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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: 6] [Impact Index Per Article: 6.0] [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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Thomas NT, Confides AL, Fry CS, Dupont-Versteegden EE. Satellite cell depletion does not affect diaphragm adaptations to hypoxia. J Appl Physiol (1985) 2022; 133:637-646. [PMID: 35861521 PMCID: PMC9448290 DOI: 10.1152/japplphysiol.00083.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 07/01/2022] [Accepted: 07/13/2022] [Indexed: 01/25/2023] Open
Abstract
The diaphragm is the main skeletal muscle responsible for inspiration and is susceptible to age-associated decline in function and morphology. Satellite cells in diaphragm fuse into unperturbed muscle fibers throughout life, yet their role in adaptations to hypoxia in diaphragm is unknown. Given their continual fusion, we hypothesize that satellite cell depletion will negatively impact adaptations to hypoxia in the diaphragm, particularly with aging. We used the Pax7CreER/CreER:R26RDTA/DTA genetic mouse model of inducible satellite cell depletion to investigate diaphragm responses to hypoxia in adult (6 mo) and aged (22 mo) male mice. The mice were subjected to normobaric hypoxia at 10% [Formula: see text] or normoxia for 4 wk. We showed that satellite cell depletion had no effect on diaphragm muscle fiber cross-sectional area, fiber-type distribution, myonuclear density, or regulation of extracellular matrix in either adult or aged mice. Furthermore, we showed lower muscle fiber cross-sectional area with hypoxia and age (main effects), while extracellular matrix content was higher and satellite cell abundance was lower with age (main effect) in diaphragm. Lastly, a greater number of Pax3-mRNA+ cells was observed in diaphragm muscle of satellite cell-depleted mice independent of hypoxia (main effect), potentially as a compensatory mechanism for the loss of satellite cells. We conclude that satellite cells are not required for diaphragm muscle adaptations to hypoxia in either adult or aged mice.NEW & NOTEWORTHY Satellite cells show consistent fusion into diaphragm muscle fibers throughout life, suggesting a critical role in maintaining homeostasis. Here, we report identical diaphragm adaptations to hypoxia with and without satellite cells in adult and aged mice. In addition, we propose that the higher number of Pax3-positive cells in satellite cell-depleted diaphragm muscle acts as a compensatory mechanism.
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Affiliation(s)
- Nicholas T Thomas
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, Kentucky
| | - Amy L Confides
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
- Department of Physical Therapy, University of Kentucky, Lexington, Kentucky
| | - Christopher S Fry
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, Kentucky
| | - Esther E Dupont-Versteegden
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
- Department of Physical Therapy, University of Kentucky, Lexington, Kentucky
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3
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Szymczak RK, Grzywacz T, Ziemann E, Sawicka M, Laskowski R. Prolonged Sojourn at Very High Altitude Decreases Sea-Level Anaerobic Performance, Anaerobic Threshold, and Fat Mass. Front Physiol 2021; 12:743535. [PMID: 34675820 PMCID: PMC8523780 DOI: 10.3389/fphys.2021.743535] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 09/13/2021] [Indexed: 11/22/2022] Open
Abstract
Background: The influence of high altitude on an organism’s physiology depends on the length and the level of hypoxic exposure it experiences. This study aimed to determine the effect of a prolonged sojourn at very high altitudes (above 3,500m) on subsequent sea-level physical performance, body weight, body composition, and hematological parameters. Materials and Methods: Ten alpinists, nine males and one female, with a mean age of 27±4years, participated in the study. All had been on mountaineering expeditions to 7,000m peaks, where they spent 30±1days above 3,500m with their average sojourn at 4,900±60m. Their aerobic and anaerobic performance, body weight, body composition, and hematological parameters were examined at an altitude of 100m within 7days before the expeditions and 7days after they descended below 3,500m. Results: We found a significant (p<0.01) decrease in maximal anaerobic power (MAPWAnT) from 9.9±1.3 to 9.2±1.3W·kg−1, total anaerobic work from 248.1±23.8 to 228.1±20.1J·kg−1, anaerobic threshold from 39.3±8.0 to 27.8±5.6 mlO2·kg−1·min−1, body fat mass from 14.0±3.1 to 11.5±3.3%, and a significant increase (p<0.05) in maximal tidal volume from 3.2 [3.0–3.2] to 3.5 [3.3–3.9] L after their sojourn at very high attitude. We found no significant changes in maximal aerobic power, maximal oxygen uptake, body weight, fat-free mass, total body water, hemoglobin, and hematocrit. Conclusion: A month-long exposure to very high altitude led to impaired sea-level anaerobic performance and anaerobic threshold, increased maximal tidal volume, and depleted body fat mass, but had no effect on maximal aerobic power, maximal oxygen uptake, or hemoglobin and hematocrit levels.
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Affiliation(s)
- Robert K Szymczak
- Department of Emergency Medicine, Faculty of Health Sciences, Medical University of Gdańsk, Gdańsk, Poland
| | - Tomasz Grzywacz
- Department of Sport, Institute of Physical Culture, Kazimierz Wielki University in Bydgoszcz, Bydgoszcz, Poland
| | - Ewa Ziemann
- Department of Athletics, Strength and Conditioning, Poznań University of Physical Education, Poznan, Poland
| | - Magdalena Sawicka
- Department of Neurology, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Radosław Laskowski
- Department of Physiology and Biochemistry, Gdańsk University of Physical Education and Sport, Gdańsk, Poland
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Almeida F, Padial P, Bonitch-Góngora J, de la Fuente B, Schoenfeld BJ, Morales-Artacho AJ, Benavente C, Feriche B. Effects of Power-Oriented Resistance Training During an Altitude Camp on Strength and Technical Performance of Elite Judokas. Front Physiol 2021; 12:606191. [PMID: 33679430 PMCID: PMC7930574 DOI: 10.3389/fphys.2021.606191] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 01/25/2021] [Indexed: 12/29/2022] Open
Abstract
This study investigated the effect of a 3-week power-oriented resistance training program performed at moderate altitude on leg power output variables in a countermovement jump, a related judo technique (ippon-seoi-nage) and the relationship between them. Twenty-four elite male judokas were randomly assigned to a hypobaric hypoxia or normoxia group. Mechanical outputs from an incremental loaded countermovement jump test and the kinematic variables transferred to a dummy during an ippon-seoi-nage test (time to execution and movement accelerations) were assessed before, after, 1 and 2 weeks after training. Results indicated an increase in explosive leg capacity both at moderate altitude (2320 m.a.s.l.) and sea level. The hypoxia group showed additional benefits when compared to normoxia group for peak velocities with different percentages of the body weight, maximal theoretical velocity and jump height after the training period, and these additional benefits in jump height were maintained 2 weeks after training. The hypoxia group achieved a higher peak performance in peak velocity and jump height than normoxia group (peak velocity: 8.8 vs. 5.6%, jump height: 8.2 vs. 1.4%, respectively) and was achieved earlier in hypoxia (after training) than in normoxia (1 week after training). However, there was a detrimental effect for the hypoxia group on the times of execution and acceleration of the ippon-seoi-nage compared to the normoxia group. These results suggest that altitude training may induce faster and greater improvements in explosive leg extension capacity. Specific technique-oriented training should be included at altitude to prevent technique impairment.
