain in altitude. Whereas this relationship has been well investigated when acutely exposed to high altitude, potential benefits of acclimatization on SpO2 and related VO2max in healthy and diseased individuals have been much less considered. Therefore, this narrative review was primarily aimed to identify relevant literature reporting altitude-dependent changes in determinants, in particular SpO2, of VO2max and effects of acclimatization in athletes, healthy non-athletes, and patients suffering from cardiovascular, respiratory and/or metabolic diseases. Moreover, focus was set on potential differences with regard to baseline exercise performance, age and sex. Main findings of this review emphasize the close association between individual SpO2 and VO2max, and demonstrate similar altitude effects (acute and during acclimatization) in healthy people and those suffering from cardiovascular and metabolic diseases. However, in patients with ventilatory constrains, i.e., chronic obstructive pulmonary disease, steep decline in SpO2 and V̇O2max and reduced potential to acclimatize stress the already low exercise performance. Finally, implications for prevention and therapy are briefly discussed.
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Affiliation(s)
- Michael Furian
- Pulmonary Division, University Hospital Zurich, 8092 Zurich, Switzerland
- Research Department, Swiss University of Traditional Chinese Medicine, 5330 Bad Zurzach, Switzerland
| | - Markus Tannheimer
- Department of Sport and Rehabilitation Medicine, University of Ulm, 89075 Ulm, Germany
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, 6020 Innsbruck, Austria
- Correspondence:
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8
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Williams AM, Levine BD, Stembridge M. A change of heart: mechanisms of cardiac adaptation to acute and chronic hypoxia. J Physiol 2022; 600:4089-4104. [PMID: 35930370 PMCID: PMC9544656 DOI: 10.1113/jp281724] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 07/21/2022] [Indexed: 11/20/2022] Open
Abstract
Over the last 100 years, high‐altitude researchers have amassed a comprehensive understanding of the global cardiac responses to acute, prolonged and lifelong hypoxia. When lowlanders are exposed to hypoxia, the drop in arterial oxygen content demands an increase in cardiac output, which is facilitated by an elevated heart rate at the same time as ventricular volumes are maintained. As exposure is prolonged, haemoconcentration restores arterial oxygen content, whereas left ventricular filling and stroke volume are lowered as a result of a combination of reduced blood volume and hypoxic pulmonary vasoconstriction. Populations native to high‐altitude, such as the Sherpa in Asia, exhibit unique lifelong or generational adaptations to hypoxia. For example, they have smaller left ventricular volumes compared to lowlanders despite having larger total blood volume. More recent investigations have begun to explore the mechanisms underlying such adaptive responses by combining novel imaging techniques with interventions that manipulate cardiac preload, afterload, and/or contractility. This work has revealed the contributions and interactions of (i) plasma volume constriction; (ii) sympathoexcitation; and (iii) hypoxic pulmonary vasoconstriction with respect to altering cardiac loading, or otherwise preserving or enhancing biventricular systolic and diastolic function even amongst high altitude natives with excessive erythrocytosis. Despite these advances, various areas of investigation remain understudied, including potential sex‐related differences in response to high altitude. Collectively, the available evidence supports the conclusion that the human heart successfully adapts to hypoxia over the short‐ and long‐term, without signs of myocardial dysfunction in healthy humans, except in very rare cases of maladaptation.
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Affiliation(s)
- Alexandra M Williams
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
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Płoszczyca K, Chalimoniuk M, Przybylska I, Czuba M. Effects of Short-Term Phosphate Loading on Aerobic Capacity under Acute Hypoxia in Cyclists: A Randomized, Placebo-Controlled, Crossover Study. Nutrients 2022; 14:236. [PMID: 35057416 PMCID: PMC8778537 DOI: 10.3390/nu14020236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/01/2022] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
The aim of this study was to evaluate the effects of sodium phosphate (SP) supplementation on aerobic capacity in hypoxia. Twenty-four trained male cyclists received SP (50 mg·kg-1 of FFM/day) or placebo for six days in a randomized, crossover study, with a three-week washout period between supplementation phases. Before and after each supplementation phase, the subjects performed an incremental exercise test to exhaustion in hypoxia (FiO2 = 16%). Additionally, the levels of 2,3-diphosphoglycerate (2,3-DPG), hypoxia-inducible factor 1 alpha (HIF-1α), inorganic phosphate (Pi), calcium (Ca), parathyroid hormone (PTH) and acid-base balance were determined. The results showed that phosphate loading significantly increased the Pi level by 9.0%, whereas 2,3-DPG levels, hemoglobin oxygen affinity, buffering capacity and myocardial efficiency remained unchanged. The aerobic capacity in hypoxia was not improved following SP. Additionally, our data revealed high inter-individual variability in response to SP. Therefore, the participants were grouped as Responders and Non-Responders. In the Responders, a significant increase in aerobic performance in the range of 3-5% was observed. In conclusion, SP supplementation is not an ergogenic aid for aerobic capacity in hypoxia. However, in certain individuals, some benefits can be expected, but mainly in athletes with less training-induced central and/or peripheral adaptation.
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Affiliation(s)
- Kamila Płoszczyca
- Department of Kinesiology, Institute of Sport, 01-982 Warsaw, Poland
| | - Małgorzata Chalimoniuk
- Department of Physiotherapy, Faculty of Physical Education and Health in Biala Podlaska, Jozef Pilsudski University of Physical Education in Warsaw, 21-500 Biala Podlaska, Poland
| | - Iwona Przybylska
- Department of Physiotherapy, Faculty of Physical Education and Health in Biala Podlaska, Jozef Pilsudski University of Physical Education in Warsaw, 21-500 Biala Podlaska, Poland
| | - Miłosz Czuba
- Department of Kinesiology, Institute of Sport, 01-982 Warsaw, Poland
- Faculty of Rehabilitation, Jozef Pilsudski University of Physical Education in Warsaw, 00-968 Warsaw, Poland
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10
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Ade CJ, Turpin VRG, Parr SK, Hammond ST, White Z, Weber RE, Schulze KM, Colburn TD, Poole DC. Does wearing a facemask decrease arterial blood oxygenation and impair exercise tolerance? Respir Physiol Neurobiol 2021; 294:103765. [PMID: 34352384 PMCID: PMC9715989 DOI: 10.1016/j.resp.2021.103765] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/12/2021] [Accepted: 07/25/2021] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Concerns have been raised that COVID-19 face coverings compromise lung function and pulmonary gas exchange to the extent that they produce arterial hypoxemia and hypercapnia during high intensity exercise resulting in exercise intolerance in recreational exercisers. This study therefore aimed to investigate the effects of a surgical, flannel or vertical-fold N95 masks on cardiorespiratory responses to incremental exercise. METHODS This investigation studied 11 adult males and females at rest and while performing progressive cycle exercise to exhaustion. We tested the hypotheses that wearing a surgical (S), flannel (F) or horizontal-fold N95 mask compared to no mask (control) would not promote arterial deoxygenation or exercise intolerance nor alter primary cardiovascular variables during submaximal or maximal exercise. RESULTS Despite the masks significantly increasing end-expired peri-oral %CO2 and reducing %O2, each ∼0.8-2% during exercise (P < 0.05), our results supported the hypotheses. Specifically, none of these masks reduced sub-maximal or maximal exercise arterial O2 saturation (P = 0.744), but ratings of dyspnea were significantly increased (P = 0.007). Moreover, maximal exercise capacity was not compromised nor were there any significant alterations of primary cardiovascular responses (mean arterial pressure, stroke volume, cardiac output) found during sub-maximal exercise. CONCLUSION Whereas these results are for young healthy recreational male and female exercisers and cannot be applied directly to elite athletes, older or patient populations, they do support that arterial hypoxemia and exercise intolerance are not the obligatory consequences of COVID-19-indicated mask-wearing at least for cycling exercise.
