1
|
Huang Z, Yang S, Li C, Xie X, Wang Y. The effects of intermittent hypoxic training on the aerobic capacity of exercisers: a systemic review and meta-analysis. BMC Sports Sci Med Rehabil 2023; 15:174. [PMID: 38115083 PMCID: PMC10731756 DOI: 10.1186/s13102-023-00784-3] [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: 04/18/2023] [Accepted: 12/07/2023] [Indexed: 12/21/2023]
Abstract
OBJECTIVE To systematically review the effects of intermittent hypoxic training on the aerobic capacity of exercisers. METHODS PubMed, Embase, The Cochrane Library, and Web of Science databases were electronically searched to collect studies on the effects of intermittent hypoxic training on the aerobic capacity of exercisers from January 1, 2000, to January 12, 2023. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies. Then, meta-analysis was performed by using Stata SE 16.0 software. RESULTS A total of 19 articles from 27 studies were included. The results of the meta-analysis showed that compared with the control group, the intermittent hypoxic training group had significantly increased maximal oxygen uptake [weighted mean difference = 3.20 (95%CI: 1.33 ~ 5.08)] and hemoglobin [weighted mean difference = 0.25 (95%CI: 0.04 ~ 0.45)]. CONCLUSION Intermittent hypoxic training can significantly improve the aerobic capacity of exercisers. Due to the limited quantity and quality of the included studies, more high-quality studies are needed to verify the above conclusion.
Collapse
Affiliation(s)
- Zhihao Huang
- School of Big Data and Fundamental Sciences, Shandong Institute of Petroleum and Chemical Technology, Dongying, China
| | - Shulin Yang
- School of Big Data and Fundamental Sciences, Shandong Institute of Petroleum and Chemical Technology, Dongying, China
| | - Chunyang Li
- School of Sports Sciences, Nanjing Normal University, Nanjing, China.
| | - Xingchao Xie
- School of Big Data and Fundamental Sciences, Shandong Institute of Petroleum and Chemical Technology, Dongying, China
| | - Yongming Wang
- School of Big Data and Fundamental Sciences, Shandong Institute of Petroleum and Chemical Technology, Dongying, China
| |
Collapse
|
2
|
Bonato G, Goodman S, Tjh L. Physiological and performance effects of live high train low altitude training for elite endurance athletes: A narrative review. Curr Res Physiol 2023; 6:100113. [PMID: 38107789 PMCID: PMC10724230 DOI: 10.1016/j.crphys.2023.100113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 11/10/2023] [Accepted: 11/21/2023] [Indexed: 12/19/2023] Open
Abstract
Altitude training has become an important training application for athletes due its potential for altering physiology and enhancing performance. This practice is commonly used by athletes, with a popular choice being the live high - train low approach. This model recommends that athletes live at high altitude (1250-3000 m), but train at low altitude or sea-level (0-1200 m). Exposure to altitude often leads to hypoxic stress and in turn stimulates changes in total haemoglobin mass, erythropoietin, and soluble transferrin receptors, which alter further underlying physiology. Through enhanced physiology, improved exercise performance may arise through enhancement of the oxygen transport system which is important for endurance events. Previous investigations into the effects of altitude training on exercise performance have been completed in a range of contexts, including running, cycling, swimming, and triathlon. Often following a LHTL altitude intervention, athletes realise improvements in maximal oxygen consumption capacity, time trial performance and peak power outputs. Although heterogeneity exists among LHTL methodologies, i.e., exposure durations and altitude ranges, we synthesised this data into kilometre hours, and found that the most common hypoxic doses used in LHTL interventions ranged from ∼578-687 km h. As this narrative review demonstrates, there are potential advantages to using altitude training to enhance physiology and improve performance for endurance athletes.
Collapse
Affiliation(s)
- G. Bonato
- Exercise and Sports Science, School of Science and Technology, The University of New England, Armidale, 2350, Australia
- College of Arts, Society and Education, James Cook University, Townsville, 4811, Australia
| | - S.P.J Goodman
- Exercise and Sports Science, School of Science and Technology, The University of New England, Armidale, 2350, Australia
| | - Lathlean Tjh
- Exercise and Sports Science, School of Science and Technology, The University of New England, Armidale, 2350, Australia
- The Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, 5000, Australia
- South Australian Health and Medical Research Institute (SAHMRI), Adelaide, 5000, Australia
| |
Collapse
|
3
|
Giovanna M, Solsona R, Sanchez AMJ, Borrani F. Effects of short-term repeated sprint training in hypoxia or with blood flow restriction on response to exercise. J Physiol Anthropol 2022; 41:32. [PMID: 36057591 PMCID: PMC9440585 DOI: 10.1186/s40101-022-00304-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 08/06/2022] [Indexed: 11/10/2022] Open
Abstract
AbstractThis study compared the effects of a brief repeated sprint training (RST) intervention performed with bilateral blood flow restriction (BFR) conditions in normoxia or conducted at high levels of hypoxia on response to exercise. Thirty-nine endurance-trained athletes completed six repeated sprints cycling sessions spread over 2 weeks consisting of four sets of five sprints (10-s maximal sprints with 20-s active recovery). Athletes were assigned to one of the four groups and subjected to a bilateral partial blood flow restriction (45% of arterial occlusion pressure) of the lower limbs during exercise (BFRG), during the recovery (BFRrG), exercised in a hypoxic room simulating hypoxia at FiO2 ≈ 13% (HG) or were not subjected to additional stress (CG). Peak aerobic power during an incremental test, exercise duration, maximal accumulated oxygen deficit and accumulated oxygen uptake (VO2) during a supramaximal constant-intensity test were improved thanks to RST (p < 0.05). No significant differences were observed between the groups (p > 0.05). No further effect was found on other variables including time-trial performance and parameters of the force-velocity relationship (p > 0.05). Thus, peak aerobic power, exercise duration, maximal accumulated oxygen deficit, and VO2 were improved during a supramaximal constant-intensity exercise after six RST sessions. However, combined hypoxic stress or partial BFR did not further increase peak aerobic power.