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Affiliation(s)
- Filipa Almeida
- Department of Physical Education and Sport, University of Granada, Granada, Spain
| | - Paulino Padial
- Department of Physical Education and Sport, University of Granada, Granada, Spain
| | - Juan Bonitch-Góngora
- Department of Physical Education and Sport, University of Granada, Granada, Spain
| | - Blanca de la Fuente
- High Performance Center of Sierra Nevada, Spanish Sport Council, Granada, Spain
| | - Brad J Schoenfeld
- Department of Health Sciences, CUNY Lehman College, New York, NY, United States
| | - Antonio J Morales-Artacho
- Department of Physical Education and Sport, University of Granada, Granada, Spain.,Laboratory Sport, Expertise and Performance (EA 7370), Research Department, French Institute of Sport (INSEP), Paris, France
| | - Cristina Benavente
- Department of Physical Education and Sport, University of Granada, Granada, Spain
| | - Belén Feriche
- Department of Physical Education and Sport, University of Granada, Granada, Spain
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Doria C, Verratti V, Pietrangelo T, Fanò-Illic G, Bisconti AV, Shokohyar S, Rampichini S, Limonta E, Coratella G, Longo S, Cè E, Esposito F. Changes in energy system contributions to the Wingate anaerobic test in climbers after a high altitude expedition. Eur J Appl Physiol 2020; 120:1629-1636. [PMID: 32494861 DOI: 10.1007/s00421-020-04392-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 05/12/2020] [Indexed: 12/12/2022]
Abstract
PURPOSE The Wingate anaerobic test measures the maximum anaerobic capacity of the lower limbs. The energy sources of Wingate test are dominated by anaerobic metabolism (~ 80%). Chronic high altitude exposure induces adaptations on skeletal muscle function and metabolism. Therefore, the study aim was to investigate possible changes in the energy system contribution to Wingate test before and after a high-altitude sojourn. METHODS Seven male climbers performed a Wingate test before and after a 43-day expedition in the Himalaya (23 days above 5.000 m). Mechanical parameters included: peak power (PP), average power (AP), minimum power (MP) and fatigue index (FI). The metabolic equivalents were calculated as aerobic contribution from O2 uptake during the 30-s exercise phase (WVO2), lactic and alactic anaerobic energy sources were determined from net lactate production (WLa) and the fast component of the kinetics of post-exercise oxygen uptake (WPCr), respectively. The total metabolic work (WTOT) was calculated as the sum of the three energy sources. RESULTS PP and AP decreased from 7.3 ± 1.1 to 6.7 ± 1.1 W/kg and from 5.9 ± 0.7 to 5.4 ± 0.8 W/kg, respectively, while FI was unchanged. WTOT declined from 103.9 ± 28.7 to 83.8 ± 17.8 kJ. Relative aerobic contribution remained unchanged (19.9 ± 4.8% vs 18.3 ± 2.3%), while anaerobic lactic and alactic contributions decreased from 48.3 ± 11.7 to 43.1 ± 8.9% and increased from 31.8 ± 14.5 to 38.6 ± 7.4%, respectively. CONCLUSION Chronic high altitude exposure induced a reduction in both mechanical and metabolic parameters of Wingate test. The anaerobic alactic relative contribution increased while the anaerobic lactic decreased, leaving unaffected the overall relative anaerobic contribution to Wingate test.
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Affiliation(s)
- Christian Doria
- Department of Biomedical Sciences for Health, Università Degli Studi Di Milano, Via G. Colombo 71, 20133, Milan, Italy.
| | - V Verratti
- Department of Psychological Sciences, Health and Territory, University "G. D'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - T Pietrangelo
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. D'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - G Fanò-Illic
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. D'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - A V Bisconti
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - S Shokohyar
- Department of Biomedical Sciences for Health, Università Degli Studi Di Milano, Via G. Colombo 71, 20133, Milan, Italy
| | - S Rampichini
- Department of Biomedical Sciences for Health, Università Degli Studi Di Milano, Via G. Colombo 71, 20133, Milan, Italy
| | - E Limonta
- Department of Biomedical Sciences for Health, Università Degli Studi Di Milano, Via G. Colombo 71, 20133, Milan, Italy.,IRCCS, Istituto Ortopedico Galeazzi, Milan, Italy
| | - G Coratella
- Department of Biomedical Sciences for Health, Università Degli Studi Di Milano, Via G. Colombo 71, 20133, Milan, Italy
| | - S Longo
- Department of Biomedical Sciences for Health, Università Degli Studi Di Milano, Via G. Colombo 71, 20133, Milan, Italy
| | - E Cè
- Department of Biomedical Sciences for Health, Università Degli Studi Di Milano, Via G. Colombo 71, 20133, Milan, Italy.,IRCCS, Istituto Ortopedico Galeazzi, Milan, Italy
| | - F Esposito
- Department of Biomedical Sciences for Health, Università Degli Studi Di Milano, Via G. Colombo 71, 20133, Milan, Italy.,IRCCS, Istituto Ortopedico Galeazzi, Milan, Italy
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Morales-Artacho AJ, Padial P, García-Ramos A, Pérez-Castilla A, Argüelles-Cienfuegos J, De la Fuente B, Feriche B. Intermittent Resistance Training at Moderate Altitude: Effects on the Force-Velocity Relationship, Isometric Strength and Muscle Architecture. Front Physiol 2018; 9:594. [PMID: 29882549 PMCID: PMC5976859 DOI: 10.3389/fphys.2018.00594] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/02/2018] [Indexed: 11/13/2022] Open
Abstract
Intermittent hypoxic resistance training (IHRT) may help to maximize the adaptations following resistance training, although conflicting evidence is available. The aim of this study was to explore the influence of moderate altitude on the functional, neural and muscle architecture responses of the quadriceps muscles following a power-oriented IHRT intervention. Twenty-four active males completed two 4-week consecutive training blocks comprising general strengthening exercises (weeks 1–4) and power-oriented resistance training (weeks 5–8). Training sessions were conducted twice a week at moderate altitude (2320 m; IHRT, n = 13) or normoxia (690 m; NT, n = 11). Training intensity during the second training block was set to the individual load corresponding to a barbell mean propulsive velocity of 1 m·s−1. Pre-post assessments, performed under normoxic conditions, comprised quadriceps muscle architecture (thickness, pennation angle and fascicle length), isometric maximal (MVF) and explosive strength, and voluntary muscle activation. Dynamic strength performance was assessed through the force-velocity relationship (F0, V0, P0) and a repeated CMJ test (CMJ15MP). Region-specific muscle thickness changes were observed in both training groups (p < 0.001, ηG2 = 0.02). A small opposite trend in pennation angle changes was observed (ES [90% CI]: −0.33 [−0.65, −0.01] vs. 0.11 [−0.44, 0.6], in the IHRT and NT group, respectively; p = 0.094, ηG2 = 0.02). Both training groups showed similar improvements in MVF (ES: 0.38 [0.20, 0.56] vs. 0.55 [0.29, 0.80], in the IHRT and NT group, respectively; p = 0.645, ηG2 < 0.01), F0 (ES: 0.41 [−0.03, 0.85] vs. 0.52 [0.04, 0.99], in the IHRT and NT group, respectively; p = 0.569, ηG2 < 0.01) and P0 (ES: 0.53 [0.07, 0.98] vs. 0.19 [−0.06, 0.44], in the IHRT and NT group, respectively; p = 0.320, ηG2 < 0.01). No meaningful changes in explosive strength performance were observed. In conclusion, contrary to earlier adverse associations between altitude and resistance-training muscle adaptations, similar anatomical and functional muscle strength responses can be achieved in both environmental conditions. The observed region-specific muscle thickness changes may encourage further research on the potential influence of IHRT on muscle morphological changes.
