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Allsopp GL, Britto FA, Wright CR, Deldicque L. The Effects of Normobaric Hypoxia on the Acute Physiological Responses to Resistance Training: A Narrative Review. J Strength Cond Res 2024:00124278-990000000-00519. [PMID: 39178049 DOI: 10.1519/jsc.0000000000004909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2024]
Abstract
ABSTRACT Allsopp, GL, Britto, FA, Wright, CR, and Deldicque, L. The effects of normobaric hypoxia on the acute physiological responses to resistance training: a narrative review. J Strength Cond Res XX(X): 000-000, 2024-Athletes have used altitude training for many years as a strategy to improve endurance performance. The use of resistance training in simulated altitude (normobaric hypoxia) is a growing strategy that aims to improve the hypertrophy and strength adaptations to training. An increasing breadth of research has characterized the acute physiological responses to resistance training in hypoxia, often with the goal to elucidate the mechanisms by which hypoxia may improve the training adaptations. There is currently no consensus on the overall effectiveness of hypoxic resistance training for strength and hypertrophy adaptations, nor the underlying biochemical pathways involved. There are, however, numerous interesting physiological responses that are amplified by performing resistance training in hypoxia. These include potential changes to the energy system contribution to exercise and alterations to the level of metabolic stress, hormone and cytokine production, autonomic regulation, and other hypoxia-induced cellular pathways. This review describes the foundational exercise physiology underpinning the acute responses to resistance training in normobaric hypoxia, potential applications to clinical populations, including training considerations for athletic populations. The review also presents a summary of the ideal training parameters to promote metabolic stress and associated training adaptations. There are currently many gaps in our understanding of the physiological responses to hypoxic resistance training, partly caused by the infancy of the research field and diversity of hypoxic and training parameters.
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Affiliation(s)
- Giselle L Allsopp
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Victoria, Australia
| | | | - Craig R Wright
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Victoria, Australia
| | - Louise Deldicque
- Institute of Neuroscience, UC Louvain, Louvain-la-Neuve, Belgium
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Isakovich R, Cates VC, Pentz BA, Bird JD, Vanden Berg ER, de Freitas EM, Nysten CE, Leacy JK, O'Halloran KD, Brutsaert TD, Sherpa MT, Day TA. Using modified Fenn diagrams to assess ventilatory acclimatization during ascent to high altitude: Effect of acetazolamide. Exp Physiol 2024; 109:1080-1098. [PMID: 38747161 PMCID: PMC11215491 DOI: 10.1113/ep091748] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/12/2024] [Indexed: 07/02/2024]
Abstract
High altitude (HA) ascent imposes systemic hypoxia and associated risk of acute mountain sickness. Acute hypoxia elicits a hypoxic ventilatory response (HVR), which is augmented with chronic HA exposure (i.e., ventilatory acclimatization; VA). However, laboratory-based HVR tests lack portability and feasibility in field studies. As an alternative, we aimed to characterize area under the curve (AUC) calculations on Fenn diagrams, modified by plotting portable measurements of end-tidal carbon dioxide (P ETC O 2 ${P_{{\mathrm{ETC}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ) against peripheral oxygen saturation (S p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ) to characterize and quantify VA during incremental ascent to HA (n = 46). Secondarily, these participants were compared with a separate group following the identical ascent profile whilst self-administering a prophylactic oral dose of acetazolamide (Az; 125 mg BID; n = 20) during ascent. First, morningP ETC O 2 ${P_{{\mathrm{ETC}}{{\mathrm{O}}_{\mathrm{2}}}}}$ andS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ measurements were collected on 46 acetazolamide-free (NAz) lowland participants during an incremental ascent over 10 days to 5160 m in the Nepal Himalaya. AUC was calculated from individually constructed Fenn diagrams, with a trichotomized split on ranked values characterizing the smallest, medium, and largest magnitudes of AUC, representing high (n = 15), moderate (n = 16), and low (n = 15) degrees of acclimatization. After characterizing the range of response magnitudes, we further demonstrated that AUC magnitudes were significantly smaller in the Az group compared to the NAz group (P = 0.0021), suggesting improved VA. These results suggest that calculating AUC on modified Fenn diagrams has utility in assessing VA in large groups of trekkers during incremental ascent to HA, due to the associated portability and congruency with known physiology, although this novel analytical method requires further validation in controlled experiments. HIGHLIGHTS: What is the central question of this study? What are the characteristics of a novel methodological approach to assess ventilatory acclimatization (VA) with incremental ascent to high altitude (HA)? What is the main finding and its importance? Area under the curve (AUC) magnitudes calculated from modified Fenn diagrams were significantly smaller in trekkers taking an oral prophylactic dose of acetazolamide compared to an acetazolamide-free group, suggesting improved VA. During incremental HA ascent, quantifying AUC using modified Fenn diagrams is feasible to assess VA in large groups of trekkers with ascent, although this novel analytical method requires further validation in controlled experiments.