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Affiliation(s)
- Carl J Ade
- Departments of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA.
| | | | - Shannon K Parr
- Departments of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Stephen T Hammond
- Departments of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Zachary White
- Departments of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Ramona E Weber
- Departments of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA; Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Kiana M Schulze
- Departments of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA; Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Trenton D Colburn
- Departments of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA; Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - David C Poole
- Departments of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA; Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
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11
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Collins SÉ, Phillips DB, Brotto AR, Rampuri ZH, Stickland MK. Ventilatory efficiency in athletes, asthma and obesity. Eur Respir Rev 2021; 30:30/161/200206. [PMID: 34289980 DOI: 10.1183/16000617.0206-2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/16/2020] [Indexed: 11/05/2022] Open
Abstract
During submaximal exercise, minute ventilation (V' E) increases in proportion to metabolic rate (i.e. carbon dioxide production (V' CO2 )) to maintain arterial blood gas homeostasis. The ratio V' E/V' CO2 , commonly termed ventilatory efficiency, is a useful tool to evaluate exercise responses in healthy individuals and patients with chronic disease. Emerging research has shown abnormal ventilatory responses to exercise (either elevated or blunted V' E/V' CO2 ) in some chronic respiratory and cardiovascular conditions. This review will briefly provide an overview of the physiology of ventilatory efficiency, before describing the ventilatory responses to exercise in healthy trained endurance athletes, patients with asthma, and patients with obesity. During submaximal exercise, the V' E/V' CO2 response is generally normal in endurance-trained individuals, patients with asthma and patients with obesity. However, in endurance-trained individuals, asthmatics who demonstrate exercise induced-bronchoconstriction, and morbidly obese individuals, the V' E/V' CO2 can be blunted at maximal exercise, likely because of mechanical ventilatory constraint.
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Affiliation(s)
- Sophie É Collins
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
| | - Devin B Phillips
- Respiratory Investigation Unit, Department of Medicine, Queen's University, Kingston, Canada
| | - Andrew R Brotto
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Zahrah H Rampuri
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
| | - Michael K Stickland
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.,G.F. MacDonald Centre for Lung Health, Covenant Health, Edmonton, Canada
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12
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Mallet RT, Burtscher J, Richalet JP, Millet GP, Burtscher M. Impact of High Altitude on Cardiovascular Health: Current Perspectives. Vasc Health Risk Manag 2021; 17:317-335. [PMID: 34135590 PMCID: PMC8197622 DOI: 10.2147/vhrm.s294121] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022] Open
Abstract
Globally, about 400 million people reside at terrestrial altitudes above 1500 m, and more than 100 million lowlanders visit mountainous areas above 2500 m annually. The interactions between the low barometric pressure and partial pressure of O2, climate, individual genetic, lifestyle and socio-economic factors, as well as adaptation and acclimatization processes at high elevations are extremely complex. It is challenging to decipher the effects of these myriad factors on the cardiovascular health in high altitude residents, and even more so in those ascending to high altitudes with or without preexisting diseases. This review aims to interpret epidemiological observations in high-altitude populations; present and discuss cardiovascular responses to acute and subacute high-altitude exposure in general and more specifically in people with preexisting cardiovascular diseases; the relations between cardiovascular pathologies and neurodegenerative diseases at altitude; the effects of high-altitude exercise; and the putative cardioprotective mechanisms of hypobaric hypoxia.
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Affiliation(s)
- Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
- Institute of Sport Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Jean-Paul Richalet
- Laboratoire Hypoxie & Poumon, UMR Inserm U1272, Université Sorbonne Paris Nord 13, Bobigny Cedex, F-93017, France
| | - Gregoire P Millet
- Department of Biomedical Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
- Institute of Sport Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, A-6020, Austria
- Austrian Society for Alpine and High-Altitude Medicine, Mieming, Austria
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13
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Doherty CJ, Mann LM, Angus SA, Chan JS, Molgat-Seon Y, Dominelli PB. Impact of wearing a surgical and cloth mask during cycle exercise. Appl Physiol Nutr Metab 2021; 46:753-762. [PMID: 33960846 DOI: 10.1139/apnm-2021-0190] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We sought to determine the impact of wearing cloth or surgical masks on the cardiopulmonary responses to moderate-intensity exercise. Twelve subjects (n = 5 females) completed three, 8-min cycling trials while breathing through a non-rebreathing valve (laboratory control), cloth, or surgical mask. Heart rate (HR), oxyhemoglobin saturation (SpO2), breathing frequency, mouth pressure, partial pressure of end-tidal carbon dioxide (PetCO2) and oxygen (PetO2), dyspnea were measured throughout exercise. A subset of n = 6 subjects completed an additional exercise bout without a mask (ecological control). There were no differences in breathing frequency, HR or SpO2 across conditions (all p > 0.05). Compared with the laboratory control (4.7 ± 0.9 cmH2O [mean ± SD]), mouth pressure swings were smaller with the surgical mask (0.9 ± 0.7; p < 0.0001), but similar with the cloth mask (3.6 ± 4.8 cmH2O; p = 0.66). Wearing a cloth mask decreased PetO2 (-3.5 ± 3.7 mm Hg) and increased PetCO2 (+2.0 ± 1.3 mm Hg) relative to the ecological control (both p < 0.05). There were no differences in end-tidal gases between mask conditions and laboratory control (both p > 0.05). Dyspnea was similar between the control conditions and the surgical mask (p > 0.05) but was greater with the cloth mask compared with laboratory (+0.9 ± 1.2) and ecological (+1.5 ± 1.3) control conditions (both p < 0.05). Wearing a mask during short-term moderate-intensity exercise may increase dyspnea but has minimal impact on the cardiopulmonary response. Novelty: Wearing surgical or cloth masks during exercise has no impact on breathing frequency, tidal volume, oxygenation, and heart rate However, there are some changes in inspired and expired gas fractions that are physiologically irrelevant. In young healthy individuals, wearing surgical or cloth masks during submaximal exercise has few physiological consequences.
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Affiliation(s)
- Connor J Doherty
- Department of Kinesiology, Faculty of Health, University of Waterloo, Waterloo, Ontario, Canada
| | - Leah M Mann
- Department of Kinesiology, Faculty of Health, University of Waterloo, Waterloo, Ontario, Canada
| | - Sarah A Angus
- Department of Kinesiology, Faculty of Health, University of Waterloo, Waterloo, Ontario, Canada
| | - Jason S Chan
- Department of Kinesiology, Faculty of Health, University of Waterloo, Waterloo, Ontario, Canada
| | - Yannick Molgat-Seon
- Centre for Heart Lung Innovation, St. Paul's Hospital, The University of British Columbia, Vancouver, British Columbia, Canada.,The Gupta Faculty of Kinesiology and Applied Health, University of Winnipeg, Winnipeg, Manitoba, Canada
| | - Paolo B Dominelli
- Department of Kinesiology, Faculty of Health, University of Waterloo, Waterloo, Ontario, Canada
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14
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Dempsey JA, La Gerche A, Hull JH. Is the healthy respiratory system built just right, overbuilt, or underbuilt to meet the demands imposed by exercise? J Appl Physiol (1985) 2020; 129:1235-1256. [PMID: 32790594 DOI: 10.1152/japplphysiol.00444.2020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In the healthy, untrained young adult, a case is made for a respiratory system (airways, pulmonary vasculature, lung parenchyma, respiratory muscles, and neural ventilatory control system) that is near ideally designed to ensure a highly efficient, homeostatic response to exercise of varying intensities and durations. Our aim was then to consider circumstances in which the intra/extrathoracic airways, pulmonary vasculature, respiratory muscles, and/or blood-gas distribution are underbuilt or inadequately regulated relative to the demands imposed by the cardiovascular system. In these instances, the respiratory system presents a significant limitation to O2 transport and contributes to the occurrence of locomotor muscle fatigue, inhibition of central locomotor output, and exercise performance. Most prominent in these examples of an "underbuilt" respiratory system are highly trained endurance athletes, with additional influences of sex, aging, hypoxic environments, and the highly inbred equine. We summarize by evaluating the relative influences of these respiratory system limitations on exercise performance and their impact on pathophysiology and provide recommendations for future investigation.
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Affiliation(s)
- Jerome A Dempsey
- John Robert Sutton Professor of Population Health Sciences, John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Andre La Gerche
- Clinical Research Domain, Baker Heart and Diabetes Institute, Melbourne, Australia.,National Center for Sports Cardiology, St. Vincent's Hospital, Melbourne, Fitzroy, Australia
| | - James H Hull
- Department of Respiratory Medicine, Royal Brompton Hospital, London, United Kingdom.,Institute of Sport, Exercise and Health (ISEH), University College London, United Kingdom
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15
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Mujika I, Sharma AP, Stellingwerff T. Contemporary Periodization of Altitude Training for Elite Endurance Athletes: A Narrative Review. Sports Med 2020; 49:1651-1669. [PMID: 31452130 DOI: 10.1007/s40279-019-01165-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Since the 1960s there has been an escalation in the purposeful utilization of altitude to enhance endurance athletic performance. This has been mirrored by a parallel intensification in research pursuits to elucidate hypoxia-induced adaptive mechanisms and substantiate optimal altitude protocols (e.g., hypoxic dose, duration, timing, and confounding factors such as training load periodization, health status, individual response, and nutritional considerations). The majority of the research and the field-based rationale for altitude has focused on hematological outcomes, where hypoxia causes an increased erythropoietic response resulting in augmented hemoglobin mass. Hypoxia-induced non-hematological adaptations, such as mitochondrial gene expression and enhanced muscle buffering capacity may also impact athletic performance, but research in elite endurance athletes is limited. However, despite significant scientific progress in our understanding of hypobaric hypoxia (natural altitude) and normobaric hypoxia (simulated altitude), elite endurance athletes and coaches still tend to be trailblazers at the coal face of cutting-edge altitude application to optimize individual performance, and they already implement novel altitude training interventions and progressive periodization and monitoring approaches. Published and field-based data strongly suggest that altitude training in elite endurance athletes should follow a long- and short-term periodized approach, integrating exercise training and recovery manipulation, performance peaking, adaptation monitoring, nutritional approaches, and the use of normobaric hypoxia in conjunction with terrestrial altitude. Future research should focus on the long-term effects of accumulated altitude training through repeated exposures, the interactions between altitude and other components of a periodized approach to elite athletic preparation, and the time course of non-hematological hypoxic adaptation and de-adaptation, and the potential differences in exercise-induced altitude adaptations between different modes of exercise.