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Affiliation(s)
- Antonio J Morales-Artacho
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Paulino Padial
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Amador García-Ramos
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Alejandro Pérez-Castilla
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | | | - Blanca De la Fuente
- High Performance Center of Sierra Nevada, Spanish Sport Council, Granada, Spain
| | - Belén Feriche
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
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Feriche B, García-Ramos A, Morales-Artacho AJ, Padial P. Resistance Training Using Different Hypoxic Training Strategies: a Basis for Hypertrophy and Muscle Power Development. SPORTS MEDICINE-OPEN 2017; 3:12. [PMID: 28315193 PMCID: PMC5357242 DOI: 10.1186/s40798-017-0078-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 02/23/2017] [Indexed: 12/14/2022]
Abstract
The possible muscular strength, hypertrophy, and muscle power benefits of resistance training under environmental conditions of hypoxia are currently being investigated.Nowadays, resistance training in hypoxia constitutes a promising new training strategy for strength and muscle gains. The main mechanisms responsible for these effects seem to be related to increased metabolite accumulation due to hypoxia. However, no data are reported in the literature to describe and compare the efficacy of the different hypertrophic resistance training strategies in hypoxia.Moreover, improvements in sprinting, jumping, or throwing performance have also been described at terrestrial altitude, encouraging research into the speed of explosive movements at altitude. It has been suggested that the reduction in the aerodynamic resistance and/or the increase in the anaerobic metabolism at higher altitudes can influence the metabolic cost, increase the take-off velocities, or improve the motor unit recruitment patterns, which may explain these improvements. Despite these findings, the applicability of altitude conditions in improving muscle power by resistance training remains to be clarified.This review examines current knowledge regarding resistance training in different types of hypoxia, focusing on strategies designed to improve muscle hypertrophy as well as power for explosive movements.
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Affiliation(s)
- Belén Feriche
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Crta Alfacar sn, 18011, Granada, Spain.
| | - Amador García-Ramos
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Crta Alfacar sn, 18011, Granada, Spain
| | - Antonio J Morales-Artacho
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Crta Alfacar sn, 18011, Granada, Spain
| | - Paulino Padial
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Crta Alfacar sn, 18011, Granada, Spain
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García-Ramos A, Padial P, De la Fuente B, Argüelles-Cienfuegos J, Bonitch-Góngora J, Feriche B. The Effect of Acute and Chronic Exposure to Hypobaric Hypoxia on Loaded Squat Jump Performance. J Hum Kinet 2017; 56:149-158. [PMID: 28469753 PMCID: PMC5384062 DOI: 10.1515/hukin-2017-0032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The present study aimed (1) to compare loaded squat jump performance after an acute and chronic exposure to a moderate natural altitude between normoxia and hypobaric hypoxia conditions, and (2) to analyze the effect of an altitude training camp on loaded jump squat development. Sixteen male swimmers (17.1 ± 0.8 years) took part in a 17-day training camp at a natural moderate altitude. They were randomly tested in counterbalanced order on days 1 and 3 in normoxia and hypoxia (pretest) and on days 15 and 17 again in normoxia and hypoxia (posttest). The peak velocity reached with loads equivalent to 25%, 50%, 75% and 100% of swimmers' pretest body weight in the loaded squat jump exercise was the dependent variable analyzed. An overall increase in peak velocity during the test performed in hypoxia of 6.5% in pretest (p < 0.001, ES = 0.98) and 4.5% in posttest (p < 0.001, ES = 0.81) was observed. An overall increment in peak velocity of 4.0% considering the data for normoxia tests (p < 0.001, ES = 0.61) and 2.1% considering the data for hypoxia tests (p = 0.008, ES = 0.36) was achieved after the altitude training camp. These results highlight the beneficial effects of hypobaric hypoxia on jump performance after short and longer term exposure to a natural moderate altitude. The increase in loaded squat jump performance following the 17-day training camp suggests that altitude training could constitute a favorable stimulus in explosive strength.
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Affiliation(s)
- Amador García-Ramos
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Spain
| | - Paulino Padial
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Spain
| | | | | | - Juan Bonitch-Góngora
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Spain
| | - Belén Feriche
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Spain
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The Effect of an Altitude Training Camp on Swimming Start Time and Loaded Squat Jump Performance. PLoS One 2016; 11:e0160401. [PMID: 27467760 PMCID: PMC4965075 DOI: 10.1371/journal.pone.0160401] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 07/19/2016] [Indexed: 11/20/2022] Open
Abstract
This study evaluated the influence of an altitude training (AT) camp on swimming start time and loaded squat jump performance. To accomplish this goal, 13 international swimmers (8 women, 5 men) were allocated to both the control (Sea Level Training, SLT) and experimental conditions (AT, 2320 m above sea level) that were separated by a one year period. All tests (15 m freestyle swimming start and loaded squat jumps with additional loads of 25%, 50%, 75%, and 100% of swimmers' body weight) were performed before and after a concurrent 3-week strength and endurance training program prescribed by the national coach. Following the SLT camp, significant impairments in swimming start times to 10 (+3.1%) and 15 m (+4.0%) were observed (P < 0.05), whereas no significant changes for the same distances were detected following the AT camp (-0.89%; P > 0.05). Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: < 0.20). Based on these results we can conclude that a traditional training high-living high strategy concurrent training of 3 weeks does not adversely affect swimming start time and loaded squat jump performance in high level swimmers, but further studies are necessary to assess the effectiveness of power-oriented resistance training in the development of explosive actions.