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Affiliation(s)
- Rodion Isakovich
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Valerie C. Cates
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Brandon A. Pentz
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Jordan D. Bird
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Emily R. Vanden Berg
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Emily M. de Freitas
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Cassandra E. Nysten
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Jack K. Leacy
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
- Department of Physiology, School of Medicine, College of Medicine & HealthUniversity Cork CollegeCorkIreland
| | - Ken D. O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & HealthUniversity Cork CollegeCorkIreland
| | | | | | - Trevor A. Day
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
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Albertus-Cámara I, Paredes-Ruiz MJ, Martínez-González-Moro I. Analysis of Muscle Oxygenation after a Normobaric Hypoxia Tolerance Test. J Funct Morphol Kinesiol 2024; 9:86. [PMID: 38804452 PMCID: PMC11130857 DOI: 10.3390/jfmk9020086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/02/2024] [Accepted: 05/08/2024] [Indexed: 05/29/2024] Open
Abstract
The aim of this work was to analyze the influence of acute normobaric hypoxia on quadricep oxygenation. Muscle oxygen saturation (SmO2) was measured using near-infrared spectrometry (NIRS) technology during a normobaric hypoxia tolerance test (NHTT). SmO2 was measured with a Humon Hex® device. In total, 54 healthy subjects participated, 68.5 of which were males and 31.5% of which were females. They performed an NHTT with the IAltitude® simulator, breathing air with an FiO2 level of 11% (equivalent to 5050 m). The maximum duration of the NHTT was set at 10 min, stopping if it reached 83% SpO2. The initial values (PRE) were compared with those obtained at the end of the test (POST) and after 10 min of recovery. The participants were divided into two groups based on whether (G1) they completed the ten minutes or not (G2). In total, 35.1% of men and 41.2% of women completed the 10 min. In both groups, significant differences were observed in the decrease in SmO2 values (p < 0.0001) (G1: PRE = 59.5 ± 12.48%; POST = 55.95 ± 14.30%; G2: PRE = 60.06 ± 13.46%; POST = 57.2 ± 12.3%). There were no differences between groups in any of the three periods. Exposure to normobaric hypoxia produces a decrease in quadricep levels of SmO2 in both sexes, regardless of whether the test is completed. Two patterns appeared: A.-less time and more hypoxia; B. a longer duration and less hypoxia.
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Affiliation(s)
| | | | - Ignacio Martínez-González-Moro
- Physical Exercise and Human Performance Research Group, Mare Nostrum Campus, University of Murcia, 30001 Murcia, Spain; (I.A.-C.); (M.-J.P.-R.)