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Affiliation(s)
- Iñigo Mujika
- Department of Physiology, Faculty of Medicine and Odontology, University of the Basque Country, Leioa, Basque Country, Spain. .,Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Universidad Finis Terrae, Santiago, Chile.
| | - Avish P Sharma
- Griffith Sports Physiology and Performance, School of Allied Health Sciences, Griffith University, Gold Coast, QLD, Australia.,Triathlon Australia, Burleigh Heads, QLD, Australia
| | - Trent Stellingwerff
- Canadian Sport Institute-Pacific, Victoria, BC, Canada.,Department of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada
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16
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Dominelli PB, Sheel AW. Exercise-induced arterial hypoxemia; some answers, more questions. Appl Physiol Nutr Metab 2019; 44:571-579. [DOI: 10.1139/apnm-2018-0468] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Exercise-induced arterial hypoxemia (EIAH) is characterized by the decrease in arterial oxygen tension and oxyhemoglobin saturation during dynamic aerobic exercise. Since the time of the initial observations, our knowledge and understanding of EIAH has grown, but many unknowns remain. The purpose of this review is to provide an update on recent findings, highlight areas of disagreement, and identify where information is lacking. Specifically, this review will place emphasis on (i) the occurrence of EIAH during submaximal exercise, (ii) whether there are sex differences in the development and severity of EIAH, and (iii) unresolved questions and future directions.
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Affiliation(s)
- Paolo B. Dominelli
- Department of Anesthesiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - A. William Sheel
- School of Kinesiology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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17
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SHARMA AVISHP, SAUNDERS PHILOU, GARVICAN-LEWIS LAURAA, CLARK BRAD, GORE CHRISTOPHERJ, THOMPSON KEVING, PÉRIARD JULIEND. Normobaric Hypoxia Reduces V˙O2 at Different Intensities in Highly Trained Runners. Med Sci Sports Exerc 2019; 51:174-182. [DOI: 10.1249/mss.0000000000001745] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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18
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Williams KA, Bell K, Jacobs RA, Subudhi AW. Supplemental Oxygen Does Not Influence Self-selected Work Rate at Moderate Altitude. Med Sci Sports Exerc 2018; 51:575-581. [PMID: 30299413 DOI: 10.1249/mss.0000000000001801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION It is well known that supplemental oxygen can increase aerobic power output during high-intensity and/or maximal efforts at moderate altitude, yet the effects on self-selected work rate during lower-intensity, submaximal exercise are unknown. We reasoned that if the degree of arterial oxygen saturation (SaO2) influences teleoanticipatory regulation of power output, supplemental oxygen given at moderate altitude would increase average power output during exercise performed at self-selected work rates corresponding to RPE 9 (very light) and 13 (somewhat hard). METHODS Twenty-three subjects (17 males, 6 females) completed one familiarization [fraction of inspired O2 (FIO2) = 0.209] and two blinded, experimental trials (FIO2 = 0.209 and FIO2 = 0.267). In each trial, subjects self-regulated their work rate on a cycle ergometer to maintain RPE 9 for 5 min and RPE 13 for 10 min, before performing an incremental step test to exhaustion (25 W·min). Oxygen consumption (V˙O2) and SaO2 via pulse oximetry (SpO2) were continuously monitored. Subjects were asked to guess the experimental condition after each stage of the protocol. RESULTS Supplemental oxygen increased SpO2 throughout exercise (~4%; P < 0.001) and was associated with greater peak power output (4% ± 4%; P < 0.001) and V˙O2 (5% ± 10%; P = 0.010) during the incremental test, but did not increase average power output selected during exercise at RPE 9 (P = 0.235) or 13 (P = 0.992). Subjects were unable to perceive the difference in FIO2 at any stage (P > 0.14). CONCLUSIONS Small increases in inspired oxygen concentration at moderate altitude are imperceptible and do not appear to influence selection of submaximal work rates at RPE ≤ 13.
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Affiliation(s)
- Kirsten A Williams
- University of Colorado Colorado Springs, Department of Biology, Colorado Springs, CO
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19
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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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20
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Physiological Responses to Treadmill Running With Body Weight Support in Hypoxia Compared With Normoxia. J Sport Rehabil 2018; 27:224-229. [PMID: 28338405 DOI: 10.1123/jsr.2016-0210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
CONTEXT Anecdotal reports suggest elite sports clubs combine lower-body positive-pressure rehabilitation with a hypoxic stimulus to maintain or increase physiological and metabolic strain, which are reduced during lower-body positive pressure. However, the effects of hypoxia on cardiovascular and metabolic response during lower-body positive-pressure rehabilitation are unknown. OBJECTIVE Evaluate the use of normobaric hypoxia as a means to increase physiological strain during body-weight-supported (BWS) running. DESIGN Crossover study. SETTING Controlled laboratory. PARTICIPANTS Seven familiarized males (mean (SD): age, 20 (1) y; height, 1.77 (0.05) m; mass, 69.4 (5.1) kg; hemoglobin, 15.2 (0.8) g·dL-1) completed a normoxic and hypoxic (fraction of inspired oxygen [O2] = 0.14) trial, during which they ran at 8 km·h-1 on an AlterG™ treadmill with 0%, 30%, and 60% BWS in a randomized order for 10 minutes interspersed with 5 minutes of recovery. MAIN OUTCOME MEASURES Arterial O2 saturation, heart rate, O2 delivery, and measurements of metabolic strain via indirect calorimetry. RESULTS Hypoxic exercise reduced hemoglobin O2 saturation and elevated heart rate at each level of BWS compared with normoxia. However, the reduction in hemoglobin O2 saturation was attenuated at 60% BWS compared with 0% and 30%, and consequently, O2 delivery was better maintained at 60% BWS. CONCLUSION Hypoxia is a practically useful means of increasing physiological strain during BWS rehabilitation. In light of the maintenance of hemoglobin O2 saturation and O2 delivery at increasing levels of BWS, fixed hemoglobin saturations rather than a fixed altitude are recommended to maintain an aerobic stimulus.
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21
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Best A, Braun B. Using a novel data resource to explore heart rate during mountain and road running. Physiol Rep 2018; 5:5/8/e13256. [PMID: 28424267 PMCID: PMC5408286 DOI: 10.14814/phy2.13256] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 03/23/2017] [Accepted: 03/23/2017] [Indexed: 11/24/2022] Open
Abstract
Online, accessible performance and heart rate data from running competitions are posted publicly or semi‐publicly to social media. We tested the efficacy of one such data resource‐ Strava‐ as a tool in exercise physiology investigations by exploring heart rate differences in mountain racing and road racing running events. Heart rate and GPS pace data were gathered from Strava activities posted by 111 males aged 21–49, from two mountain races (Mt. Washington Road Race and Pike's Peak Ascent) and two road race distances (half marathon and marathon). Variables of interest included race finish time, average heart rate, time to complete the first half (by distance) of the race, time to complete the second half, average heart rate for both the first and second half, estimated maximal heart rate, and competitiveness (finish time as percentage of winning time). Mountain runners on average showed no change in heart rate in the second versus first half of the event, while road racers at the half marathon and marathon distances showed increased second‐half heart rate. Mountain runners slowed considerably more in the second half than road runners. Heart rate increases in road races were likely reflective of cardiac drift. Altitude and other demands specific to mountain racing may explain why this was not observed in mountain races. Strava presents enormous untapped opportunity for exercise physiology research, enabling initial inquiry into physiological questions that may then be followed by targeted laboratory studies.