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10
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The effects of negative work on the maximal instantaneous muscular power of humans during vertical jumps. SPORT SCIENCES FOR HEALTH 2015. [DOI: 10.1007/s11332-015-0229-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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Feriche B, García-Ramos A, Calderón-Soto C, Drobnic F, Bonitch- Góngora JG, Galilea PA, Riera J, Padial P. Effect of acute exposure to moderate altitude on muscle power: hypobaric hypoxia vs. normobaric hypoxia. PLoS One 2014; 9:e114072. [PMID: 25474104 PMCID: PMC4256399 DOI: 10.1371/journal.pone.0114072] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 11/03/2014] [Indexed: 12/27/2022] Open
Abstract
When ascending to a higher altitude, changes in air density and oxygen levels affect the way in which explosive actions are executed. This study was designed to compare the effects of acute exposure to real or simulated moderate hypoxia on the dynamics of the force-velocity relationship observed in bench press exercise. Twenty-eight combat sports athletes were assigned to two groups and assessed on two separate occasions: G1 (n = 17) in conditions of normoxia (N1) and hypobaric hypoxia (HH) and G2 (n = 11) in conditions of normoxia (N2) and normobaric hypoxia (NH). Individual and complete force-velocity relationships in bench press were determined on each assessment day. For each exercise repetition, we obtained the mean and peak velocity and power shown by the athletes. Maximum power (Pmax) was recorded as the highest P(mean) obtained across the complete force-velocity curve. Our findings indicate a significantly higher absolute load linked to P(max) (∼ 3%) and maximal strength (1 RM) (∼ 6%) in G1 attributable to the climb to altitude (P<0.05). We also observed a stimulating effect of natural hypoxia on P(mean) and P(peak) in the middle-high part of the curve (≥ 60 kg; P<0.01) and a 7.8% mean increase in barbell displacement velocity (P<0.001). No changes in any of the variables examined were observed in G2. According to these data, we can state that acute exposure to natural moderate altitude as opposed to simulated normobaric hypoxia leads to gains in 1 RM, movement velocity and power during the execution of a force-velocity curve in bench press.
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Affiliation(s)
- Belén Feriche
- Department of Physical Education and Sport, University of Granada, Granada, Spain
| | - Amador García-Ramos
- Department of Physical Education and Sport, University of Granada, Granada, Spain
| | | | - Franchek Drobnic
- Department of Sport Physiology, Grup d’Investigació en el Rendiment i la Salut de l’Esportista d’Alt Nivell Esportiu del Centre D'Alt Rendiment, High Sport Council, Barcelona, Spain
| | | | - Pedro A. Galilea
- Department of Sport Physiology, Grup d’Investigació en el Rendiment i la Salut de l’Esportista d’Alt Nivell Esportiu del Centre D'Alt Rendiment, High Sport Council, Barcelona, Spain
| | - Joan Riera
- Department of Sport Physiology, Grup d’Investigació en el Rendiment i la Salut de l’Esportista d’Alt Nivell Esportiu del Centre D'Alt Rendiment, High Sport Council, Barcelona, Spain
| | - Paulino Padial
- Department of Physical Education and Sport, University of Granada, Granada, Spain
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Kayser B. Pro: All dwellers at high altitude are persons of impaired physical and mental powers. High Alt Med Biol 2014; 14:205-7. [PMID: 24067175 DOI: 10.1089/ham.2013.1045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Bengt Kayser
- Institute of Sports Sciences of the University of Lausanne , Lausanne, Switzerland
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Ermolao A, Bergamin M, Rossi AC, Dalle Carbonare L, Zaccaria M. Cardiopulmonary response and body composition changes after prolonged high altitude exposure in women. High Alt Med Biol 2012; 12:357-69. [PMID: 22206562 DOI: 10.1089/ham.2010.1098] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Weight loss in men is commonly observed during prolonged high altitude exposure as a result of a daily negative energy balance. Its amount depends mainly on duration of exposure, altitude reached, and level of physical activity. This reduction in body weight often comes with a loss of muscular mass, likely contributing to the decreased physical performance generally reported. Limited data is, however, available on body composition, functional capacity, and cardiopulmonary response to exercise after high altitude exposure in women. The aim of this study was to evaluate the effects of prolonged high altitude exposure on body composition and on cardiopulmonary response to maximal exercise in a group of young, moderately active women. Twelve female subjects, aged 21.5 ± 3.1 (mean ± SD), BMI 22.1 ± 1.9 kg · m(-2) and Vo(2max) 33.8 ± 3.5 mL · kg(-1) · min(-1), participated in this study, by residing for 21 days at high altitude (5050 m, Pyramid, EV-K(2)-CNR laboratory). Before and after high altitude exposure, all subjects underwent both a body composition evaluation using two methods (bioimpedance analysis and DEXA) and a functional evaluation based on a maximal exercise test on a cycle ergometer with breath-by-breath gas analysis. After high altitude exposure, data showed a slight, nonsignificant reduction in body weight, with an average 3:2 reduction ratio between fat and fat-free mass evaluated by DEXA, in addition to a significant decrease in Vo(2max) on the cycle ergometer test (p<0.01). Changes in Vo(2max) correlated to changes of leg muscle mass, evaluated by DEXA (r(2) = 0.72; p<0.0001). No changes were observed in the maximal heart rate, work capacity, and ventilatory thresholds, while the Vo(2)/W slope was significantly reduced (p<0.05). Finally, Ve/Vo(2) and VE/Vco(2max) slopes were increased (p<0.01), suggesting a possible long-term modulation of the exercise ventilatory response after prolonged high altitude exposure.
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Affiliation(s)
- Andrea Ermolao
- Department of Medical and Surgical Sciences, Sports Medicine Unit, University of Padova, Padova, Italy
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14
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Hypoxia Increases Muscle Hypertrophy Induced by Resistance Training. Int J Sports Physiol Perform 2010; 5:497-508. [DOI: 10.1123/ijspp.5.4.497] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Purpose:Recent studies have shown that low-intensity resistance training with vascular occlusion (kaatsu training) induces muscle hypertrophy. A local hypoxic environment facilitates muscle hypertrophy during kaatsu training. We postulated that muscle hypertrophy can be more efficiently induced by placing the entire body in a hypoxic environment to induce muscle hypoxia followed by resistance training.Methods:Fourteen male university students were randomly assigned to hypoxia (Hyp) and normoxia (Norm) groups (n = 7 per group). Each training session proceeded at an exercise intensity of 70% of 1 repetition maximum (RM), and comprised four sets of 10 repetitions of elbow extension and fexion. Students exercised twice weekly for 6 wk and then muscle hypertrophy was assessed by magnetic resonance imaging and muscle strength was evaluated based on 1RM.Results:Muscle hypertrophy was significantly greater for the Hyp-Ex (exercised fexor of the hypoxia group) than for the Hyp-N (nonexercised fexor of the hypoxia group) or Norm-Ex fexor (P < .05, Bonferroni correction). Muscle hypertrophy was significantly greater for the Hyp-Ex than the Hyp-N extensor. Muscle strength was significantly increased early (by week 3) in the Hyp-Ex, but not in the Norm-Ex group.Conclusion:This study suggests that resistance training under hypoxic conditions improves muscle strength and induces muscle hypertrophy faster than under normoxic conditions, thus representing a promising new training technique.