Collapse
|
4
|
Albertus-Cámara I, Ferrer-López V, Martínez-González-Moro I. The Effect of Normobaric Hypoxia in Middle- and/or Long-Distance Runners: Systematic Review. BIOLOGY 2022; 11:689. [PMID: 35625417 PMCID: PMC9138601 DOI: 10.3390/biology11050689] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The use of normobaric hypoxia can bring benefits to sports performance because it improves haematological parameters and/or physical activity tests. Our objective was to conduct a systematic review so as to analyse the methods used in hypoxia and to detect its effects on middle- and/or long-distance runners. METHODS Research was conducted using five electronic databases (PubMed, SportDiscus, Cochrane Library, Scopus and PEDro) until December 2021. The methodological quality of the included studies was assessed using the PEDro scale. RESULTS Having analysed 158 studies, 12 were chosen for the qualitative and quantitative synthesis. A significant improvement on time until exhaustion was detected, and oxygen saturation decreased after the intervention. There were no significant changes in the 3000-metre time trial or in the haematocrit percentage. The changes in percentage of reticulocytes, heart rate, maximal heart rate, lactate concentration and erythropoietin were heterogeneous between the different research studies. CONCLUSION short exposure (less than 3 h to normobaric hypoxia significantly increases the time to exhaustion). However, longer exposure times are necessary to increase haemoglobin. Altitude and exposure time are highly heterogeneous in the included studies.
Collapse
Affiliation(s)
| | | | - Ignacio Martínez-González-Moro
- Research Group of Physical Exercise and Human Performance, Mare Nostrum Campus, University of Murcia, 30100 Murcia, Spain; (I.A.-C.); (V.F.-L.)
| |
Collapse
|
5
|
Analysis of Reasonable Respiratory Efficiency in Tennis Competition and Training Environment Based on Cloud Computing. JOURNAL OF HEALTHCARE ENGINEERING 2022; 2022:4289667. [PMID: 35480156 PMCID: PMC9038377 DOI: 10.1155/2022/4289667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 01/19/2022] [Accepted: 03/11/2022] [Indexed: 11/23/2022]
Abstract
Competitive tennis is developing in the direction of quantification. How to use and give full play to all positive factors, in order to attack actively and give full play to the limits of body and psychology, breathing, as the basic metabolic function of human body, also plays a vital role in tennis. This paper studies that it plays an important role in the rationality and explosiveness of sports and the psychological and physiological regulation in competition. The characteristics of tennis events determine the importance of scientific and rational breathing. Reasonable breathing during exercise is conducive to maintaining the basic stability of the internal environment, improving the training effect, and giving full play to the functional ability of the human body, so as to create excellent sports results. First, reduce respiratory resistance. Second, there are two methods to improve alveolar ventilation efficiency and pulmonary ventilation: increasing respiratory rate and increasing respiratory depth. When the inhalation volume is constant, the alveolar gas freshness rate depends on the functional residual volume in the alveolar cavity at the end of expiratory or before inhalation. The less functional the residual air, the more fresh air inhaled, and the higher the oxygen partial pressure in alveolar gas. An effective way to reduce the functional residual volume in the alveolar cavity is to exhale as deeply as possible, so as to ensure that more oxygen enters the body. Reasonable breathing methods can not only accelerate the excitation of the body, increase movement strength, reduce fatigue, and promote recovery but also play a vital role in the rational allocation of physical fitness and the improvement of sports performance. The purpose of this study is to provide a theoretical basis for scientific tennis training by analyzing the characteristics of tennis events, the form of breathing in tennis and the efficiency of reasonable breathing in tennis.
Collapse
|
6
|
Sousa A, Viana JL, Milheiro J, Reis VM, Millet GP. Dietary Nitrate Supplementation Is Not Helpful for Endurance Performance at Simulated Altitude Even When Combined With Intermittent Normobaric Hypoxic Training. Front Physiol 2022; 13:839996. [PMID: 35360239 PMCID: PMC8964050 DOI: 10.3389/fphys.2022.839996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
IntroductionTraining intensity and nutrition may influence adaptations to training performed in hypoxia and consequently performance outcomes at altitude. This study investigates if performance at simulated altitude is improved to a larger extent when high-intensity interval training is performed in normobaric hypoxia and if this is potentiated when combined with chronic dietary nitrate (NO3−) supplementation.MethodsThirty endurance-trained male participants were allocated to one of three groups: hypoxia (13% FiO2) + NO3−; hypoxia + placebo; and normoxia (20.9% FiO2) + placebo. All performed 12 cycling sessions (eight sessions of 2*6 × 1 min at severe intensity with 1 min recovery and four sessions of 4*6*10 s all-out with 20 s recovery) during a 4-week period (three sessions/week) with supplementation administered 3–2.5 h before each session. An incremental exhaustion test, a severe intensity exercise bout to exhaustion (Tlim) and a 3 min all-out test (3AOT) in hypoxia (FiO2 = 13%) with pulmonary oxygen uptake (V˙O2), V˙O2 kinetics, and changes in vastus lateralis local O2 saturation (SmO2) measured were completed by each participant before and after training.ResultsIn all tests, performance improved to the same extent in hypoxia and normoxia, except for SmO2 after Tlim (p = 0.04, d = 0.82) and 3AOT (p = 0.03, d = 1.43) which were lower in the two hypoxic groups compared with the normoxic one. Dietary NO3− supplementation did not bring any additional benefits.ConclusionPerformance at simulated altitude was not improved to a larger extent when high-intensity interval training was undertaken in normobaric hypoxic conditions, when compared with normoxic training. Additionally, dietary NO3− supplementation was ineffective in further enhancing endurance performance at simulated altitude.