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Affiliation(s)
- Andrew Best
- Department of Anthropology, University of Massachusetts, Amherst, Massachusetts
| | - Barry Braun
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
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22
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Botek M, Krejčí J, McKune A. Sex Differences in Autonomic Cardiac Control and Oxygen Saturation Response to Short-Term Normobaric Hypoxia and Following Recovery: Effect of Aerobic Fitness. Front Endocrinol (Lausanne) 2018; 9:697. [PMID: 30532736 PMCID: PMC6265316 DOI: 10.3389/fendo.2018.00697] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 11/05/2018] [Indexed: 01/06/2023] Open
Abstract
Introduction: The main aims of this study were to investigate autonomic nervous system (ANS) and arterial oxygen saturation (SpO2) responses to simulated altitude in males and females, and to determine the association between maximal oxygen uptake (VO2max) and these responses. Materials and Methods: Heart rate variability (HRV) and SpO2 were monitored in a resting supine position during Preliminary (6 min normoxia), Hypoxia (10 min, fraction of inspired oxygen (FiO2) of 9.6%, simulated altitude ~6,200 m) and Recovery (6 min normoxia) phases in 28 males (age 23.7 ± 1.7 years, normoxic VO2max 59.0 ± 7.8 ml.kg-1.min-1, body mass index (BMI) 24.2 ± 2.1 kg.m-2) and 30 females (age 23.8 ± 1.8 years, VO2max 45.1 ± 8.7 ml.kg-1.min-1, BMI 21.8 ± 3.0 kg.m-2). Spectral analysis of HRV quantified the ANS activity by means of low frequency (LF, 0.05-0.15 Hz) and high frequency (HF, 0.15-0.50 Hz) power, transformed by natural logarithm (Ln). Time domain analysis incorporated the square root of the mean of the squares of the successive differences (rMSSD). Results: There were no significant differences in SpO2 level during hypoxia between the males (71.9 ± 7.5%) and females (70.8 ± 7.1%). Vagally-related HRV variables (Ln HF and Ln rMSSD) exhibited no significant differences between sexes across each phase. However, while the sexes demonstrated similar Ln LF/HF values during the Preliminary phase, the males (0.5 ± 1.3) had a relatively higher (p = 0.001) sympathetic activity compared to females (-0.6 ± 1.4) during the Hypoxia phase. Oxygen desaturation during resting hypoxia was significantly correlated with VO2max in males (r = -0.45, p = 0.017) but not in females (r = 0.01, p = 0.952) and difference between regression lines were significant (p = 0.024). Conclusions: Despite similar oxygen desaturation levels, males exhibited a relatively higher sympathetic responses to hypoxia exposure compared with females. In addition, the SpO2 response to resting hypoxia exposure was related to maximal aerobic capacity in males but not females.
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Affiliation(s)
- Michal Botek
- Department of Natural Sciences in Kinanthropology, Faculty of Physical Culture, Palacký University Olomouc, Olomouc, Czechia
| | - Jakub Krejčí
- Department of Natural Sciences in Kinanthropology, Faculty of Physical Culture, Palacký University Olomouc, Olomouc, Czechia
- *Correspondence: Jakub Krejčí
| | - Andrew McKune
- Discipline of Sport and Exercise Science, School of Rehabilitation and Exercise Sciences, Research Institute for Sport and Exercise Science, University of Canberra, Canberra, ACT, Australia
- Discipline of Biokinetics, Exercise and Leisure Sciences, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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23
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Moraga FA, Osorio J, Calderón-Jofré R, Pedreros A. Hemoconcentration During Maximum Exercise in Miners with Chronic Intermittent Exposure to Hypobaric Hypoxia (3800 m). High Alt Med Biol 2017; 19:15-20. [PMID: 29035586 DOI: 10.1089/ham.2017.0011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Moraga, Fernando A., Jorge Osorio, Rodrigo Calderón-Jofré, and Andrés Pedreros. Hemoconcentration during maximum exercise in miners with chronic intermittent exposure to hypobaric hypoxia (3800 m). High Alt Med Biol. 19:15-20, 2018. OBJECTIVE To evaluate the effect of maximum exercise on hemoconcentration in miners with chronic intermittent hypobaric hypoxia (CIHH) at 3800 m. MATERIALS AND METHODS Sixteen miners with CIHH at high altitude (3800 m) were subjected to maximum exercise levels on a cycle ergometer, increasing exercise load by 50 W every 3 minutes at sea level and high altitude (3800 m). During exercise, arterial oxygen saturation and heart rate were measured. Blood samples were taken at each step to measure hemoglobin concentration and hematocrit. Arterial blood oxygen content was also calculated. RESULTS At sea level, a decrease in arterial oxygen saturation to 92.1% ± 2.5% was observed at 150 W and the hematocrit, hemoglobin concentration and oxygen content were not altered. At high altitude, arterial oxygen saturation decreased, reaching 88.2% ± 4.9% at 50 W and remained constant during the entire exercise protocol. Hemoglobin concentration and hematocrit increased reaching 16.4 ± 0.9 g/dL and 48.8% ± 1.6%, respectively, at 100 W and were maintained until recovery. Arterial oxygen content was constant during exercise and increased in the recovery period. CONCLUSION An increase in hemoglobin concentration during exercise compensates for the decline in arterial oxygen saturation, meanwhile arterial oxygen content remains constant.
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Affiliation(s)
- Fernando A Moraga
- 1 Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte , Coquimbo, Chile
| | - Jorge Osorio
- 2 Instituto de Estudios de la Salud , Universidad Arturo Prat, Iquique, Chile
| | - Rodrigo Calderón-Jofré
- 1 Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte , Coquimbo, Chile
| | - Andrés Pedreros
- 1 Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte , Coquimbo, Chile
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24
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Keramidas ME, Mekjavic IB, Eiken O. LunHab: interactive effects of a 10 day sustained exposure to hypoxia and bedrest on aerobic exercise capacity in male lowlanders. Exp Physiol 2017; 102:694-710. [DOI: 10.1113/ep086167] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/20/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Michail E. Keramidas
- Department of Environmental Physiology; Swedish Aerospace Physiology Center; School of Technology and Health; Royal Institute of Technology; Stockholm Sweden
| | - Igor B. Mekjavic
- Department of Automation; Biocybernetics and Robotics; Jozef Stefan Institute; Ljubljana Slovenia
- Department of Biomedical Physiology and Kinesiology; Simon Fraser University; Burnaby BC Canada
| | - Ola Eiken
- Department of Environmental Physiology; Swedish Aerospace Physiology Center; School of Technology and Health; Royal Institute of Technology; Stockholm Sweden
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Sweeting AJ, Billaut F, Varley MC, Rodriguez RF, Hopkins WG, Aughey RJ. Variations in Hypoxia Impairs Muscle Oxygenation and Performance during Simulated Team-Sport Running. Front Physiol 2017; 8:80. [PMID: 28239359 PMCID: PMC5301029 DOI: 10.3389/fphys.2017.00080] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/27/2017] [Indexed: 11/13/2022] Open
Abstract
Purpose: To quantify the effect of acute hypoxia on muscle oxygenation and power during simulated team-sport running. Methods: Seven individuals performed repeated and single sprint efforts, embedded in a simulated team-sport running protocol, on a non-motorized treadmill in normoxia (sea-level), and acute normobaric hypoxia (simulated altitudes of 2,000 and 3,000 m). Mean and peak power was quantified during all sprints and repeated sprints. Mean total work, heart rate, blood oxygen saturation, and quadriceps muscle deoxyhaemoglobin concentration (assessed via near-infrared spectroscopy) were measured over the entire protocol. A linear mixed model was used to estimate performance and physiological effects across each half of the protocol. Changes were expressed in standardized units for assessment of magnitude. Uncertainty in the changes was expressed as a 90% confidence interval and interpreted via non-clinical magnitude-based inference. Results: Mean total work was reduced at 2,000 m (-10%, 90% confidence limits ±6%) and 3,000 m (-15%, ±5%) compared with sea-level. Mean heart rate was reduced at 3,000 m compared with 2,000 m (-3, ±3 min-1) and sea-level (-3, ±3 min-1). Blood oxygen saturation was lower at 2,000 m (-8, ±3%) and 3,000 m (-15, ±2%) compared with sea-level. Sprint mean power across the entire protocol was reduced at 3,000 m compared with 2,000 m (-12%, ±3%) and sea-level (-14%, ±4%). In the second half of the protocol, sprint mean power was reduced at 3,000 m compared to 2,000 m (-6%, ±4%). Sprint mean peak power across the entire protocol was lowered at 2,000 m (-10%, ±6%) and 3,000 m (-16%, ±6%) compared with sea-level. During repeated sprints, mean peak power was lower at 2,000 m (-8%, ±7%) and 3,000 m (-8%, ±7%) compared with sea-level. In the second half of the protocol, repeated sprint mean power was reduced at 3,000 m compared to 2,000 m (-7%, ±5%) and sea-level (-9%, ±5%). Quadriceps muscle deoxyhaemoglobin concentration was lowered at 3,000 m compared to 2,000 m (-10, ±12%) and sea-level (-11, ±12%). Conclusions: Simulated team-sport running is impaired at 3,000 m compared to 2,000 m and sea-level, likely due to a higher muscle deoxygenation.