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Esteva S, Pedret R, Fort N, Torrella JR, Pagès T, Viscor G. Oxidative stress status in rats after intermittent exposure to hypobaric hypoxia. Wilderness Environ Med 2010; 21:325-31. [PMID: 21168785 DOI: 10.1016/j.wem.2010.09.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Revised: 09/08/2010] [Accepted: 09/08/2010] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Programs of intermittent hypobaric hypoxia (IHH) exposure are used to raise hemoglobin concentration and erythrocyte mass. Although acclimation response increases blood oxygen transport capacity leading to a VO(2max) increase, the effects of reactive oxygen species (ROS) might determine the behavior of erythrocytes and plasma, thus causing a worse peripheral blood flow. The goals of the study were to establish the hematological changes and to discern whether an IHH protocol modifies the antioxidant/pro-oxidant balance in laboratory rats. METHODS Male rats were subjected to an IHH program consisting of a daily 4-hour session for 5 days/week until completing 22 days of hypoxia exposure in a hypobaric chamber at a simulated altitude of 5000 m. Blood samples were taken at the end of the exposure period (H) and at 20 (P20) and 40 (P40) days after the end of the program, and compared to control (C), maintained at sea-level pressure. Hematological parameters were measured together with several oxidative stress indicators: plasma thiobarbituric acid reactive substances (TBARS) and erythrocyte catalase (CAT) and superoxide dismutase (SOD). RESULTS Red blood cell (RBC) count, hemoglobin concentration and hematocrit were higher in H group as compared to all the other groups (p < 0.001). However, there were no significant differences between the 4 groups in any of the oxidative stress-related parameters. CONCLUSIONS The absence of significant differences between groups indicates that our IHH program has little impact on the general redox status, even in the laboratory rat, which is more sensitive to hypoxia than humans. We conclude that IHH does not increase oxidative stress.
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Affiliation(s)
- Santiago Esteva
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 645, Barcelona, Spain
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Changes in contractile properties of skinned single rat soleus and diaphragm fibres after chronic hypoxia. Pflugers Arch 2010; 460:863-73. [PMID: 20697736 DOI: 10.1007/s00424-010-0866-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 07/08/2010] [Accepted: 07/20/2010] [Indexed: 01/03/2023]
Abstract
Hypoxia may be one of the factors underlying muscle dysfunction during ageing and chronic lung and heart failure. Here we tested the hypothesis that chronic hypoxia per se affects contractile properties of single fibres of the soleus and diaphragm muscle. To do this, the force-velocity relationship, rate of force redevelopment and calcium sensitivity of single skinned fibres from normoxic rats and rats exposed to 4 weeks of hypobaric hypoxia (410 mmHg) were investigated. The reduction in maximal force (P(0)) after hypoxia (p=0.031) was more pronounced in type IIa than type I fibres and was mainly attributable to a reduction in fibre cross-sectional area (p=0.044). In type IIa fibres this was aggravated by a reduction in specific tension (p=0.001). The maximal velocity of shortening (V (max)) and shape of the force velocity relation (a/P(0)), however, did not differ between normoxic and hypoxic muscle fibres and the reduction in maximal power of hypoxic fibres (p=0.012) was mainly due to a reduction in P(0). In conclusion, chronic hypoxia causes muscle fibre dysfunction which is not only due to a loss of muscle mass, but also to a diminished force generating capacity of the remaining contractile material. These effects are similar in the soleus and diaphragm muscle, but more pronounced in type IIa than I fibres.
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17
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Esteva S, Panisello P, Torrella JR, Pagés T, Viscor G. Blood rheology adjustments in rats after a program of intermittent exposure to hypobaric hypoxia. High Alt Med Biol 2009; 10:275-81. [PMID: 19775218 DOI: 10.1089/ham.2008.1086] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Intermittent hypobaric hypoxia (IHH) exposure induces a rise in hemoglobin concentration and an increase in erythrocyte mass in both rats and humans. Although this response increases blood oxygen transport capacity, paradoxically, it could impair blood flow and gas exchange because of the blood viscosity alterations associated with the rising hematocrit. In the present study, male rats were subjected to an IHH program consisting of a daily 4-h session for 5 days/week until they had completed 22 days of hypoxia exposure in a hypobaric chamber at a simulated altitude of 5000 m. Blood samples were taken at the end of the exposure period (H) and at 20 (P20) and 40 (P40) days after the end of the program and were compared to control (C) maintained at sea- level pressure. Apparent blood viscosity (eta(a)) and plasma viscosity (eta(p)) were measured in a cone-plate microviscometer. Although the hematocrit significantly increased in the H group, blood apparent viscosity did not differ among groups, ranging from 7.67 to 6.57 mPa*sec at a shear rate of 90 sec(-1). Relative blood viscosity showed a clear increase (about 27%) in H rats, mainly due to the significant decrease in plasma viscosity. This finding could be interpreted as a compensatory response, which reduced the effect of increased erythrocyte mass volume on whole-blood viscosity. Oxygen delivery index and blood oxygen potential transport capacity remained unchanged in all groups. These data indicate that the IHH program has a deep but transitory effect on red cell parameters and a moderate effect on blood rheological behavior.
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Affiliation(s)
- Santiago Esteva
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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18
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Perrey S, Rupp T. Altitude-induced changes in muscle contractile properties. High Alt Med Biol 2009; 10:175-82. [PMID: 19519224 DOI: 10.1089/ham.2008.1093] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Because of its high energetic demand, skeletal muscle is sensitive to changes in the partial pressure of oxygen. Most human studies on in vivo skeletal muscle function during hypoxia were performed with voluntary contractions. However, skeletal muscle function is not only characterized by voluntary maximal or repeated force- generating capacity, but also by force generated by evoked muscle contractions (i.e., force-frequency properties). This mini-review reports on the effects of acute or prolonged exposure to hypoxia on human skeletal muscle performance and contractile properties. The latter depend on both the amount and type of contractile proteins and the efficiency of the cellular mechanism of excitation-contraction coupling. Observations on humans indicate that hypoxia (during simulated ascent or brief exposure) exerts modest influences on the membrane propagation of the muscle action potentials during voluntary contractions. Overall in humans, in physiological conditions, including that of climbing Mt. Everest, there is extraordinarily little that changes with regard to maximal force-generating capacity. Interestingly, it appears that the adaptations to chronic hypoxia minimize the effects on skeletal muscle dysfunction (i.e., impairment during fatigue resistance exercise and in muscle contractile properties) that may occur during acute hypoxia for some isolated muscle exercises. Only sustained isometric exercise exceeding a certain intensity (30% MVC) and causing substantial and sustained ischemia is not affected by acute hypoxia.
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Affiliation(s)
- Stéphane Perrey
- EA 2991 Motor Efficiency and Deficiency Laboratory, Faculty of Sport Sciences, University of Montpellier, 700 Avenue du Pic Saint Loup, 34090 Montpellier, France.