Collapse
Affiliation(s)
- Ana Sousa
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), Instituto Universitário da Maia (ISMAI), Maia, Portugal
- *Correspondence: Ana Sousa,
| | - João L. Viana
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), Instituto Universitário da Maia (ISMAI), Maia, Portugal
| | - Jaime Milheiro
- CMEP - Exercise Medical Center & Spa, Porto, Portugal
- Olympic Committee of Portugal, Lisbon, Portugal
| | - Vítor M. Reis
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal
| | - Grégoire P. Millet
- ISSUL, Institute of Sport Sciences and Physical Education (ISSEP), University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
7
|
Debevec T, Millet GP, Brocherie F. Do twelve normobaric hypoxic exposures indeed provoke relevant acclimatization for high-altitude workers? INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2021; 65:637-638. [PMID: 33175214 DOI: 10.1007/s00484-020-02049-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 10/15/2020] [Accepted: 11/04/2020] [Indexed: 06/11/2023]
Affiliation(s)
- Tadej Debevec
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia.
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | | |
Collapse
|
8
|
Mukai K, Ohmura H, Takahashi Y, Kitaoka Y, Takahashi T. Four weeks of high-intensity training in moderate, but not mild hypoxia improves performance and running economy more than normoxic training in horses. Physiol Rep 2021; 9:e14760. [PMID: 33611843 PMCID: PMC7897453 DOI: 10.14814/phy2.14760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 11/24/2022] Open
Abstract
We investigated whether horses trained in moderate and mild hypoxia demonstrate greater improvement in performance and aerobic capacity compared to horses trained in normoxia and whether the acquired training effects are maintained after 2 weeks of post‐hypoxic training in normoxia. Seven untrained Thoroughbred horses completed 4 weeks (3 sessions/week) of three training protocols, consisting of 2‐min cantering at 95% maximal oxygen consumption V˙O2max under two hypoxic conditions (H16, FIO2 = 16%; H18, FIO2 = 18%) and in normoxia (N21, FIO2 = 21%), followed by 2 weeks of post‐hypoxic training in normoxia, using a randomized crossover study design with a 3‐month washout period. Incremental treadmill tests (IET) were conducted at week 0, 4, and 6. The effects of time and groups were analyzed using mixed models. Run time at IET increased in H16 and H18 compared to N21, while speed at V˙O2max was increased significantly only in H16. V˙O2max in all groups and cardiac output at exhaustion in H16 and H18 increased after 4 weeks of training, but were not significantly different between the three groups. In all groups, run time, V˙O2max, VV˙O2max, Q˙max, and lactate threshold did not decrease after 2 weeks of post‐hypoxic training in normoxia. These results suggest that 4 weeks of training in moderate (H16), but not mild (H18) hypoxia elicits greater improvements in performance and running economy than normoxic training and that these effects are maintained for 2 weeks of post‐hypoxic training in normoxia.
Collapse
Affiliation(s)
- Kazutaka Mukai
- Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Hajime Ohmura
- Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Yuji Takahashi
- Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Yu Kitaoka
- Kanagawa University, Yokohama, Kanagawa, Japan
| | | |
Collapse
|
9
|
Ambroży T, Maciejczyk M, Klimek AT, Wiecha S, Stanula A, Snopkowski P, Pałka T, Jaworski J, Ambroży D, Rydzik Ł, Cynarski W. The Effects of Intermittent Hypoxic Training on Anaerobic and Aerobic Power in Boxers. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E9361. [PMID: 33327551 PMCID: PMC7765038 DOI: 10.3390/ijerph17249361] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/13/2020] [Accepted: 12/14/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND The aim of the study was to evaluate the effects of intermittent hypoxic training (IHT) on anaerobic and aerobic fitness in elite, national boxers. METHODS The study was conducted over a period of 6 weeks. It comprised 30 national championship boxers, divided into 2 groups: the experimental and control. Both groups performed the same boxing training twice a day (morning and afternoon training). In the afternoon, the experimental group performed training under normobaric conditions in a hypoxic chamber (IHT), while the control group undertook exercise in standard normoxic conditions. In both groups, before and after the 6-week programme, basic anthropometric indices as well as anaerobic (Wingate Test) and aerobic (graded test) fitness were assessed. RESULTS There was a significant increase in anaerobic peak power (988.2 vs. 1011.8 W), mean anaerobic power (741.1 vs. 764.8 W), total work (22.84 vs. 22.39 kJ), and a decrease in fatigue index (20.33 vs. 18.6 W·s-1) as well as time to peak power (5.01 vs. 4.72 s). Such changes were not observed in the control group. In both groups, no significant changes in endurance performance were noted after the training session - peak oxygen uptake did not significantly vary after IHT. CONCLUSIONS Our results have practical application for coaches, as the IHT seems to be effective in improving anaerobic performance among boxers.