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Affiliation(s)
- Alice J Sweeting
- Institute of Sport, Exercise and Active Living, Victoria University Melbourne, VIC, Australia
| | - François Billaut
- Institute of Sport, Exercise and Active Living, Victoria UniversityMelbourne, VIC, Australia; Département de Kinesiology, Université LavalQuébec, QC, Canada
| | - Matthew C Varley
- Institute of Sport, Exercise and Active Living, Victoria University Melbourne, VIC, Australia
| | - Ramón F Rodriguez
- Institute of Sport, Exercise and Active Living, Victoria University Melbourne, VIC, Australia
| | - William G Hopkins
- Institute of Sport, Exercise and Active Living, Victoria University Melbourne, VIC, Australia
| | - Robert J Aughey
- Institute of Sport, Exercise and Active Living, Victoria University Melbourne, VIC, Australia
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Ramírez‐Vélez R, Palacios‐López A, Humberto Prieto‐Benavides D, Enrique Correa‐Bautista J, Izquierdo M, Alonso‐Martínez A, Lobelo F. Normative reference values for the 20 m shuttle-run test in a population-based sample of school-aged youth in Bogota, Colombia: the FUPRECOL study. Am J Hum Biol 2017; 29:e22902. [PMID: 27500986 PMCID: PMC5298048 DOI: 10.1002/ajhb.22902] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 06/20/2016] [Accepted: 07/23/2016] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVES Our aim was to determine the normative reference values of cardiorespiratory fitness (CRF) and to establish the proportion of subjects with low CRF suggestive of future cardio-metabolic risk. METHODS A total of 7244 children and adolescents attending public schools in Bogota, Colombia (55.7% girls; age range of 9-17.9 years) participated in this study. We expressed CRF performance as the nearest stage (minute) completed and the estimated peak oxygen consumption (V˙O2peak ). Smoothed percentile curves were calculated. In addition, we present the prevalence of low CRF after applying a correction factor to account for the impact of Bogota's altitude (2625 m over sea level) on CRF assessment, and we calculated the number of participants who fell below health-related FITNESSGRAM cut-points for low CRF. RESULTS Shuttles and V˙O2peak were higher in boys than in girls in all age groups. In boys, there were higher levels of performance with increasing age, with most gains between the ages of 13 and 17. The proportion of subjects with a low CRF, suggestive of future cardio-metabolic risk (health risk FITNESSGRAM category) was 31.5% (28.2% for boys and 34.1% for girls; X2 P = .001). After applying a 1.11 altitude correction factor, the overall prevalence of low CRF was 11.5% (9.6% for boys and 13.1% for girls; X2 P = .001). CONCLUSIONS Our results provide sex- and age-specific normative reference standards for the 20 m shuttle-run test and estimated V˙O2peak values in a large, population-based sample of schoolchildren from a large Latin-American city at high altitude.
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Affiliation(s)
- Robinson Ramírez‐Vélez
- Centro de Estudios en Medición de la Actividad Física (CEMA), Escuela de Medicina y Ciencias de la Salud, Universidad del RosarioBogotáD.CColombia
| | - Adalberto Palacios‐López
- Centro de Estudios en Medición de la Actividad Física (CEMA), Escuela de Medicina y Ciencias de la Salud, Universidad del RosarioBogotáD.CColombia
| | - Daniel Humberto Prieto‐Benavides
- Centro de Estudios en Medición de la Actividad Física (CEMA), Escuela de Medicina y Ciencias de la Salud, Universidad del RosarioBogotáD.CColombia
| | - Jorge Enrique Correa‐Bautista
- Centro de Estudios en Medición de la Actividad Física (CEMA), Escuela de Medicina y Ciencias de la Salud, Universidad del RosarioBogotáD.CColombia
| | - Mikel Izquierdo
- Grupo GICAEDS, Facultad de Cultura Física, Deporte y Recreación, Universidad Santo TomásBogotáD.CColombia
- Department of Health SciencesPublic University of NavarraNavarraSpain
| | | | - Felipe Lobelo
- Hubert Department of Global HealthRollins School of Public Health, Emory UniversityAtlantaGeorgia
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Beidleman BA, Fulco CS, Buller MJ, Andrew SP, Staab JE, Muza SR. Quantitative Model of Sustained Physical Task Duration at Varying Altitudes. Med Sci Sports Exerc 2016; 48:323-30. [PMID: 26339725 DOI: 10.1249/mss.0000000000000768] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE The objective of this study is to develop a quantitative model that can be used before ascent to altitude (ALT) to predict how much longer a sustained physical task would take for unacclimatized individuals in the early hours of exposure. METHODS Using multiple linear regression, we analyzed time-trial (TT) performance on 95 unacclimatized men (n = 83) and women (n = 12) at sea level (SL) and at an ALT ranging from 2500 to 4300 m. The TT was initiated within 4 h of ascent to ALT. The independent variables known before ascent were as follows: ALT, age, height, weight, sex, SL peak oxygen uptake, SL task duration time, and body mass index (BMI) classification (normal weight vs overweight). The dependent variable was the percent increase in TT duration from SL to ALT. RESULTS The most significant factor in the model was ALT (P = 0.0001), followed by BMI classification (P = 0.0009) and the interaction between BMI classification and ALT (P = 0.003). The model is as follows: percent increase in TT duration = [100 + e(-1.517+1.323 (ALT)+3.124 (BMI class)-0.769 (ALT) (BMI class)]. The percent increase in TT duration in overweight individuals was 129% greater than for normal-weight individuals at 3000 m. However, as ALT increased beyond 3000 m, the disparity between groups decreased until 4050 m where the percent increase in TT duration became greater for normal-weight individuals. CONCLUSIONS This model provides the first quantitative estimates of the percent increase in sustained physical task duration during initial exposure to a wide range of elevations. Because only two easily obtainable factors are required as inputs for the model (ALT and BMI classification), this model can be used by many unacclimatized individuals to better plan their activities at ALT.
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Affiliation(s)
- Beth A Beidleman
- 1Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, Natick, MA; and 2Biophysics and Biomedical Modelling Division, United States Army Research Institute of Environmental Medicine, Natick, MA
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Exercise-Induced Hypoxaemia Developed at Sea-Level Influences Responses to Exercise at Moderate Altitude. PLoS One 2016; 11:e0161819. [PMID: 27583364 PMCID: PMC5008680 DOI: 10.1371/journal.pone.0161819] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 08/12/2016] [Indexed: 11/20/2022] Open
Abstract
Purpose The aim of this study was to investigate the impact of exercise-induced hypoxaemia (EIH) developed at sea-level on exercise responses at moderate acute altitude. Methods Twenty three subjects divided in three groups of individuals: highly trained with EIH (n = 7); highly trained without EIH (n = 8) and untrained participants (n = 8) performed two maximal incremental tests at sea-level and at 2,150 m. Haemoglobin O2 saturation (SpO2), heart rate, oxygen uptake (VO2) and several ventilatory parameters were measured continuously during the tests. Results EIH athletes had a drop in SpO2 from 99 ± 0.8% to 91 ± 1.2% from rest to maximal exercise at sea-level, while the other groups did not exhibit a similar decrease. EIH athletes had a greater decrease in VO2max at altitude compared to non-EIH and untrained groups (-22 ± 7.9%, -16 ± 5.3% and -13 ± 9.4%, respectively). At altitude, non-EIH athletes had a similar drop in SpO2 as EIH athletes (13 ± 0.8%) but greater than untrained participants (6 ± 1.0%). EIH athletes showed greater decrease in maximal heart rate than non-EIH athletes at altitude (8 ± 3.3 bpm and 5 ± 2.9 bpm, respectively). Conclusion EIH athletes demonstrated specific cardiorespiratory response to exercise at moderate altitude compared to non-EIH athletes with a higher decrease in VO2max certainly due to the lower ventilator and HRmax responses. Thus EIH phenomenon developed at sea-level negatively impact performance and cardiorespiratory responses at acute moderate altitude despite no potentiated O2 desaturation.