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19
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Wüst RCI, Jaspers RT, van Heijst AF, Hopman MTE, Hoofd LJC, van der Laarse WJ, Degens H. Region-specific adaptations in determinants of rat skeletal muscle oxygenation to chronic hypoxia. Am J Physiol Heart Circ Physiol 2009; 297:H364-74. [PMID: 19429822 DOI: 10.1152/ajpheart.00272.2009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic exposure to hypoxia is associated with muscle atrophy (i.e., a reduction in muscle fiber cross-sectional area), reduced oxidative capacity, and capillary growth. It is controversial whether these changes are muscle and fiber type specific. We hypothesized that different regions of the same muscle would also respond differently to chronic hypoxia. To investigate this, we compared the deep (oxidative) and superficial (glycolytic) region of the plantaris muscle of eight male rats exposed to 4 wk of hypobaric hypoxia (410 mmHg, Po(2): 11.5 kPa) with those of nine normoxic rats. Hematocrit was higher in chronic hypoxic than control rats (59% vs. 50%, P < 0.001). Using histochemistry, we observed 10% fiber atrophy (P < 0.05) in both regions of the muscle but no shift in the fiber type composition and myoglobin concentration of the fibers. In hypoxic rats, succinate dehydrogenase (SDH) activity was elevated in fibers of each type in the superficial region (25%, P < 0.05) but not in the deep region, whereas in the deep region but not the superficial region the number of capillaries supplying a fiber was elevated (14%, P < 0.05). Model calculations showed that the region-specific alterations in fiber size, SDH activity, and capillary supply to a fiber prevented the occurrence of anoxic areas in the deep region but not in the superficial region. Inclusion of reported acclimatization-induced increases in mean capillary oxygen pressure attenuated the development of anoxic tissue areas in the superficial region of the muscle. We conclude that the determinants of tissue oxygenation show region-specific adaptations, resulting in a marked differential effect on tissue Po(2).
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Affiliation(s)
- R C I Wüst
- Institute for Biomedical Research into Human Movement and Health, Manchester Metropolitan University, Manchester, UK.
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CHEN KT, CHEN YY, WU HJ, CHANG CK, LEE WT, LU YY, LIU CC, YANG RS, LIN JC. Decreased anaerobic performance and hormone adaptation after expedition to Peak Lenin. Chin Med J (Engl) 2008. [DOI: 10.1097/00029330-200811020-00004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Panisello P, Torrella JR, Pagés T, Viscor G. Capillary supply and fiber morphometry in rat myocardium after intermittent exposure to hypobaric hypoxia. High Alt Med Biol 2008; 8:322-30. [PMID: 18081508 DOI: 10.1089/ham.2007.1030] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Three groups of male rats were submitted to an intermittent hypobaric hypoxia (IHH) program for 22 days (4 h/day, 5 days/week) in a hypobaric chamber at a simulated altitude of 5000 m. Hearts were removed at the end of the program (H group) and 20 and 40 days later (P20 and P40 groups). A control group (C) was maintained at sea-level pressure. Transverse sections from myocardium were cut and histochemically stained in order to measure fiber morphometry and capillaries. We observed a progressive increase from C to H to P20 animals in capillary (4124 to 4733 to 4816 capillaries/mm(2)) and fiber densities (2844 to 3125 to 3284 fibers/mm(2)) associated with significant reductions in fiber area (273, 235, and 227 microm(2)), perimeter (69, 64, and 62 microm), and diffusion distances (18.2, 16.9, and 16.6 microm). The most significant differences between C and hypoxic groups were found when morphometrical and vascular fiber parameters were combined. The myocardium of the latter had more capillaries per fiber area and per fiber perimeter. These findings indicate that the IHH program elicits an adaptive response of rat myocardium to a more efficient O2 delivery to mitochondria of cardiac muscle cells. Capillarization and fiber morphometric changes showed marked differences over time. In all cases, P20 had higher capillarization parameters and fiber morphometry reductions than H, thus indicating that a delay of about 20 days exists after the hypoxic stimulus ceases to reach complete angiogenesis and fiber morphometry changes. However, P40 animals showed a recovery to basal values of the parameters related to fiber morphometry (area, perimeter, and diffusion distances), but maintained high capillarity values (capillary density, NCF, CCA, CCP).
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Affiliation(s)
- Pere Panisello
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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Hsia CCW, Johnson RL, McDonough P, Dane DM, Hurst MD, Fehmel JL, Wagner HE, Wagner PD. Residence at 3,800-m altitude for 5 mo in growing dogs enhances lung diffusing capacity for oxygen that persists at least 2.5 years. J Appl Physiol (1985) 2007; 102:1448-55. [PMID: 17218427 DOI: 10.1152/japplphysiol.00971.2006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mammals native to high altitude (HA) exhibit larger lung volumes than their lowland counterparts. To test the hypothesis that adaptation induced by HA residence during somatic maturation improves pulmonary gas exchange in adulthood, male foxhounds born at sea level (SL) were raised at HA (3,800 m) from 2.5 to 7.5 mo of age and then returned to SL prior to somatic maturity while their littermates were simultaneously raised at SL. Following return to SL, all animals were trained to run on a treadmill; gas exchange and hemodynamics were measured 2.5 years later at rest and during exercise while breathing 21% and 13% O(2). The multiple inert gas elimination technique was employed to estimate ventilation-perfusion (Va/Q) distributions and lung diffusing capacity for O(2) (Dl(O(2))). There were no significant intergroup differences during exercise breathing 21% O(2). During exercise breathing 13% O(2), peak O(2) uptake and Va/Q distributions were similar between groups but arterial pH, base excess, and O(2) saturation were higher while peak lactate concentration was lower in animals raised at HA than at SL. At a given exercise intensity, alveolar-arterial O(2) tension gradient (A-aDo(2)) attributable to diffusion limitation was lower while Dlo(2) was 12-25% higher in HA-raised animals. Mean systemic arterial blood pressure was also lower in HA-raised animals; mean pulmonary arterial pressures were similar. We conclude that 5 mo of HA residence during maturation enhances long-term gas exchange efficiency and Dl(O(2)) without impacting Va/Q inequality during hypoxic exercise at SL.
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Affiliation(s)
- Connie C W Hsia
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, TX 75390-9034, USA
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23
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Casale R, Farina D, Merletti R, Rainoldi A. Myoelectric manifestations of fatigue during exposure to hypobaric hypoxia for 12 days. Muscle Nerve 2004; 30:618-25. [PMID: 15476258 DOI: 10.1002/mus.20160] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Lack of oxygen, as occurs at high altitude (HA), leads to a number of adaptive processes in muscle, but their precise nature is unclear. To better understand mechanisms of adaptations of the neuromuscular system to HA, we collected surface electromyographic (EMG) signals during a 12-day stay at 5,050 m above sea level (SL). The aim was to investigate the effect of hypobaric hypoxia on muscle-fiber membrane and motor-unit control properties. Surface EMG signals were recorded from the dominant biceps brachii muscle of six subjects at HA and 3 months after their return to SL. Supramaximal electrical stimuli (25 HZ) were delivered and voluntary isometric contractions at 40 and 80% of maximal voluntary torque were performed in 10 experimental sessions at HA and in 3 at SL. Maximal isometric torque was not altered at HA. Surface EMG spectral frequencies at the beginning of the voluntary contractions were greater at HA than SL. The rates of change of spectral frequencies and conduction velocity during the voluntary contractions were significantly larger at HA than SL. No differences in EMG variables were observed in the electrically elicited contractions. The maximal torque and surface EMG variables did not depend on the day of measure at HA. It was concluded that acute exposure to hypobaric hypoxia does not significantly affect the muscle-fiber membrane properties but does impact motor-unit control properties. This provides new insights in the understanding of motor control in extreme conditions of oxygen reduction, with relevance for sport and rehabilitation medicine, and may also explain the pathophysiological adaptations of the neuromuscular system occurring in such disorders as chronic obstructive pulmonary disease.