Collapse
Affiliation(s)
- Tadeusz Ambroży
- Institute of Sports Sciences, University of Physical Education, 31-571 Kraków, Poland; (T.A.); (J.J.); (D.A.)
| | - Marcin Maciejczyk
- Department of Physiology and Biochemistry, Faculty of Physical Education and Sport, University of Physical Education in Kraków, 31-571 Kraków, Poland; (M.M.); (A.T.K.); (T.P.)
| | - Andrzej T. Klimek
- Department of Physiology and Biochemistry, Faculty of Physical Education and Sport, University of Physical Education in Kraków, 31-571 Kraków, Poland; (M.M.); (A.T.K.); (T.P.)
| | - Szczepan Wiecha
- Department of Rehabilitation, Faculty of Physical Education and Sport in Biała Podlaska, Józef Piłsudski University of Physical Education, 00-809 Warsaw, Poland;
| | - Arkadiusz Stanula
- Institute of Sport Science, The Jerzy Kukuczka Academy of Physical Education, Mikołowska 72A, 40-065 Katowice, Poland;
| | - Piotr Snopkowski
- Doctoral School, University of Physical Education in Kraków, 31-571 Kraków, Poland;
| | - Tomasz Pałka
- Department of Physiology and Biochemistry, Faculty of Physical Education and Sport, University of Physical Education in Kraków, 31-571 Kraków, Poland; (M.M.); (A.T.K.); (T.P.)
| | - Janusz Jaworski
- Institute of Sports Sciences, University of Physical Education, 31-571 Kraków, Poland; (T.A.); (J.J.); (D.A.)
| | - Dorota Ambroży
- Institute of Sports Sciences, University of Physical Education, 31-571 Kraków, Poland; (T.A.); (J.J.); (D.A.)
| | - Łukasz Rydzik
- Institute of Sports Sciences, University of Physical Education, 31-571 Kraków, Poland; (T.A.); (J.J.); (D.A.)
| | - Wojciech Cynarski
- Institute of Physical Culture Studies, College of Medical Sciences, University of Rzeszów, 35-310 Rzeszów, Poland;
| |
Collapse
|
10
|
Puehringer R, Berger M, Said M, Burtscher M. Age-Dependent Health Status and Cardiorespiratory Fitness in Austrian Military Mountain Guides. High Alt Med Biol 2020; 21:346-351. [PMID: 32757956 DOI: 10.1089/ham.2020.0092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Puehringer, Reinhard, Martin Berger, Michael Said, and Martin Burtscher. Age-dependent health status and cardiorespiratory fitness in Austrian military mountain guides. High Alt Med Biol. 21:346-351, 2020. Background: Mountaineering activities (at moderate and high altitudes) require a relatively high level of physical fitness, which may be closely associated with healthy aging. This cross-sectional study was aimed at evaluating the age-dependent health status and fitness level in Austrian military mountain guides. Methods: A total of 166 professional mountain guides were recruited for a comprehensive health check and exercise testing. Comparisons were made between 3 different age groups, that is, ≤40 years (n = 74), 41-50 years (n = 70), and >50 years (n = 22). Besides exercise capacity, anthropometric, biomedical, and cardiorespiratory parameters have been assessed. Results: None of the assessed parameters differed between age group 1 and 2. A slight increase was observed in the age group 3 concerning body weight, body mass index, blood lipids, blood glucose, and urea levels, and resting systemic blood pressure values. Peak aerobic capacity and maximal heart rates were slightly lower in this age group than the younger groups. When compared with the general population, mountain guides of similar age showed lower prevalence of being overweight, and suffering from systemic hypertension and diabetes. Conclusions: Our findings indicate favorable aging of mountain guides occupationally performing mountaineering activities (at moderate and high altitudes), characterized by maintaining a high fitness level and developing reduced cardiovascular risk factors until older than 50 years.
Collapse
Affiliation(s)
- Reinhard Puehringer
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria.,Austrian Society for Alpine and Mountain Medicine, Innsbruck, Austria
| | - Martin Berger
- Department of Medicine, Military Hospital Innsbruck, Innsbruck, Austria
| | - Michael Said
- Department of Medicine, Military Hospital Innsbruck, Innsbruck, Austria
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria.,Austrian Society for Alpine and Mountain Medicine, Innsbruck, Austria
| |
Collapse
|
11
|
Gangwar A, Paul S, Ahmad Y, Bhargava K. Intermittent hypoxia modulates redox homeostasis, lipid metabolism associated inflammatory processes and redox post-translational modifications: Benefits at high altitude. Sci Rep 2020; 10:7899. [PMID: 32404929 PMCID: PMC7220935 DOI: 10.1038/s41598-020-64848-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 04/09/2020] [Indexed: 01/27/2023] Open
Abstract
Intermittent hypoxia, initially associated with adverse effects of sleep apnea, has now metamorphosed into a module for improved sports performance. The regimen followed for improved sports performance is milder intermittent hypoxic training (IHT) as compared to chronic and severe intermittent hypoxia observed in sleep apnea. Although several studies have indicated the mechanism and enough data on physiological parameters altered by IH is available, proteome perturbations remain largely unknown. Altitude induced hypobaric hypoxia is known to require acclimatization as it causes systemic redox stress and inflammation in humans. In the present study, a short IHT regimen consisting of previously reported physiologically beneficial FIO2 levels of 13.5% and 12% was administered to human subjects. These subjects were then airlifted to altitude of 3500 m and their plasma proteome along with associated redox parameters were analyzed on days 4 and 7 of high altitude stay. We observed that redox stress and associated post-translational modifications, perturbed lipid metabolism and inflammatory signaling were induced by IHT exposure at Baseline. However, this caused activation of antioxidants, energy homeostasis mechanisms and anti-inflammatory responses during subsequent high-altitude exposure. Thus, we propose IHT as a beneficial non-pharmacological intervention that benefits individuals venturing to high altitude areas.