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Fan JL, Kayser B. Fatigue and Exhaustion in Hypoxia: The Role of Cerebral Oxygenation. High Alt Med Biol 2016; 17:72-84. [DOI: 10.1089/ham.2016.0034] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- Jui-Lin Fan
- Centre for Translational Physiology, University of Otago, Wellington, New Zealand
- Department of Surgery & Anaesthesia, University of Otago, Wellington, New Zealand
| | - Bengt Kayser
- Institute of Sports Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
- Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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Chapman RF, Karlsen T, Ge RL, Stray-Gundersen J, Levine BD. Living altitude influences endurance exercise performance change over time at altitude. J Appl Physiol (1985) 2016; 120:1151-8. [DOI: 10.1152/japplphysiol.00909.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 03/04/2016] [Indexed: 11/22/2022] Open
Abstract
For sea level based endurance athletes who compete at low and moderate altitudes, adequate time for acclimatization to altitude can mitigate performance declines. We asked whether it is better for the acclimatizing athlete to live at the specific altitude of competition or at a higher altitude, perhaps for an increased rate of physiological adaptation. After 4 wk of supervised sea level training and testing, 48 collegiate distance runners (32 men, 16 women) were randomly assigned to one of four living altitudes (1,780, 2,085, 2,454, or 2,800 m) where they resided for 4 wk. Daily training for all subjects was completed at a common altitude from 1,250 to 3,000 m. Subjects completed 3,000-m performance trials on the track at sea level, 28 and 6 days before departure, and at 1,780 m on days 5, 12, 19, and 26 of the altitude camp. Groups living at 2,454 and 2,800 m had a significantly larger slowing of performance vs. the 1,780-m group on day 5 at altitude. The 1,780-m group showed no significant change in performance across the 26 days at altitude, while the groups living at 2,085, 2,454, and 2,800 m showed improvements in performance from day 5 to day 19 at altitude but no further improvement at day 26. The data suggest that an endurance athlete competing acutely at 1,780 m should live at the altitude of the competition and not higher. Living ∼300-1,000 m higher than the competition altitude, acute altitude performance may be significantly worse and may require up to 19 days of acclimatization to minimize performance decrements.
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Affiliation(s)
| | - Trine Karlsen
- K. G. Jebsen Center of Exercise in Medicine, Department of Circulation and Medical Imaging, Norweigan University of Science and Technology, Trondheim, Norway
| | - R.-L. Ge
- Research Center for High Altitude Medicine, Qinghai University, Qinghai, China
| | | | - Benjamin D. Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, The University of Texas Southwestern Medical Center, Dallas, Texas
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Ensemble Input of Group III/IV Muscle Afferents to CNS: A Limiting Factor of Central Motor Drive During Endurance Exercise from Normoxia to Moderate Hypoxia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 903:325-42. [PMID: 27343106 DOI: 10.1007/978-1-4899-7678-9_22] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We recently hypothesized that across the range of normoxia to severe hypoxia the major determinant of central motor drive (CMD) during endurance exercise switches from a predominantly peripheral origin to a hypoxic-sensitive central component of fatigue. We found that peripheral locomotor muscle fatigue (pLMF) is the prevailing factor limiting central motor drive and therefore exercise performance from normoxia to moderate hypoxia (SaO2 > 75 %). In these levels of arterial hypoxemia, the development of pLMF is confined to a certain limit which varies between humans-pLMF does not develop to this limit in more severe hypoxia (SaO2 < 70 %) and exercise is prematurely terminated presumably to protect the brain from insufficient O2 supply. Based on the observations from normoxia to moderate hypoxia, we outlined a model suggesting that group III/IV muscle afferents impose inhibitory influences on the determination of CMD of working humans during high-intensity endurance exercise with the purpose to regulate and restrict the level of exercise-induced pLMF to an "individual critical threshold." To experimentally test this model, we pharmacologically blocked somatosensory pathways originating in the working limbs during cycling exercise in normoxia. After initial difficulties with a local anesthetic (epidural lidocaine, L3-L4) and associated loss of locomotor muscle strength we switched to an intrathecally applied opioid analgesic (fentanyl, L3-L4). These experiments were the first ever to selectively block locomotor muscle afferents during high-intensity cycling exercise without affecting maximal locomotor muscle strength. In the absence of opioid-mediated neural feedback from the working limbs, CMD was increased and end-exercise pLMF substantially exceeded, for the first time, the individual critical threshold of peripheral fatigue. The outcome of these studies confirm our hypothesis claiming that afferent feedback inhibits CMD and restricts the development of pLMF to an individual critical threshold as observed from normoxia up to moderate hypoxia.
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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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Garvican-Lewis LA, Clark B, Martin DT, Schumacher YO, McDonald W, Stephens B, Ma F, Thompson KG, Gore CJ, Menaspà P. Impact of Altitude on Power Output during Cycling Stage Racing. PLoS One 2015; 10:e0143028. [PMID: 26629912 PMCID: PMC4668098 DOI: 10.1371/journal.pone.0143028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 10/29/2015] [Indexed: 11/18/2022] Open
Abstract
PURPOSE The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour. METHODS Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP) and corresponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000 m (<1000 m, 1000-2000, 2000-3000 and >3000 m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin. RESULTS Power output was similar between the laboratory power-profile and the race simulation, however MMPs for 5-600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001) while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p < 0.001) during racing at moderate-high altitude compared with the race simulation near sea-level. CONCLUSION A reduction in oxygen availability as altitude increases leads to attenuation of cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes.
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Affiliation(s)
- Laura A Garvican-Lewis
- Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia
- Physiology, Australian Institute of Sport, Canberra, Australia
- * E-mail:
| | - Bradley Clark
- Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia
- Physiology, Australian Institute of Sport, Canberra, Australia
| | - David T. Martin
- Physiology, Australian Institute of Sport, Canberra, Australia
| | | | | | | | - Fuhai Ma
- Qinghai Institute of Sport Science, Duoba, China
| | - Kevin G. Thompson
- Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia
| | - Christopher J. Gore
- Physiology, Australian Institute of Sport, Canberra, Australia
- Exercise Physiology Laboratory, Flinders University, Adelaide, Australia
| | - Paolo Menaspà
- Physiology, Australian Institute of Sport, Canberra, Australia
- Edith Cowan University, Perth, Australia
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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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Lundby C, Robach P. Performance Enhancement: What Are the Physiological Limits? Physiology (Bethesda) 2015; 30:282-92. [DOI: 10.1152/physiol.00052.2014] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our objective is to highlight some key physiological determinants of endurance exercise performance and to discuss how these can be further improved. V̇o2max remains remarkably stable throughout an athletic career. By contrast, exercise economy, lactate threshold, and critical power may be improved in world-class athletes by specific exercise training regimes and/or with more years of training.
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Affiliation(s)
- C. Lundby
- Zürich Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zürich, Switzerland
- Food & Nutrition & Sport Science, Gothenburg University, Gothenburg, Sweden; and
| | - P. Robach
- Ecole Nationale des Sports de Montagne, Site de l'Ecole Nationale de Ski et d'Alpinisme, Chamonix, France
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Abstract
We address adaptive vs. maladaptive responses to hypoxemia in healthy humans and hypoxic-tolerant species during wakefulness, sleep, and exercise. Types of hypoxemia discussed include short-term and life-long residence at high altitudes, the intermittent hypoxemia attending sleep apnea, or training regimens prescribed for endurance athletes. We propose that hypoxia presents an insult to O2 transport, which is poorly tolerated in most humans because of the physiological cost.
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Affiliation(s)
- Jerome A Dempsey
- John Rankin Laboratory of Pulmonary Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin; Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin; and
| | - Barbara J Morgan
- John Rankin Laboratory of Pulmonary Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin; Department of Orthopedics and Rehabilitation, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
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Kiyamu M, León-Velarde F, Rivera-Chira M, Elías G, Brutsaert TD. Developmental Effects Determine Submaximal Arterial Oxygen Saturation in Peruvian Quechua. High Alt Med Biol 2015; 16:138-46. [PMID: 25977978 DOI: 10.1089/ham.2014.1126] [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] [Indexed: 11/13/2022] Open
Abstract
Kiyamu, Melisa, Fabiola León-Velarde, María Rivera-Chira, Gianpietro Elías, and Tom D. Brutsaert. Developmental effects determine submaximal arterial oxygen saturation in Peruvian Quechua. High Alt Med Biol 16, 138-146, 2015.--Andean high altitude natives show higher arterial oxygen saturation (Sao(2)) during exercise in hypoxia, compared to acclimatized sojourners. In order to evaluate the effects of life-long exposure to high altitude on Sao(2), we studied two groups of well-matched, self-identified Peruvian Quechua natives who differed in their developmental exposure to hypoxia before and after a 2-month training period. Male and female volunteers (18-35 years) were recruited in Lima, Peru (150 m). The two groups were: a) Individuals who were born and raised at sea-level (BSL, n=34) and b) Individuals who were born and raised at high altitude (BHA, n=32), but who migrated to sea-level as adults (>16 years old). Exercise testing was conducted using a submaximal exercise protocol in normobaric hypoxia in Lima (BP=750 mmHg, Fio(2)=0.12), in order to measure Sao(2) (%), ventilation (VE L/min) and oxygen consumption (Vo(2), L/min). Repeated-measures ANOVA, controlling for VE/VO(2) (L/min) and sex during the submaximal protocol showed that BHA maintained higher Sao(2) (%) compared to BSL at all workloads before (p=0.005) and after training (p=0.017). As expected, both groups showed a decrease in Sao(2) (%) (p<0.001), as workload increased. Resting Sao(2) levels were not found to be different between groups. The results suggest that developmental exposure to altitude contributes to the maintenance of higher Sao(2) levels during submaximal exercise at hypoxia.