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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: 2] [Impact Index Per Article: 2.0] [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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Patrician A, Anholm JD, Ainslie PN. A narrative review of periodic breathing during sleep at high altitude: From acclimatizing lowlanders to adapted highlanders. J Physiol 2024. [PMID: 38534039 DOI: 10.1113/jp285427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 02/15/2024] [Indexed: 03/28/2024] Open
Abstract
Periodic breathing during sleep at high altitude is almost universal among sojourners. Here, in the context of acclimatization and adaptation, we provide a contemporary review on periodic breathing at high altitude, and explore whether this is an adaptive or maladaptive process. The mechanism(s), prevalence and role of periodic breathing in acclimatized lowlanders at high altitude are contrasted with the available data from adapted indigenous populations (e.g. Andean and Tibetan highlanders). It is concluded that (1) periodic breathing persists with acclimatization in lowlanders and the severity is proportional to sleeping altitude; (2) periodic breathing does not seem to coalesce with poor sleep quality such that, with acclimatization, there appears to be a lengthening of cycle length and minimal impact on the average sleeping oxygen saturation; and (3) high altitude adapted highlanders appear to demonstrate a blunting of periodic breathing, compared to lowlanders, comprising a feature that withstands the negative influences of chronic mountain sickness. These observations indicate that periodic breathing persists with high altitude acclimatization with no obvious negative consequences; however, periodic breathing is attenuated with high altitude adaptation and therefore potentially reflects an adaptive trait to this environment.
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Affiliation(s)
- Alexander Patrician
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, BC, Canada
| | - James D Anholm
- Department of Medicine, Division of Pulmonary and Critical Care, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, BC, Canada
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Hohenauer E, Bianchi G, Wellauer V, Taube W, Clijsen R. Acute physiological responses and muscle recovery in females: a randomised controlled trial of muscle damaging exercise in hypoxia. BMC Sports Sci Med Rehabil 2024; 16:70. [PMID: 38520001 PMCID: PMC10960417 DOI: 10.1186/s13102-024-00861-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 03/11/2024] [Indexed: 03/25/2024]
Abstract
BACKGROUND Studies have investigated the effects of training under hypoxia (HYP) after several weeks in a male population. However, there is still a lack of knowledge on the acute hypoxic effects on physiology and muscle recovery in a female population. METHODS This randomized-controlled trial aimed to investigate the acute effects of muscle damaging exercise, performed in HYP and normoxia (CON), on physiological responses and recovery characteristics in healthy females. Key inclusion criteria were recreationally active female participants between the age of 18 to 35 years without any previous surgeries and injuries, whilst key exclusion criteria were acute pain situations, pregnancy, and medication intake. The females conducted a muscle-damaging protocol, comprising 5 × 20 drop-jumps, in either HYP (FiO2: 12%) or CON (FiO2: 21%). Physiological responses, including capillary oxygenation (SpO2), muscle oxygenation (SmO2), heart rate (HR), core- (Tcore) and skin- (Tskin) temperature were assessed at the end of each exercise set. Recovery characteristics were quantified by taking venous blood samples (serum creatine-kinase [CK], C-reactive protein [CRP] and blood sedimentation rate [BSR]), assessing muscle swelling of the quadriceps femoris muscle, maximum voluntary isometric contraction (MVIC) of the knee extensor muscles, countermovement jump (CMJ) performance and muscle soreness ratings (DOMS) at 24-, 48- and 72-hrs post-exercise. RESULTS SpO2 (HYP: 76.7 ± 3.8%, CON: 95.5 ± 1.7%, p < 0.001) and SmO2 (HYP: 60.0 ± 9.3, CON: 73.4 ± 5.8%, p = 0.03) values were lower (p < 0.05) in HYP compared to CON at the end of the exercise-protocol. No physiological differences between HYP and CON were observed for HR, Tcore, and Tskin (all p > 0.05). There were also no differences detected for any recovery variable (CK, CRP, BSR, MVIC, CMJ, and DOMS) during the 72-hrs follow-up period between HYP and CON (all p > 0.05). CONCLUSION In conclusion, our results showed that muscle damaging exercise under HYP leads to reduced capillary and muscle oxygenation levels compared to normoxia with no difference in inflammatory response and muscle recovery during 72 h post-exercise. TRIAL REGISTRATION NCT04902924, May 26th 2021.
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Affiliation(s)
- Erich Hohenauer
- RESlab, University of Applied Sciences and Arts of Southern Switzerland, Weststrasse 8, CH-7302, Landquart, Switzerland.