Collapse
Affiliation(s)
- Anamika Gangwar
- Peptide and Proteomics Division, Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi, 110054, India
| | - Subhojit Paul
- Peptide and Proteomics Division, Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi, 110054, India
| | - Yasmin Ahmad
- Peptide and Proteomics Division, Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi, 110054, India.
| | - Kalpana Bhargava
- Peptide and Proteomics Division, Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi, 110054, India.
| |
Collapse
|
12
|
Kasperska A, Zembron-Lacny A. The effect of intermittent hypoxic exposure on erythropoietic response and hematological variables in elite athletes. Physiol Res 2020; 69:283-290. [PMID: 32199016 DOI: 10.33549/physiolres.934316] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
This study aimed to evaluate the changes in the erythropoietin level and hematological variables in wrestlers after intermittent hypoxic exposure (IHE). Twelve wrestlers were assigned into two groups: hypoxia (sports training combined with IHE, n=6) and control (sports training, n=6). An IHE was performed for 10 days, with one day off after 6 days, once a day for about an hour. The concentrations of hydrogen peroxide ( H(2)O(2) ), nitric oxide (NO), vascular endothelial growth factor (VEGF) and erythropoietin (EPO), as well as total creatine kinase activity (CK) were measured. Also, the hematological markers (Hb - hemoglobin, Ht - hematocrit, RBC - red blood cell, WBC - white blood cell, Ret - reticulocytes) were analyzed. The 6-day IHE caused an increase in the levels of H(2)O(2), NO and VEGF. Similarly, the EPO level and WBC count reached the highest value after 6 days of IHE. The total Ret number increase constantly during 10 days of IHE. The hypoxia group showed a higher CK activity compared to the control. In conclusion, 10-day IHE in combination with wrestling training elevates levels of H(2)O(2), NO and VEGF, and improves the oxygen transport capacity by the release of EPO and Ret in circulation.
Collapse
Affiliation(s)
- A Kasperska
- Poznan University of Physical Education, Faculty of Physical Culture in Gorzów Wielkopolski, Poland.
| | | |
Collapse
|
13
|
Płoszczyca K, Foltyn J, Goliniewski J, Krȩżelok J, Poprzȩcki S, Ozimek M, Czuba M. Seasonal changes in gross efficiency and aerobic capacity in well-trained road cyclists. ISOKINET EXERC SCI 2019. [DOI: 10.3233/ies-192115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
| | - Jakub Foltyn
- Department of Sports Training, The Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education, Katowice, Poland
| | - Jakub Goliniewski
- Department of Sports Training, The Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education, Katowice, Poland
| | - Janusz Krȩżelok
- Department of Individual Sports, The Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education, Katowice, Poland
| | - Stanisław Poprzȩcki
- Department of Biochemistry, The Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education, Katowice, Poland
| | | | - Miłosz Czuba
- Department of Kinesiology, Institute of Sport, Warsaw, Poland
| |
Collapse
|
14
|
Recent Data on Cellular Component Turnover: Focus on Adaptations to Physical Exercise. Cells 2019; 8:cells8060542. [PMID: 31195688 PMCID: PMC6627613 DOI: 10.3390/cells8060542] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 05/31/2019] [Accepted: 06/02/2019] [Indexed: 12/22/2022] Open
Abstract
Significant progress has expanded our knowledge of the signaling pathways coordinating muscle protein turnover during various conditions including exercise. In this manuscript, the multiple mechanisms that govern the turnover of cellular components are reviewed, and their overall roles in adaptations to exercise training are discussed. Recent studies have highlighted the central role of the energy sensor (AMP)-activated protein kinase (AMPK), forkhead box class O subfamily protein (FOXO) transcription factors and the kinase mechanistic (or mammalian) target of rapamycin complex (MTOR) in the regulation of autophagy for organelle maintenance during exercise. A new cellular trafficking involving the lysosome was also revealed for full activation of MTOR and protein synthesis during recovery. Other emerging candidates have been found to be relevant in organelle turnover, especially Parkin and the mitochondrial E3 ubiquitin protein ligase (Mul1) pathways for mitochondrial turnover, and the glycerolipids diacylglycerol (DAG) for protein translation and FOXO regulation. Recent experiments with autophagy and mitophagy flux assessment have also provided important insights concerning mitochondrial turnover during ageing and chronic exercise. However, data in humans are often controversial and further investigations are needed to clarify the involvement of autophagy in exercise performed with additional stresses, such as hypoxia, and to understand the influence of exercise modality. Improving our knowledge of these pathways should help develop therapeutic ways to counteract muscle disorders in pathological conditions.
Collapse
|
15
|
Fryer S, Stone K, Dickson T, Wilhelmsen A, Cowen D, Faulkner J, Lambrick D, Stoner L. The effects of 4 weeks normobaric hypoxia training on microvascular responses in the forearm flexor. J Sports Sci 2018; 37:1235-1241. [PMID: 30558476 DOI: 10.1080/02640414.2018.1554177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Intermittent exposure to hypoxia can lead to improved endurance performance. Currently, it is unclear whether peripheral adaptions play a role in improving oxygen delivery and utilization following both training and detraining. This study aimed to characterize skeletal muscle blood flow (mBF), oxygen consumption (mV̇O2), and perfusion adaptations to i) 4-weeks handgrip training in hypoxic and normoxic conditions, and ii) following 4-weeks detraining. Using a randomised crossover design, 9 males completed 30-min handgrip training four times a week in hypoxic (14% FiO2 ~ 3250m altitude) and normoxic conditions. mBF, mV̇O2 and perfusion were assessed pre, post 4-weeks training, and following 4-weeks detraining. Hierarchical linear modelling found that mV̇O2 increased at a significantly faster rate (58%) with hypoxic training (0.09 mlO2·min-1 · 100g-1 per week); perfusion increased at a significantly (69%) faster rate with hypoxic training (3.72 μM per week). mBF did not significantly change for the normoxic condition, but there was a significant increase of 0.38 ml· min-1 · 100ml-1 per week (95% CI: 0.35, 0.40) for the hypoxic condition. During 4-weeks detraining, mV̇O2 and perfusion significantly declined at similar rates for both conditions, whereas mBF decreased significantly faster following hypoxic training. Four weeks hypoxic training increases the delivery and utilisation of oxygen in the periphery.