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Affiliation(s)
- Roberto Casale
- Department of Clinical Neurophysiology, Salvatore Maugeri Foundation, IRCCS, Scientific Institute of Montescano, Italy
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Friedmann B, Kinscherf R, Borisch S, Richter G, Bärtsch P, Billeter R. Effects of low-resistance/high-repetition strength training in hypoxia on muscle structure and gene expression. Pflugers Arch 2003; 446:742-51. [PMID: 12861415 DOI: 10.1007/s00424-003-1133-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2003] [Revised: 05/14/2003] [Accepted: 06/10/2003] [Indexed: 10/26/2022]
Abstract
To test the hypothesis that severe hypoxia during low-resistance/high-repetition strength training promotes muscle hypertrophy, 19 untrained males were assigned randomly to 4 weeks of low-resistance/high-repetition knee extension exercise in either normoxia or in normobaric hypoxia ( FiO(2) 0.12) with recovery in normoxia. Before and after the training period, isokinetic strength tests were performed, muscle cross-sectional area (MCSA) measured (magnetic resonance imaging) and muscle biopsies taken. The significant increase in strength endurance capacity observed in both training groups was not matched by changes in MCSA, fibre type distribution or fibre cross-sectional area. RT-PCR revealed considerable inter-individual variations with no significant differences in the mRNA levels of hypoxia markers, glycolytic enzymes and myosin heavy chain isoforms. We found significant correlations, in the hypoxia group only, for those hypoxia marker and glycolytic enzyme mRNAs that have previously been linked to hypoxia-specific muscle adaptations. This is interpreted as a small, otherwise undetectable adaptation to the hypoxia training condition. In terms of strength parameters, there were, however, no indications that low-resistance/high-repetition training in severe hypoxia is superior to equivalent normoxic training.
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Affiliation(s)
- B Friedmann
- Department of Sports Medicine, Medical Clinic and Policlinic, University of Heidelberg, Im Neuenheimer Feld 710, 69120, Heidelberg, Germany.
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Ferretti G, Berg HE, Minetti AE, Moia C, Rampichini S, Narici MV. Maximal instantaneous muscular power after prolonged bed rest in humans. J Appl Physiol (1985) 2001; 90:431-5. [PMID: 11160038 DOI: 10.1152/jappl.2001.90.2.431] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A reduction in lower limb cross-sectional area (CSA) occurs after bed rest (BR). This should lead to an equivalent reduction in maximal instantaneous muscular power (W(p)) if the body segments' lengths remain unchanged. W(p) was determined during maximal jumps off both feet on a force platform before and on days 2, 6, 10, 32, and 48 after a 42-day duration BR. CSA of thigh muscles was measured by magnetic resonance imaging before and on day 5 after BR. Before BR, W(p) was 3.63 +/- 0.43 kW or 48.6 +/- 3.3 W/kg. On days 2 and 6 after BR, W(p) was reduced by 23.7 +/- 6.9 and 22.7 +/- 5.4% (P < 0.01), respectively. Thigh extensors CSA (CSAEXT) was 16.7 +/- 4.7% (P < 0.01) lower than before. When normalized per CSAEXT, W(p) was reduced by only 4.8 +/- 4.5% (P < 0.05). By day 48 of recovery, W(p) had returned to baseline values. Therefore, if W(p) is appropriately normalized for CSA of the extensor muscles, the reduction in CSAEXT explains most of the decrease in W(p) decrease after BR. Other factors such as a deficit in neural activation or a decrease in fiber-specific tension may account for only 5% of the W(p) loss after BR.
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Affiliation(s)
- G Ferretti
- Département de Physiologie, Centre Médical Universitaire, 1211 Genève 4, Switzerland.
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26
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Imoberdorf R, Garlick PJ, McNurlan MA, Casella GA, Peheim E, Turgay M, Bärtsch P, Ballmer PE. Enhanced synthesis of albumin and fibrinogen at high altitude. J Appl Physiol (1985) 2001; 90:528-37. [PMID: 11160051 DOI: 10.1152/jappl.2001.90.2.528] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The acute effects of active and passive ascent to high altitude on plasma volume (PV) and rates of synthesis of albumin and fibrinogen have been examined. Measurements were made in two groups of healthy volunteers, initially at low altitude (550 m) and again on the day after ascent to high altitude (4,559 m). One group ascended by helicopter (air group, n = 8), whereas the other group climbed (foot group, n = 9), so that the separate contribution of physical exertion to the response could be delineated. PV was measured by dilution of (125)I-labeled albumin, whereas synthesis rates of albumin and fibrinogen were determined from the incorporation of isotope into protein after injection of [ring-(2)H(5)]phenylalanine. In the air group, there was no change in PV at high altitude, whereas, in the foot group, there was a 10% increase in PV (P < 0.01). Albumin synthesis (mg. kg(-1). day(-1)) increased by 13% in the air group (P = 0.058) and by 32% in the foot group (P < 0.001). Fibrinogen synthesis (mg. kg(-1). day(-1)) increased by 40% in the air group (P = 0.068) and by 100% in the foot group (P < 0.001). Hypoxia and alkalosis at high altitude did not differ between the groups. Plasma interleukin-6 was increased modestly in both groups but C-reactive protein was not changed in either group. It is concluded that increases in PV and plasma protein synthesis at high altitude result mainly from the physical exercise associated with climbing. However, a small stimulation of albumin and fibrinogen synthesis may be attributable to hypobaric hypoxia alone.
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Affiliation(s)
- R Imoberdorf
- Department of Internal Medicine, University of Berne, CH-3010 Berne, Switzerland.
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Morris DM, Kearney JT, Burke ER. The effects of breathing supplemental oxygen during altitude training on cycling performance. J Sci Med Sport 2000; 3:165-75. [PMID: 11104308 DOI: 10.1016/s1440-2440(00)80078-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
To compare the training effects of doing high intensity intervals at 1,840 m in a normoxic vs. hyperoxic environment, eight cyclists (NORM) performed intervals on ergometers 3d/wk while breathing normoxic gas (P1O2 = 128 Torr), and seven subjects (HYPER) performed identical intervals at the same relative workload while breathing hyperoxic gas (P1O2 = 156 Torr). HYPER subjects were able to train at a higher percentage of their altitude lactate inflection point than were NORM subjects (HYPER = 126+/-2%, NORM = 109+/-3% p<0.05). Improvements in power output at maximal steady state (NORM = 8 W, HYPER = 20 W,) and improvement in time to complete a 120 kJ cycling performance test (NORM = 2 s, HYPER = 15 s) were significant in the HYPER group pre- vs. post-training (p<0.05) while the NORM group exhibited no significant changes. No significant changes in power output at lactate inflection point were seen in either group (NORM = -12 W, HYPER = +11 W). The results demonstrate that while training at moderate altitude, breathing hyperoxic gas vs. ambient air allows for higher training intensities and this higher intensity training results in significant improvements in maximal steady state power output and time to complete a 120 kJ performance test.