- International University of Applied Sciences THIM, Landquart, Switzerland.
- University of Fribourg, Fribourg, Switzerland.
| | - G Bianchi
- RESlab, University of Applied Sciences and Arts of Southern Switzerland, Weststrasse 8, CH-7302, Landquart, Switzerland
| | - V Wellauer
- RESlab, University of Applied Sciences and Arts of Southern Switzerland, Weststrasse 8, CH-7302, Landquart, Switzerland
| | - W Taube
- University of Fribourg, Fribourg, Switzerland
| | - R Clijsen
- RESlab, University of Applied Sciences and Arts of Southern Switzerland, Weststrasse 8, CH-7302, Landquart, Switzerland
- International University of Applied Sciences THIM, Landquart, Switzerland
- Department of Movement and Sport Sciences, Vrije Universiteit Brussel, Brussels, Belgium
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7
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Richter S, Bechmann N. Patient Sex and Origin Influence Distribution of Driver Genes and Clinical Presentation of Paraganglioma. J Endocr Soc 2024; 8:bvae038. [PMID: 38481600 PMCID: PMC10928507 DOI: 10.1210/jendso/bvae038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Indexed: 04/07/2024] Open
Abstract
Context Sexual and ancestral differences in driver gene prevalence have been described in many cancers but have not yet been investigated in pheochromocytoma and paraganglioma (PPGL). Objective This study aims to assess whether sex and ancestry influence prevalence of PPGL driver genes and clinical presentation. Methods We conducted a retrospective analysis of patients with PPGL considering studies from 2010 onwards that included minimal data of type of disease, sex, mutated gene, and country of origin. Additional features were recorded when available (age, tumor location, bilateral or multifocal, somatic or germline, and metastatic disease). Results We included 2162 patients: 877 in Europe and 757 in Asia. Males presented more often with germline pathogenic variants (PVs) in genes activating hypoxia pathways (P = .0006) and had more often sympathetic paragangliomas (P = .0005) and metastasis (P = .0039). On the other hand, females with PPGLs due to MAX PVs were diagnosed later than males (P = .0378) and more often developed metastasis (P = .0497). European but not Asian females presented more often with PPGLs due to PVs in genes related to kinase signaling (P = .0052), particularly RET and TMEM127. Contrary to experiences from Europe, Asian patients with PPGL due to PVs in kinase signaling genes NF1, HRAS, and FGFR1 showed a high proportion of sympathetic tumors, while European patients almost exclusively had adrenal tumors (P < .005). Conclusion Personalized management of patients with PPGL might benefit from considering sexual and ancestral differences. Further studies with better clinically aligned cohorts from various origins are required to better dissect ancestral influences on PPGL development.
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Affiliation(s)
- Susan Richter
- Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
| | - Nicole Bechmann
- Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
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Raberin A, Burtscher J, Citherlet T, Manferdelli G, Krumm B, Bourdillon N, Antero J, Rasica L, Malatesta D, Brocherie F, Burtscher M, Millet GP. Women at Altitude: Sex-Related Physiological Responses to Exercise in Hypoxia. Sports Med 2024; 54:271-287. [PMID: 37902936 PMCID: PMC10933174 DOI: 10.1007/s40279-023-01954-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2023] [Indexed: 11/01/2023]
Abstract
Sex differences in physiological responses to various stressors, including exercise, have been well documented. However, the specific impact of these differences on exposure to hypoxia, both at rest and during exercise, has remained underexplored. Many studies on the physiological responses to hypoxia have either excluded women or included only a limited number without analyzing sex-related differences. To address this gap, this comprehensive review conducted an extensive literature search to examine changes in physiological functions related to oxygen transport and consumption in hypoxic conditions. The review encompasses various aspects, including ventilatory responses, cardiovascular adjustments, hematological alterations, muscle metabolism shifts, and autonomic function modifications. Furthermore, it delves into the influence of sex hormones, which evolve throughout life, encompassing considerations related to the menstrual cycle and menopause. Among these physiological functions, the ventilatory response to exercise emerges as one of the most sex-sensitive factors that may modify reactions to hypoxia. While no significant sex-based differences were observed in cardiac hemodynamic changes during hypoxia, there is evidence of greater vascular reactivity in women, particularly at rest or when combined with exercise. Consequently, a diffusive mechanism appears to be implicated in sex-related variations in responses to hypoxia. Despite well-established sex disparities in hematological parameters, both acute and chronic hematological responses to hypoxia do not seem to differ significantly between sexes. However, it is important to note that these responses are sensitive to fluctuations in sex hormones, and further investigation is needed to elucidate the impact of the menstrual cycle and menopause on physiological responses to hypoxia.