Collapse
Affiliation(s)
- S Fryer
- a School of Sport and Exercise , University of Gloucestershire , Gloucester , UK
| | - K Stone
- a School of Sport and Exercise , University of Gloucestershire , Gloucester , UK
| | - T Dickson
- a School of Sport and Exercise , University of Gloucestershire , Gloucester , UK
| | - A Wilhelmsen
- b School of Life Sciences, Metabolic and Molecular Physiology Research Group , University of Nottingham , UK
| | - D Cowen
- a School of Sport and Exercise , University of Gloucestershire , Gloucester , UK
| | - J Faulkner
- c Faculty of Business, Law and Sport , University of Winchester , Winchester , UK
| | - D Lambrick
- d Faculty of Health Sciences , University of Southampton , Southampton , UK
| | - L Stoner
- e Department of Sport and Exercise , University of North Carolina , Chapel Hill , NC , USA
| |
Collapse
|
16
|
Sotiridis A, Debevec T, McDonnell AC, Ciuha U, Eiken O, Mekjavic IB. Exercise cardiorespiratory and thermoregulatory responses in normoxic, hypoxic, and hot environment following 10-day continuous hypoxic exposure. J Appl Physiol (1985) 2018; 125:1284-1295. [DOI: 10.1152/japplphysiol.01114.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We examined the effects of acclimatization to normobaric hypoxia on aerobic performance and exercise thermoregulatory responses under normoxic, hypoxic, and hot conditions. Twelve men performed tests of maximal oxygen uptake (V̇O2max) in normoxic (NOR), hypoxic [HYP; 13.5% fraction of inspired oxygen (FiO2)], and hot (HE; 35°C, 50% relative humidity) conditions in a randomized manner before and after a 10-day continuous normobaric hypoxic exposure [FiO2 = 13.65 (0.35)%, inspired partial pressure of oxygen = 87 (3) mmHg]. The acclimatization protocol included daily exercise [60 min at 50% hypoxia-specific peak power output (Wpeak)]. All maximal tests were preceded by a steady-state exercise (30 min at 40% Wpeak) to assess the sweating response. Hematological data were assessed from venous blood samples obtained before and after acclimatization. V̇o2max increased by 10.7% ( P = 0.002) and 7.9% ( P = 0.03) from pre-acclimatization to post acclimatization in NOR and HE, respectively, whereas no differences were found in HYP [pre: 39.9 (3.8) vs. post: 39.4 (5.1) ml·kg−1·min−1, P = 1.0]. However, the increase in V̇O2max did not translate into increased Wpeak in either NOR or HE. Maximal heart rate and ventilation remained unchanged following acclimatization. Νo differences were noted in the sweating gain and thresholds independent of the acclimatization or environmental conditions. Hypoxic acclimatization markedly increased hemoglobin ( P < 0.001), hematocrit ( P < 0.001), and extracellular HSP72 ( P = 0.01). These data suggest that 10 days of normobaric hypoxic acclimatization combined with moderate-intensity exercise training improves V̇o2max in NOR and HE, but does not seem to affect exercise performance or thermoregulatory responses in any of the tested environmental conditions. NEW & NOTEWORTHY The potential crossover effect of hypoxic acclimatization on performance in the heat remains unexplored. Here we show that 10-day continuous hypoxic acclimatization combined with moderate-intensity exercise training can increase maximal oxygen uptake in hot conditions.
Collapse
Affiliation(s)
- Alexandros Sotiridis
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
- Jozef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Adam C. McDonnell
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Urša Ciuha
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Ola Eiken
- Department of Environmental Physiology, School of Chemistry, Biotechnology and Health, Royal Institute of Technology, Solna, Sweden
| | - Igor B. Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| |
Collapse
|
17
|
Low-Frequency Intermittent Hypoxia Promotes Subcutaneous Adipogenic Differentiation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:4501757. [PMID: 29721149 PMCID: PMC5867560 DOI: 10.1155/2018/4501757] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 12/13/2017] [Accepted: 12/24/2017] [Indexed: 12/28/2022]
Abstract
Obstructive sleep apnea (OSA), characterized by intermittent hypoxia (IH), is associated with obesity and metabolic disorders. The mass and function of adipose tissue are largely dependent on adipogenesis. The impact of low-frequency IH on adipogenesis is unknown. Sprague-Dawley rats were subjected to IH (4 min for 10% O2 and 2 min for 21% O2) or intermittent normoxia (IN) for 6 weeks. The degree of adipogenic differentiation was evaluated by adipogenic transcriptional factors, adipocyte-specific proteins, and oily droplet production in both subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT). Upregulation of proadipogenic markers (CEBPα, PPARγ, and FABP4) and downregulation of antiadipogenic markers CHOP in line with smaller size of adipocytes were found in IH-exposed SAT. In vitro experiments using human preadipocytes (HPAs) of subcutaneous lineage during differentiation phase, subjected to IH (1% O2 for 10 min and 21% O2 for 5 min; 5% CO2) or IN treatment, were done to investigate the insulin-like growth factor 1 receptor (IGF-1R)/Akt pathway in adipogenesis. IH promoted the accumulation of oily droplets and adipogenesis-associated markers. IGF-1R kinase inhibitor NVP-AEW541 attenuated the proadipogenic role in IH-exposed HPAs. In summary, relatively low frequency of IH may enhance adipogenesis preferentially in SAT.