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Affiliation(s)
- Melisa Kiyamu
- 1 Departamento de Ciencias Biológicas y Fisiológicas, Universidad Peruana Cayetano Heredia , Urb. San Martín de Porres, Peru
| | - Fabiola León-Velarde
- 1 Departamento de Ciencias Biológicas y Fisiológicas, Universidad Peruana Cayetano Heredia , Urb. San Martín de Porres, Peru
| | - María Rivera-Chira
- 1 Departamento de Ciencias Biológicas y Fisiológicas, Universidad Peruana Cayetano Heredia , Urb. San Martín de Porres, Peru
| | - Gianpietro Elías
- 1 Departamento de Ciencias Biológicas y Fisiológicas, Universidad Peruana Cayetano Heredia , Urb. San Martín de Porres, Peru
| | - Tom D Brutsaert
- 2 Department of Exercise Science, Syracuse University , Syracuse, New York
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Endurance exercise performance in acute hypoxia is influenced by expiratory flow limitation. Eur J Appl Physiol 2015; 115:1653-63. [DOI: 10.1007/s00421-015-3145-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 02/25/2015] [Indexed: 10/23/2022]
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Abstract
AbstractPurpose. Recreational cross-country skiers can benefit from a performance diagnostic when planning a training program. The aim of this study was to establish a simple test protocol to measure endurance capacity and provide training recommendations. Methods. The relationship between endurance performance and cross-country skiing technique was assessed using two tests. First, a lactate threshold test whereby running speed was determined on a treadmill at 4 mmol/l blood lactate concentration. Second, participants completed a variation of the Cooper test using skating technique on flat terrain to determine the distance covered in 12 min and maximum heart rate. Results. There was a correlative (r = 0.18 respectivelly R2 = 0.43) relationship of between the distance covered in the Cooper test and treadmill running speed at 4 mmol/l blood lactate concentration. Conclusions. The two tests allow recreational athletes to rank themselves with regards to their endurance capacity within a population. The relationship between distance covered and maximum heart rate can indicate whether future training should focus on technical or physical improvement.
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Kiyamu M, Rivera-Chira M, Brutsaert TD. Aerobic capacity of Peruvian Quechua: a test of the developmental adaptation hypothesis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2014; 156:363-73. [PMID: 25385548 DOI: 10.1002/ajpa.22655] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 10/22/2014] [Indexed: 12/31/2022]
Abstract
High altitude natives are reported to have outstanding work capacity in spite of the challenge of oxygen transport and delivery in hypoxia. To evaluate the developmental effect of lifelong exposure to hypoxia on aerobic capacity, VO2peak was measured on two groups of Peruvian Quechua subjects (18-35 years), who differed in their developmental exposure to altitude. Male and female volunteers were recruited in Lima, Peru (150 m), and were divided in two groups, based on their developmental exposure to hypoxia, those: a) Born at sea-level individuals (BSL), with no developmental exposure to hypoxia (n = 34) and b) Born at high-altitude individuals (BHA) with full developmental exposure to hypoxia (n = 32), but who migrated to sea-level as adults (>16-years-old). Tests were conducted both in normoxia (BP = 750 mm Hg) and normobaric hypoxia at sea-level (BP = 750 mm Hg, FiO2 = 0.12, equivalent to 4,449 m), after a 2-month training period (in order to control for initial differences in physical fitness) at sea-level. BHA had a significantly higher VO2peak at hypoxia (40.31 ± 1.0 ml/min/kg) as compared to BSL (35.78 ± 0.96 ml/min/kg, P = 0.001), adjusting for sex. The decrease of VO2peak at HA relative to SL (ΔVO2peak ) was not different between groups, controlling for baseline levels (VO2peak at sea-level) and sex (BHA = 0.35 ± 0.04 l/min, BSL = 0.44 ± 0.04 l/min; P = 0.12). Forced vital capacity (controlling for height) and the residuals of VO2peak (controlling for weight) had a significant association in the BHA group only (r = 0.155; P = 0.031). In sum, results indicate that developmental exposure to altitude constitutes an important factor to determine superior exercise performance.
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Affiliation(s)
- Melisa Kiyamu
- Departamento de Ciencias Biológicas y Fisiológicas, Universidad Peruana Cayetano Heredia, Lima, Perú
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Garvican-Lewis LA, Schumacher YO, Clark SA, Christian R, Menaspà P, Plowman J, Stephens B, Qi J, Fan R, He Y, Martin DT, Thompson KG, Gore CJ, Ma F. Stage racing at altitude induces hemodilution despite an increase in hemoglobin mass. J Appl Physiol (1985) 2014; 117:463-72. [DOI: 10.1152/japplphysiol.00242.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Plasma volume (PV) can be modulated by altitude exposure (decrease) and periods of intense exercise (increase). Cycle racing at altitude combines both stimuli, although presently no data exist to document which is dominant. Hemoglobin mass (Hbmass), hemoglobin concentration ([Hb]), and percent reticulocytes (%Retics) of altitude (ALT; n = 9) and sea-level (SL; n = 9) residents were measured during a 14-day cycling race, held at 1,146–4120 m, as well as during a simulated tour near sea level (SIM; n = 12). Hbmass was assessed before and on days 9 and 14 of racing. Venous blood was collected on days 0, 3, 6, 10, and 14. PV was calculated from Hbmass and [Hb]. A repeated-measures ANOVA was used to assess the impact of racing at altitude over time, within and between groups. [Hb] decreased significantly in all groups over time ( P < 0.0001) with decreases evident on the third day of racing. %Retics increased significantly in SL only ( P < 0.0001), with SL values elevated at day 6 compared with prerace ( P = 0.02), but were suppressed by the end of the race ( P = 0.0002). Hbmass significantly increased in SL after 9 ( P = 0.0001) and 14 ( P = 0.008) days of racing and was lower at the end of the race than midrace ( P = 0.018). PV increased in all groups ( P < 0.0001). Multiday cycle racing at altitude induces hemodilution of a similar magnitude to that observed during SL racing and occurs in nonacclimatized SL residents, despite an altitude-induced increase in Hbmass. Osmotic regulatory mechanisms associated with intense exercise appear to supersede acute enhancement of oxygen delivery at altitude.
