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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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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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Goodrich JA, Ryan BJ, Byrnes WC. The Influence of Oxygen Saturation on the Relationship Between Hemoglobin Mass and VO 2 max. Sports Med Int Open 2018; 2:E98-E104. [PMID: 30539125 PMCID: PMC6225968 DOI: 10.1055/a-0655-7207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 05/11/2018] [Accepted: 06/05/2018] [Indexed: 11/04/2022] Open
Abstract
Hemoglobin mass (tHb) is a key determinant of maximal oxygen uptake (VO
2
max). We examined whether oxyhemoglobin desaturation (ΔS
a
O
2
) at VO
2
max modifies the relationship between tHb and VO
2
max at moderate altitude (1,625 m). Seventeen female and 16 male competitive, endurance-trained moderate-altitude residents performed two tHb assessments and two graded exercise tests on a cycle ergometer to determine VO
2
max and ΔS
a
O
2
. In males and females respectively, VO
2
max (ml·kg
−1
·min
−1
) ranged from 62.5–83.0 and 44.5–67.3; tHb (g·kg
−1
) ranged from 12.1–17.5 and 9.1–13.0; and S
a
O
2
at VO
2
max (%) ranged from 81.7–94.0 and 85.7–95.0. tHb was related to VO
2
max when expressed in absolute terms and after correcting for body mass (r=0.94 and 0.86, respectively); correcting by ΔS
a
O
2
did not improve these relationships (r=0.93 and 0.83). Additionally, there was a negative relationship between tHb and S
a
O
2
at VO
2
max (r=–0.57). In conclusion, across a range of endurance athletes at moderate altitude, the relationship between tHb and VO
2
max was found to be similar to that observed at sea level. However, correcting tHb by ΔS
a
O
2
did not explain additional variability in VO
2
max despite significant variability in ΔS
a
O
2
; this raises the possibility that tHb and exercise-induced ΔS
a
O
2
are not independent in endurance athletes.
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Affiliation(s)
- Jesse A Goodrich
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, United States
| | - Benjamin J Ryan
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, United States
| | - William C Byrnes
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, United States
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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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Edwards AG, Hill JO, Byrnes WC, Browning RC. Accuracy of optimized branched algorithms to assess activity-specific physical activity energy expenditure. Med Sci Sports Exerc 2011; 42:672-82. [PMID: 19952842 DOI: 10.1249/mss.0b013e3181bd196d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To assess the activity-specific accuracy achievable by branched algorithm (BA) analysis of simulated daily living physical activity energy expenditure (PAEE) within a sedentary population. METHODS Sedentary men (n = 8) and women (n = 8) first performed a treadmill calibration protocol, during which HR, accelerometry (ACC), and PAEE were measured in 1-min epochs. From these data, HR-PAEE and ACC-PAEE regressions were constructed and used in each of six analytic models to predict PAEE from ACC and HR data collected during a subsequent simulated daily living protocol. Criterion PAEE was measured during both protocols via indirect calorimetry. The accuracy achieved by each model was assessed by the root mean square of the difference between model-predicted daily living PAEE and the criterion daily living PAEE (expressed here as percent of mean daily living PAEE). RESULTS Across the range of activities, an unconstrained post hoc-optimized BA best predicted criterion PAEE. Estimates using individual calibration were generally more accurate than those using group calibration (14% vs 16% error, respectively). These analyses also performed well within each of the six daily living activities, but systematic errors appeared for several of those activities, which may be explained by an inability of the algorithm to simultaneously accommodate a heterogeneous range of activities. Analyses between mean square error by subject and activity suggest that optimization involving minimization of root mean square for total daily living PAEE is associated with decreased error between subjects but increased error between activities. CONCLUSIONS The performance of post hoc-optimized BA may be limited by heterogeneity in the daily living activities being performed.
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Affiliation(s)
- Andy G Edwards
- Integrative Physiology, University of Colorado at Boulder, Boulder, CO, USA
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