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Affiliation(s)
- Antoine Raberin
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Johannes Burtscher
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Tom Citherlet
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Giorgio Manferdelli
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Bastien Krumm
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Nicolas Bourdillon
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, 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, Canada
| | - Davide Malatesta
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport, Paris, France
| | - 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, Lausanne, Switzerland.
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9
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Lili L, Meydan C, Rickard N, Zhang B. The importance of personalization in high altitude protocols for hematologic and metabolic benefits in sports: A multi-dimensional N-of-1 case study. Heliyon 2024; 10:e23159. [PMID: 38170057 PMCID: PMC10758776 DOI: 10.1016/j.heliyon.2023.e23159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024] Open
Abstract
The hematologic and metabolic benefits of high altitude exposure have been extensively studied in athletes due to their promising performance enhancing effects. However, despite the increased research and development of various high altitude protocols for achieving peak performance, the reproducibility of the results at the individual level remains sparse. To systematically address this limitation and establish a more effective method to achieve consistent results at the individual level, we conducted a multi-dimensional study of one elite endurance athlete in two Phases. In Phase 1, we applied the standard protocol of LHTH (Live-High-Train-High) using a commercially available, at-home, normobaric, high altitude simulation tent under the SHTL (Sleep-High-Train-Low) model. Then, we developed the athlete's personalized protocol for peak hematologic parameters during their off-season. This protocol determined the exact total high altitude exposure time required to achieve peak hematologic parameters, which in the case of this athlete, amounted to 45 nights with approximately 8hrs per night. In Phase 2, we replicated the Phase 1 protocol during the athlete's in-season and observed the same or even higher hematologic and metabolic benefits compared to Phase 1. During both phases, we collected thousands of multi-dimensional data points to ensure that the athlete's lifestyle and environmental factors remained stable, and to increase the likelihood that physiological changes resulted primarily from the high altitude exposure. The data trends in both Phases validated that, for this athlete, hematologic measures such as red blood cell count, hematocrit, and hemoglobin, as well as electrolyte content, body weight and gut microbiome composition improved to their personal best values after a total of approximately 15 days of high altitude exposure (45 nights with roughly 8hrs per night totaling 360hrs or 15days). These improvements did not occur after the 21 days recommended by the LHTH protocol highlighting the significance of personalization in high altitude protocols that are designed for peak performance parameters. Therefore, to maximize the benefits in hematologic and other metabolic values and thus increase muscle oxygen supply and peak aerobic capacity through high altitude exposure, each athlete may require a unique total duration of high altitude exposure tailored to their individual physiology. This duration must be determined by their specific response in hematologic peaking. Therefore, initially establishing a personalized protocol for an athlete by determining their required total duration of high altitude exposure for peak hematologic values during their off-season and applying this protocol during their in-season phase may lead to more successful and reproducible benefits compared to following a generalized protocol alone.