Collapse
|
18
|
Sanchez AMJ, Borrani F. Effects of intermittent hypoxic training performed at high hypoxia level on exercise performance in highly trained runners. J Sports Sci 2018; 36:2045-2052. [PMID: 29394148 DOI: 10.1080/02640414.2018.1434747] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
This study exanimated the effects of intermittent hypoxic training (IHT) conducted at a high level of hypoxia with recovery at ambient air on aerobic/anaerobic capacities at sea level and hematological variations. According to a double-blind randomized design, fifteen highly endurance-trained runners completed a 6-weeks regimented training with 3 sessions per week consisting of intermittent runs (6x work-rest ratio of 5':5') on a treadmill at 80-85% of maximal aerobic speed ([Formula: see text]). Nine athletes (hypoxic group, HG) performed the exercise bouts at FI02 = 10.6-11.4% while six athletes (normoxic group, NG) exercised at ambient air. Running time to exhaustion at a velocity corresponding to 95% [Formula: see text] significantly increased for HG while no effect was found for NG. Regarding [Formula: see text], no significant effects were found in either training group. In addition, the decline of jumping performances over a 45s-continuous maximal vertical jump test (i.e. anaerobic capacity index) tended to be lower in HG compared to NG. The levels of the studied hematological variables, including erythropoietin and hematocrit, did not significantly change for either HG or NG. These results highlight that our IHT protocol may induce additional effects on aerobic performance without compromising the anaerobic capacity index in highly-trained athletes.
Collapse
Affiliation(s)
- Anthony M J Sanchez
- a Laboratoire Européen Performance Santé Altitude, EA4604 , University of Perpignan Via Domitia, Department of Sports Sciences , Font-Romeu , France
| | - Fabio Borrani
- b Institute of Sport Sciences of University of Lausanne (ISSUL), Faculty of Biology and Medicine , University of Lausanne , Lausanne , Switzerland
| |
Collapse
|
19
|
Aguilar M, González-Candia A, Rodríguez J, Carrasco-Pozo C, Cañas D, García-Herrera C, Herrera EA, Castillo RL. Mechanisms of Cardiovascular Protection Associated with Intermittent Hypobaric Hypoxia Exposure in a Rat Model: Role of Oxidative Stress. Int J Mol Sci 2018; 19:ijms19020366. [PMID: 29373484 PMCID: PMC5855588 DOI: 10.3390/ijms19020366] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/08/2018] [Accepted: 01/09/2018] [Indexed: 12/25/2022] Open
Abstract
More than 140 million people live and works (in a chronic or intermittent form) above 2500 m worldwide and 35 million live in the Andean Mountains. Furthermore, in Chile, it is estimated that 55,000 persons work in high altitude shifts, where stays at lowlands and interspersed with working stays at highlands. Acute exposure to high altitude has been shown to induce oxidative stress in healthy human lowlanders, due to an increase in free radical formation and a decrease in antioxidant capacity. However, in animal models, intermittent hypoxia (IH) induce preconditioning, like responses and cardioprotection. Here, we aimed to describe in a rat model the responses on cardiac and vascular function to 4 cycles of intermittent hypobaric hypoxia (IHH). Twelve adult Wistar rats were randomly divided into two equal groups, a four-cycle of IHH, and a normobaric hypoxic control. Intermittent hypoxia was induced in a hypobaric chamber in four continuous cycles (1 cycle = 4 days hypoxia + 4 days normoxia), reaching a barometric pressure equivalent to 4600 m of altitude (428 Torr). At the end of the first and fourth cycle, cardiac structural, and functional variables were determined by echocardiography. Thereafter, ex vivo vascular function and biomechanical properties were determined in femoral arteries by wire myography. We further measured cardiac oxidative stress biomarkers (4-Hydroxy-nonenal, HNE; nytrotirosine, NT), reactive oxygen species (ROS) sources (NADPH and mitochondrial), and antioxidant enzymes activity (catalase, CAT; glutathione peroxidase, GPx, and superoxide dismutase, SOD). Our results show a higher ejection and shortening fraction of the left ventricle function by the end of the 4th cycle. Further, femoral vessels showed an improvement of vasodilator capacity and diminished stiffening. Cardiac tissue presented a higher expression of antioxidant enzymes and mitochondrial ROS formation in IHH, as compared with normobaric hypoxic controls. IHH exposure determines a preconditioning effect on the heart and femoral artery, both at structural and functional levels, associated with the induction of antioxidant defence mechanisms. However, mitochondrial ROS generation was increased in cardiac tissue. These findings suggest that initial states of IHH are beneficial for cardiovascular function and protection.
Collapse
Affiliation(s)
- Miguel Aguilar
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
| | - Alejandro González-Candia
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
| | - Jorge Rodríguez
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
- Departamento de Kinesiología, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
| | - Catalina Carrasco-Pozo
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4222, Australia.
- Departamento de Nutrición, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
| | - Daniel Cañas
- Departamento de Ingeniería Mecánica, Facultad de Ingeniería, Universidad de Santiago de Chile, Santiago 9170125, Chile.
| | - Claudio García-Herrera
- Departamento de Ingeniería Mecánica, Facultad de Ingeniería, Universidad de Santiago de Chile, Santiago 9170125, Chile.
| | - Emilio A Herrera
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
- International Center for Andean Studies, Universidad de Chile, Putre, Chile.
| | - Rodrigo L Castillo
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
| |
Collapse
|
20
|
Intermittent hypoxic training for 6 weeks in 3000 m hypobaric hypoxia conditions enhances exercise economy and aerobic exercise performance in moderately trained swimmers. Biol Sport 2017; 35:49-56. [PMID: 30237661 PMCID: PMC6135977 DOI: 10.5114/biolsport.2018.70751] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/22/2017] [Accepted: 06/17/2017] [Indexed: 12/18/2022] Open
Abstract
Athletic endurance performance at sea level can be improved via intermittent hypoxic training (IHT). However, the efficacy of IHT for enhancement of aerobic exercise performance at sea level is controversial because of methodological differences. Therefore, the aim of the study was to determine whether the IHT regimen ameliorates exercise economy and aerobic exercise performance in moderately trained swimmers. A total of 20 moderately trained swimmers were equally assigned to the control group (n=10) training in normoxic conditions and the IHT group (n=10) training at a simulated altitude of 3000 m. They were evaluated for metabolic parameters and skeletal muscle oxygenation during 30 min submaximal exercise on a bicycle, and aerobic exercise performance before and after 6 weeks of training composed of aerobic continuous exercise set at 80% maximal heart rate (HRmax) during 30 min and anaerobic interval exercise set at the exercise load with 90% HRmax measured in pre-test during 30 min (10 times 2 min exercise and 1 min rest). According to the results, the IHT group demonstrated greater improvement in exercise economy due to decreases in VO2 (p=.016) and HHb (p=.002) and increases in O2Hb (p<.001) and TOI (p=.006). VCO2 was decreased in the IHT group (p=.010) and blood lactate level was decreased in the control (p=.005) and IHT groups (p=.001). All aerobic exercise performance including VO2max (p=.001) and the 400 m time trial (p<.001) were increased in the IHT group. The present findings indicate that the 6 week IHT regime composed of high-intensity aerobic continuous exercise and anaerobic interval exercise can be considered an effective altitude/hypoxic training method for improvement of exercise economy and aerobic exercise performance in moderately trained swimmers.