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Affiliation(s)
- D M Morris
- PerforMax: Sports Science Training & Consulting, Colorado Springs, USA
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Narici MV, Kayser B. Hypertrophic response of human skeletal muscle to strength training in hypoxia and normoxia. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1995; 70:213-9. [PMID: 7607195 DOI: 10.1007/bf00238566] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The purpose of this study was to test the hypothesis that work-induced skeletal muscle hypertrophy may be reduced by training in chronic hypobaric hypoxia compared to normoxia. Five healthy males [mean age 34.4 (SEM 2.2) years] performed strength training of the elbow flexors for 1 month, at altitude (A) (5050 m) and with the same absolute loads at sea level (SL), 8 months later. The EF cross-sectional area (CSA), determined at mid-arm by nuclear magnetic resonance imaging, increased by 11.3 (SEM 3.7)% (P < 0.05) at A and 17.7 (SEM 4.5)% (P < 0.05) at SL. Isometric maximal voluntary contraction (MVC) increased by 9.5 (SEM 2.6)% (P < 0.05) at A and 13.6 (SEM 2.4)% (P < 0.05) at SL. The CSA and MVC changes in A were significantly smaller than at SL (P < 0.05). Muscle specific tension did not change in either condition. No changes in muscle plus bone or MVC of the untrained, controlateral arm were observed. Thus, although there was no indication of muscle wasting at A, the hypertrophic response of skeletal muscle when trained in chronic hypoxia seemed to be significantly lower than that produced in normoxia. This effect could have arisen either from a direct depression of protein synthesis and/or hormonal changes provoked by hypoxia.
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Affiliation(s)
- M V Narici
- Istituto di Tecnologie Biomediche Avanzate, Consiglio Nazionale delle Ricerche, Milano, Italy
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Ferretti G, Narici MV, Binzoni T, Gariod L, Le Bas JF, Reutenauer H, Cerretelli P. Determinants of peak muscle power: effects of age and physical conditioning. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1994; 68:111-5. [PMID: 8194538 DOI: 10.1007/bf00244022] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The relationships between absolute peak muscle power (Wpeak), muscle cross sectional area (CSAtot, i.e. the sum of both thigh and calf CSA) and muscle high energy phosphate concentration (adenosine 5'-triphosphate [ATP] and phosphocreatine concentrations [PC]) were studied in 47 subjects classified into five groups: A, 10 sedentary (S) subjects aged 20-35 years; B, 9 S aged 35-50 years; C, 9 S aged more than 50 years; D, 13 children aged 8-13 years; and E, 6 athletes (top level volleyball players) aged 24 (SD 3) years. The Wpeak was measured during a maximal vertical high jump off both feet on a force platform. The CSAtot was measured anthropometrically. The [ATP] and [PC] were determined by 31Phosphorus nuclear magnetic resonance spectroscopy. The Wpeak decreased with age, was 65% lower in D than in A, and 43% higher in E than in A. The CSAtot did not vary with age, was 45% smaller in D than in A, and 15% greater in E than in A. The [ATP] and [PC] were essentially the same in all groups. The changes observed in Wpeak were only partially accounted for by changes in CSAtot. Therefore, in addition to the variables investigated, other factors appear to have been involved in the determination of Wpeak with increasing age and training. An important role may be played by hormonal, particularly at puberty, and neural factors.
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Affiliation(s)
- G Ferretti
- Département de Physiologie, Centre Médical Universitaire, Geneva, Switzerland
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Schena F, Guerrini F, Tregnaghi P, Kayser B. Branched-chain amino acid supplementation during trekking at high altitude. The effects on loss of body mass, body composition, and muscle power. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1992; 65:394-8. [PMID: 1425642 DOI: 10.1007/bf00243503] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To investigate the influence of a branched-chain amino acid (BCAA) supplementation on chronic hypoxia-related loss of body mass and muscle loss, 16 subjects [age 35.8 (SD 5.6) years] participating in a 21-day trek at a mean altitude of 3,255 (SD 458) m, were divided in two age-, sex- and fitness-matched groups and took either a dietary supplementation of BCAA (5.76, 2.88 and 2.88 g per day of leucine, isoleucine and valine, respectively) or a placebo (PLAC) in a controlled double-blind manner. Daily energy intake at altitude decreased by 4% in both groups compared with sea level. After altitude exposure both groups showed a significant loss of body mass, 1.7% and 2.8% for BCAA and PLAC, respectively. Fat mass had decreased significantly by 11.7% for BCAA and 10.3% for PLAC, whereas BCAA showed a significantly increased lean mass of 1.5%, as opposed to no change in PLAC. Arm muscle cross-sectional area tended to increase in BCAA, whereas there was a significant decrease of 6.8% in PLAC (P < 0.05 between groups). The same tendency, although not significant, was observed for the thigh muscle cross-sectional area. On the whole it seemed that PLAC had been catabolizing whereas BCAA had been synthesizing muscle tissue. Single jump height from a squatted position showed a similar tendency to increase in both groups. Lower limb maximal power decreased less in BCAA than in PLAC (2.4% vs 7.8%, P < 0.05). We concluded that BCAA supplementation may prevent muscle loss during chronic hypobaric hypoxia.
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Affiliation(s)
- F Schena
- Institute of Human Physiology, University of Verona, Italy
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Abstract
The present paper discusses the factors affecting maximal O2 consumption (VO2max) in hypoxia (4300 m above sea level) along the following lines: 1) In acute hypoxia, the fractional limitation to VO2max imposed by circulatory O2 transport (FQ') is 50%, instead of 70% as in normoxia. This is due to the increase in the blood O2 transport coefficient (beta b) as PO2 decreases, as a consequence of the sigmoidal shape of the O2 dissociation curve of hemoglobin. The remaining 50% is assumed to be equally partitioned between tissue O2 transfer (Ft') and mitochondria O2 utilization (Fm'). 2) In chronic hypoxia, FQ' = 0.45, Ft' = 0.20 and Fm' = 0.35, as a consequence of reduced muscle fiber size and muscle mitochondrial density following acclimatization. 3) The relationship between VO2max and PIO2 in both acute and chronic hypoxia reflects the O2 dissociation curve. 4) Acclimatization to chronic hypoxia does not have the function of preserving VO2max.
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Affiliation(s)
- G Ferretti
- Département de Physiologie, Centre Médical Universitaire, Genève, Switzerland
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