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Affiliation(s)
- Loukia Lili
- Thorne HealthTech, Inc., 152W 57th st, New York, NY 10019, USA
| | - Cem Meydan
- Thorne HealthTech, Inc., 152W 57th st, New York, NY 10019, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10021, USA
| | - Nate Rickard
- Thorne HealthTech, Inc., 152W 57th st, New York, NY 10019, USA
| | - Bodi Zhang
- Thorne HealthTech, Inc., 152W 57th st, New York, NY 10019, USA
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10
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Wait SO, Charkoudian N, Skinner JW, Smith CJ. Combining hypoxia with thermal stimuli in humans: physiological responses and potential sex differences. Am J Physiol Regul Integr Comp Physiol 2023; 324:R677-R690. [PMID: 36971421 PMCID: PMC10202487 DOI: 10.1152/ajpregu.00244.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 03/08/2023] [Accepted: 03/20/2023] [Indexed: 03/29/2023]
Abstract
Increasing prevalence of native lowlanders sojourning to high altitudes (>2,500 m) for recreational, occupational, military, and competitive reasons has generated increased interest in physiological responses to multistressor environments. Exposure to hypoxia poses recognized physiological challenges that are amplified during exercise and further complicated by environments that might include combinations of heat, cold, and high altitude. There is a sparsity of data examining integrated responses in varied combinations of environmental conditions, with even less known about potential sex differences. How this translates into performance, occupational, and health outcomes requires further investigation. Acute hypoxic exposure decreases arterial oxygen saturation, resulting in a reflex hypoxic ventilatory response and sympathoexcitation causing an increase in heart rate, myocardial contractility, and arterial blood pressure, to compensate for the decreased arterial oxygen saturation. Acute altitude exposure impairs exercise performance, for example, reduced time to exhaustion and slower time trials, largely owing to impairments in pulmonary gas exchange and peripheral delivery resulting in reduced V̇o2max. This exacerbates with increasing altitude, as does the risk of developing acute mountain sickness and more serious altitude-related illnesses, but modulation of those risks with additional stressors is unclear. This review aims to summarize and evaluate current literature regarding cardiovascular, autonomic, and thermoregulatory responses to acute hypoxia, and how these may be affected by simultaneous thermal environmental challenges. There is minimal available information regarding sex as a biological variable in integrative responses to hypoxia or multistressor environments; we highlight these areas as current knowledge gaps and the need for future research.
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Affiliation(s)
- Seaver O Wait
- Department of Public Health and Exercise Science, Appalachian State University, Boone, North Carolina, United States
| | - Nisha Charkoudian
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
| | - Jared W Skinner
- Department of Public Health and Exercise Science, Appalachian State University, Boone, North Carolina, United States
| | - Caroline J Smith
- Department of Public Health and Exercise Science, Appalachian State University, Boone, North Carolina, United States
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Vento KA, Borden CK, Blacker KJ. Sex comparisons in physiological and cognitive performance during hypoxic challenge. Front Physiol 2022; 13:1062397. [PMID: 36505049 PMCID: PMC9727089 DOI: 10.3389/fphys.2022.1062397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/11/2022] [Indexed: 11/24/2022] Open
Abstract
Within the tactical aviation community, human performance research lags in considering potential psychophysiological differences between male and female aviators due to little inclusion of females during the design and development of aircraft systems. A poor understanding of how male and female aviators differ with respect to human performance results in unknown potential sex differences on aeromedically relevant environmental stressors, perchance leading to suboptimal performance, safety, and health guidelines. For example, previous hypoxia studies have excluded female participants or lacked a sizeable sample to examine sex comparisons. As such, progress toward sensor development and improving hypoxia familiarization training are stunted due to limited knowledge of how individual differences, including sex, may or may not underlie hypoxia symptoms and performance impairment. Investigating sex differences bridges the gap between aerospace medicine and operational health, and addressing hypoxia is one of many facets yet to be studied. In the current study, we retrospectively examined N = 6 hypoxia studies with male-female participant samples (total, N = 189; male, n = 118; female, n = 71). We explored sex as a predictor of physiological response, sensory deficits, the severity of cognitive performance declines, and symptom manifestation via linear and binary logistic regression models. We found that the female sex predicted lower peripheral oxygen saturation and the likelihood of headache reporting in response to hypoxic challenge, yet explained little variance when combined with age and body mass index. The sensory and cognitive performance models did not converge, suggesting high intra-individual variability. Together, sex, age, and body mass index were not the most robust predictors in responses to hypoxic challenge; we cannot infer this for sensory deficits and cognitive performance within an experimentally induced hypoxic environment. The findings have implications for improving hypoxia familiarization training, monitoring sensor development, and emergency response and recovery protocols in case of a hypoxia occurrence suitable for all aircrew. We recommend continuing to elucidate the impact of sex and intrapersonal differences in hypoxia and other aeromedically relevant stressors in tactical aviation.