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Affiliation(s)
- Laura A. Garvican-Lewis
- Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia
- Physiology, Australian Institute of Sport, Canberra, Australia
| | | | - Sally A. Clark
- Physiology, Australian Institute of Sport, Canberra, Australia
| | - Ryan Christian
- Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - Paolo Menaspà
- Physiology, Australian Institute of Sport, Canberra, Australia
- Edith Cowan University, Perth, Australia; and
| | - Jamie Plowman
- Physiology, Australian Institute of Sport, Canberra, Australia
| | - Brian Stephens
- Physiology, Australian Institute of Sport, Canberra, Australia
| | - Jiliang Qi
- Qinghai Institute of Sports Science, Duoba, China
| | - Rongyun Fan
- Qinghai Institute of Sports Science, Duoba, China
| | - Yingying He
- Qinghai Institute of Sports Science, Duoba, China
| | - David T. Martin
- Physiology, Australian Institute of Sport, Canberra, Australia
| | - Kevin G. Thompson
- Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia
| | | | - Fuhai Ma
- Qinghai Institute of Sports Science, Duoba, China
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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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Gallagher CA, Willems MET, Lewis MP, Myers SD. Effect of acute normobaric hypoxia on the ventilatory threshold. Eur J Appl Physiol 2014; 114:1555-62. [DOI: 10.1007/s00421-014-2882-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 03/31/2014] [Indexed: 11/28/2022]
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Cerebral oxygenation during the Richalet hypoxia sensitivity test and cycling time-trial performance in severe hypoxia. Eur J Appl Physiol 2014; 114:1037-48. [DOI: 10.1007/s00421-014-2835-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 01/25/2014] [Indexed: 02/03/2023]
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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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Aughey RJ, Hammond K, Varley MC, Schmidt WF, Bourdon PC, Buchheit M, Simpson B, Garvican-Lewis LA, Kley M, Soria R, Sargent C, Roach GD, Claros JCJ, Wachsmuth N, Gore CJ. Soccer activity profile of altitude versus sea-level natives during acclimatisation to 3600 m (ISA3600). Br J Sports Med 2013; 47 Suppl 1:i107-13. [PMID: 24282196 PMCID: PMC3903145 DOI: 10.1136/bjsports-2013-092776] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2013] [Indexed: 11/15/2022]
Abstract
OBJECTIVES We investigated the effect of high altitude on the match activity profile of elite youth high altitude and sea level residents. METHODS Twenty Sea Level (Australian) and 19 Altitude-resident (Bolivian) soccer players played five games, two near sea level (430 m) and three in La Paz (3600 m). Match activity profile was quantified via global positioning system with the peak 5 min period for distance ((D₅(peak)) and high velocity running (>4.17 m/s, HIVR₅(peak)); as well as the 5 min period immediately subsequent to the peak for both distance (D₅(sub)) and high-velocity running (HIVR₅(sub)) identified using a rolling 5 min epoch. The games at 3600 m were compared with the average of the two near sea-level games. RESULTS The total distance per minute was reduced by a small magnitude in the first match at altitude in both teams, without any change in low-velocity running. There were variable changes in HiVR, D₅(peak) and HiVR₅(peak) from match to match for each team. There were within-team reductions in D₅(peak) in each game at altitude compared with those at near sea level, and this reduction was greater by a small magnitude in Australians than Bolivians in game 4. The effect of altitude on HiVR₅(peak) was moderately lower in Australians compared with Bolivians in game 3. There was no clear difference in the effect of altitude on maximal accelerations between teams. CONCLUSIONS High altitude reduces the distance covered by elite youth soccer players during matches. Neither 13 days of acclimatisation nor lifelong residence at high altitude protects against detrimental effects of altitude on match activity profile.
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Affiliation(s)
- Robert J Aughey
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Australia
- Western Bulldogs Football Club, Melbourne, Australia
| | - Kristal Hammond
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Australia
| | - Matthew C Varley
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Australia
| | - Walter F Schmidt
- Department of Sports Medicine/Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | | | | | - Ben Simpson
- ASPIRE Academy for Sports Excellence, Doha, Qatar
| | - Laura A Garvican-Lewis
- National Institute of Sports Studies, University of Canberra, Canberra, Australia
- Department of Physiology, Australian Institute of Sport, Canberra, Australia
| | - Marlen Kley
- Department of Sports Medicine/Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | - Rudy Soria
- Facultad de Medicina, Instituto Boliviano de Biología de Altura (IBBA), Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Charli Sargent
- Appleton Institute, Central Queensland University, Adelaide, Australia
| | - Gregory D Roach
- Appleton Institute, Central Queensland University, Adelaide, Australia
| | - Jesus C Jimenez Claros
- Facultad de Medicina, Instituto Boliviano de Biología de Altura (IBBA), Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Nadine Wachsmuth
- Department of Sports Medicine/Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | - Christopher J Gore
- Department of Physiology, Australian Institute of Sport, Canberra, Australia
- Exercise Physiology Laboratory, Flinders University, Adelaide, Australia
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Verges S, Rupp T, Jubeau M, Wuyam B, Esteve F, Levy P, Perrey S, Millet GY. Cerebral perturbations during exercise in hypoxia. Am J Physiol Regul Integr Comp Physiol 2012; 302:R903-16. [DOI: 10.1152/ajpregu.00555.2011] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reduction of aerobic exercise performance observed under hypoxic conditions is mainly attributed to altered muscle metabolism due to impaired O2 delivery. It has been recently proposed that hypoxia-induced cerebral perturbations may also contribute to exercise performance limitation. A significant reduction in cerebral oxygenation during whole body exercise has been reported in hypoxia compared with normoxia, while changes in cerebral perfusion may depend on the brain region, the level of arterial oxygenation and hyperventilation induced alterations in arterial CO2. With the use of transcranial magnetic stimulation, inconsistent changes in cortical excitability have been reported in hypoxia, whereas a greater impairment in maximal voluntary activation following a fatiguing exercise has been suggested when arterial O2 content is reduced. Electromyographic recordings during exercise showed an accelerated rise in central motor drive in hypoxia, probably to compensate for greater muscle contractile fatigue. This accelerated development of muscle fatigue in moderate hypoxia may be responsible for increased inhibitory afferent signals to the central nervous system leading to impaired central drive. In severe hypoxia (arterial O2 saturation <70–75%), cerebral hypoxia per se may become an important contributor to impaired performance and reduced motor drive during prolonged exercise. This review examines the effects of acute and chronic reduction in arterial O2 (and CO2) on cerebral blood flow and cerebral oxygenation, neuronal function, and central drive to the muscles. Direct and indirect influences of arterial deoxygenation on central command are separated. Methodological concerns as well as future research avenues are also considered.
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Affiliation(s)
- Samuel Verges
- INSERM U1042, Grenoble
- HP2 laboratory, Joseph Fourier University, Grenoble
- Exercise Research Unit, Grenoble University Hospital, Grenoble
| | - Thomas Rupp
- INSERM U1042, Grenoble
- HP2 laboratory, Joseph Fourier University, Grenoble
| | | | - Bernard Wuyam
- INSERM U1042, Grenoble
- HP2 laboratory, Joseph Fourier University, Grenoble
- Exercise Research Unit, Grenoble University Hospital, Grenoble
| | - François Esteve
- Exercise Research Unit, Grenoble University Hospital, Grenoble
- INSERM U836/team 6, Grenoble Institute of Neurosciences, Grenoble
| | - Patrick Levy
- INSERM U1042, Grenoble
- HP2 laboratory, Joseph Fourier University, Grenoble
- Exercise Research Unit, Grenoble University Hospital, Grenoble
| | - Stéphane Perrey
- Movement To Health (M2H), Montpellier-1 University, Euromov, Montpellier; and
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Chapman RF, Stager JM, Tanner DA, Stray-Gundersen J, Levine BD. Impairment of 3000-m run time at altitude is influenced by arterial oxyhemoglobin saturation. Med Sci Sports Exerc 2012; 43:1649-56. [PMID: 21311361 DOI: 10.1249/mss.0b013e318211bf45] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UNLABELLED The decline in maximal oxygen uptake (ΔVO(2)max) with acute exposure to moderate altitude is dependent on the ability to maintain arterial oxyhemoglobin saturation (SaO2). PURPOSE This study examined if factors related to ΔVO(2)max at altitude are also related to the decline in race performance of elite athletes at altitude. METHODS Twenty-seven elite distance runners (18 men and 9 women, VO(2)max = 71.8 ± 7.2 mL·kg(-1)·min(-1)) performed a treadmill exercise at a constant speed that simulated their 3000-m race pace, both in normoxia and in 16.3% O2 (∼2100 m). Separate 3000-m time trials were completed at sea level (18 h before altitude exposure) and at 2100 m (48 h after arrival at altitude). Statistical significance was set at P ≤ 0.05. RESULTS Group 3000-m performance was significantly slower at altitude versus sea level (48.5 ± 12.7 s), and the declines were significant in men (48.4 ± 14.6 s) and women (48.6 ± 8.9 s). Athletes grouped by low SaO2 during race pace in normoxia (SaO2 < 91%, n = 7) had a significantly larger ΔVO(2) in hypoxia (-9.2 ± 2.1 mL·kg(-1)·min(-1)) and Δ3000-m time at altitude (54.0 ± 13.7 s) compared with athletes with high SaO2 in normoxia (SaO2 > 93%, n = 7, ΔVO(2) = -3.5 ± 2.0 mL·kg(-1)·min(-1), Δ3000-m time = 38.9 ± 9.7 s). For all athletes, SaO2 during normoxic race pace running was significantly correlated with both ΔVO(2) (r = -0.68) and Δ3000-m time (r = -0.38). CONCLUSIONS These results indicate that the degree of arterial oxyhemoglobin desaturation, already known to influence ΔVO(2)max at altitude, also contributes to the magnitude of decline in race performance at altitude.
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Affiliation(s)
- Robert F Chapman
- Human Performance Laboratory, Department of Kinesiology, Indiana University, Bloomington, IN, USA.
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Brochu P, Brodeur J, Krishnan K. Derivation of physiological inhalation rates in children, adults, and elderly based on nighttime and daytime respiratory parameters. Inhal Toxicol 2011; 23:74-94. [DOI: 10.3109/08958378.2010.543439] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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