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Affiliation(s)
- Kaila A. Vento
- Naval Medical Research Unit-Dayton Wright-Patterson Air Force Base, Dayton, OH, United States,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Cammi K. Borden
- Naval Medical Research Unit-Dayton Wright-Patterson Air Force Base, Dayton, OH, United States,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Kara J. Blacker
- Naval Medical Research Unit-Dayton Wright-Patterson Air Force Base, Dayton, OH, United States,*Correspondence: Kara J. Blacker,
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Horiuchi M, Dobashi S, Kiuchi M, Fukuoka Y, Koyama K. Hypoxic-induced resting ventilatory and circulatory responses under multistep hypoxia is related to decline in peak aerobic capacity in hypoxia. J Physiol Anthropol 2022; 41:36. [PMID: 36280884 PMCID: PMC9590180 DOI: 10.1186/s40101-022-00310-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 10/07/2022] [Indexed: 11/07/2022] Open
Abstract
Background Several factors have been shown to contribute to hypoxic-induced declined in aerobic capacity. In the present study, we investigated the effects of resting hypoxic ventilatory and cardiac responses (HVR and HCR) on hypoxic-induced declines in peak oxygen uptake (\documentclass[12pt]{minimal}
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\begin{document}$$\dot{\mathrm V}$$\end{document}V˙O2peak). Methods Peak oxygen uptakes was measured in normobaric normoxia (room air) and hypoxia (14.1% O2) for 10 young healthy men. The resting HVR and HCR were evaluated at multiple steps of hypoxia (1 h at each of 21, 18, 15 and 12% O2). Arterial desaturation (ΔSaO2) was calculate by the difference between SaO2 at normoxia—at each level of hypoxia (%). HVR was calculate by differences in pulmonary ventilation between normoxia and each level of hypoxia against ΔSaO2 (L min−1 %−1 kg−1). Similarly, HCR was calculated by differences in heart rate between normoxia and each level of hypoxia against ΔSaO2 (beats min−1 %−1). Results \documentclass[12pt]{minimal}
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\begin{document}$$\dot{\mathrm V}$$\end{document}V˙O2peak significantly decreased in hypoxia by 21% on average (P < 0.001). HVR was not associated with changes in \documentclass[12pt]{minimal}
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\begin{document}$$\dot{\mathrm V}$$\end{document}V˙O2peak. ΔSaO2 from normoxia to 18% or 15% O2 and HCR between normoxia and 12% O2 were associated with changes in \documentclass[12pt]{minimal}
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\begin{document}$$\dot{\mathrm V}$$\end{document}V˙O2peak (P < 0.05, respectively). The most optimal model using multiple linear regression analysis found that ΔHCR at 12% O2 and ΔSaO2 at 15% O2 were explanatory variables (adjusted R2 = 0.580, P = 0.02). Conclusion These results suggest that arterial desaturation at moderate hypoxia and heart rate responses at severe hypoxia may account for hypoxic-induced declines in peak aerobic capacity, but ventilatory responses may be unrelated.
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Affiliation(s)
- Masahiro Horiuchi
- grid.419589.80000 0001 0725 4036Faculty of Sports and Life Science, National Institute of Fitness and Sports in Kanoya, Shiromizu town 1, Kanoya city, Kagoshima, 8912393 Japan ,Division of Human Environmental Science, Mt. Fuji Research Institute, Kami-yoshida 5597-1, Fuji-yoshida city, Yamanashi, 4030005 Japan
| | - Shohei Dobashi
- grid.267500.60000 0001 0291 3581Graduate School of Education, University of Yamanashi, Takeda 4-4-37, Kofu city, Yamanashi, 4008510 Japan ,grid.258269.20000 0004 1762 2738Graduate School of Health and Sports Science, Juntendo University, Hiraka-gakuendai 1-1, Inzai city, Chiba, 2701695 Japan
| | - Masataka Kiuchi
- grid.267500.60000 0001 0291 3581Graduate School Department of Interdisciplinary Research, University of Yamanashi, Takeda 4-4-37, Kofu city, Yamanashi, 4008510 Japan
| | - Yoshiyuki Fukuoka
- grid.255178.c0000 0001 2185 2753Faculty of Health and Sports Science, Doshisha University, Tatara-miyakodani 1-3, Kyotanabe city, Kyoto, 6100394 Japan
| | - Katsuhiro Koyama
- grid.267500.60000 0001 0291 3581Graduate School Department of Interdisciplinary Research, University of Yamanashi, Takeda 4-4-37, Kofu city, Yamanashi, 4008510 Japan ,grid.444168.b0000 0001 2161 7710Faculty of Sport Science, Yamanashi Gakuin University, Sakaori 2-4-5, Kofu city, Yamanashi, 4008575 Japan
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13
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Zhao J, Ding Y, Kline GP, Zhou Z, Mallet RT, Shi X. Hypoxic breathing produces more intense hypoxemia in elderly women than in elderly men. Front Physiol 2022; 13:989635. [PMID: 36388125 PMCID: PMC9644051 DOI: 10.3389/fphys.2022.989635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 10/12/2022] [Indexed: 12/03/2022] Open
Abstract
Background: Brief hypoxic exposures are increasingly applied as interventions for aging-related conditions. To optimize the therapeutic impact of hypoxia, knowledge of the sex-related differences in physiological responses to hypoxia is essential. This study compared hypoxia-induced hypoxemic responses in elderly men and women. Methods: Seven elderly men (70.3 ± 6.0 years old) and nine women (69.4 ± 5.5 years old) breathed 10% O2 for 5 min while arterial (SaO2; transcutaneous photoplethysmography) and cerebral tissue O2 saturation (ScO2; near-infrared spectroscopy), ventilatory frequency, tidal volume, minute-ventilation, and partial pressures of end-tidal O2 (PETO2) and CO2 (mass spectrometry) were continuously monitored. Cerebral tissue oxygen extraction fraction (OEF) equaled (SaO2-ScO2)/SaO2. Results: During 5 min hypoxia SaO2 fell from 97.0 ± 0.8% to 80.6 ± 4.6% in the men and from 96.3 ± 1.4% to 72.6 ± 4.0% in the women. The slope ΔSaO2/min was steeper in the women than the men (-4.71 ± 0.96 vs. -3.24 ± 0.76%/min; p = 0.005). Although SaO2 fell twice as sharply per unit decrease in PETO2 in the women than the men (-1.13 ± 0.11 vs. -0.54 ± 0.06%/mmHg; p = 0.003), minute-ventilation per unit hypoxemia increased less appreciably in the women (-0.092 ± 0.014 vs. -0.160 ± 0.021 L/min/%; p = 0.023). OEF fell with hypoxia duration in the women, but remained stable in the men. Conclusion: During 5 min hypoxic breathing, elderly women experience more intense hypoxemia and reduced chemoreflex sensitivity vs. their male counterparts, which may lower OEF stability in women despite augmented O2 dissociation from hemoglobin during hypoxia. These sex-related differences merit attention when implementing brief hypoxic exposures for therapeutic purposes.
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Affiliation(s)
- Jinfeng Zhao
- Departments of Pharmacology and Neuroscience, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, United States.,School of Physical Education, Shanxi University, Taiyuan, China
| | - Yanfeng Ding
- Internal Medicine, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Geoffrey P Kline
- Internal Medicine, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Zhengyang Zhou
- Biostatistics and Epidemiology, School of Public Health, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Robert T Mallet
- Physiology and Anatomy, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Xiangrong Shi
- Departments of Pharmacology and Neuroscience, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, United States
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