Collapse
|
21
|
Rendell RA, Prout J, Costello JT, Massey HC, Tipton MJ, Young JS, Corbett J. Effects of 10 days of separate heat and hypoxic exposure on heat acclimation and temperate exercise performance. Am J Physiol Regul Integr Comp Physiol 2017; 313:R191-R201. [DOI: 10.1152/ajpregu.00103.2017] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/31/2017] [Accepted: 06/05/2017] [Indexed: 11/22/2022]
Abstract
Adaptations to heat and hypoxia are typically studied in isolation but are often encountered in combination. Whether the adaptive response to multiple stressors affords the same response as when examined in isolation is unclear. We examined 1) the influence of overnight moderate normobaric hypoxia on the time course and magnitude of adaptation to daily heat exposure and 2) whether heat acclimation (HA) was ergogenic and whether this was influenced by an additional hypoxic stimulus. Eight males [V̇o2max = 58.5 (8.3) ml·kg−1·min−1] undertook two 11-day HA programs (balanced-crossover design), once with overnight normobaric hypoxia (HAHyp): 8 (1) h per night for 10 nights [[Formula: see text] = 0.156; SpO2 = 91 (2)%] and once without (HACon). Days 1, 6, and 11 were exercise-heat stress tests [HST (40°C, 50% relative humidity, RH)]; days 2–5 and 7–10 were isothermal strain [target rectal temperature (Tre) ~38.5°C], exercise-heat sessions. A graded exercise test and 30-min cycle trial were undertaken pre-, post-, and 14 days after HA in temperate normoxia (22°C, 55% RH; FIO2 = 0.209). HA was evident on day 6 (e.g., reduced Tre, mean skin temperature (T̄sk), heart rate, and sweat [Na+], P < 0.05) with additional adaptations on day 11 (further reduced T̄sk and heart rate). HA increased plasma volume [+5.9 (7.3)%] and erythropoietin concentration [+1.8 (2.4) mIU/ml]; total hemoglobin mass was unchanged. Peak power output [+12 (20) W], lactate threshold [+15 (18) W] and work done [+12 (20) kJ] increased following HA. The additional hypoxic stressor did not affect these adaptations. In conclusion, a separate moderate overnight normobaric hypoxic stimulus does not affect the time course or magnitude of HA. Performance may be improved in temperate normoxia following HA, but this is unaffected by an additional hypoxic stressor.
Collapse
Affiliation(s)
- Rebecca A. Rendell
- Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Portsmouth, United Kingdom
| | - Jamie Prout
- School of Physical Education, Sport and Exercise Science, Division of Sciences, University of Otago, Dunedin, New Zealand; and
| | - Joseph T. Costello
- Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Portsmouth, United Kingdom
| | - Heather C. Massey
- Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Portsmouth, United Kingdom
| | - Michael J. Tipton
- Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Portsmouth, United Kingdom
| | - John S. Young
- School of Pharmacy and Biomedical Science, Faculty of Science, University of Portsmouth, Portsmouth, United Kingdom
| | - Jo Corbett
- Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Portsmouth, United Kingdom
| |
Collapse
|
22
|
Bayer U, Likar R, Pinter G, Stettner H, Demschar S, Trummer B, Neuwersch S, Glazachev O, Burtscher M. Intermittent hypoxic-hyperoxic training on cognitive performance in geriatric patients. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2017; 3:114-122. [PMID: 29067323 PMCID: PMC5651371 DOI: 10.1016/j.trci.2017.01.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Intermittent hypoxic-hyperoxic training (IHHT) may complement a multimodal training intervention (MTI) for improving cognitive function and exercise tolerance in geriatric patients. METHODS Thirty-four patients (64-92 years) participated in this randomized controlled trial. Before and after the 5- to 7-week intervention period (MTI + IHHT vs. MTI + ambient air), cognitive function was assessed by the Dementia-Detection Test (DemTect) and the Sunderland Clock-Drawing Test (CDT), and functional exercise capacity by the total distance of the 6-Minute Walk Test (6MWT). RESULTS DemTect and CDT indicated significantly larger improvements after MTI + IHHT (+16.7% vs. -0.39%, P < .001) and (+10.7% vs. -8%, P = .031) which was also true for the 6MWT (+24.1% vs. +10.8%, P = .021). DISCUSSION IHHT turned out to be easily applicable to and well tolerated by geriatric patients up to 92 years. IHHT contributed significantly to improvements in cognitive function and functional exercise capacity in geriatric patients performing MTI.
Collapse
Affiliation(s)
- Urike Bayer
- Department of Geriatrics, Klinikum Klagenfurt, Klagenfurt, Austria
| | - Rudolf Likar
- Department of Anesthesiology and Intensive Care Medicine, Klinikum Klagenfurt, Klagenfurt, Austria
| | - Georg Pinter
- Department of Geriatrics, Klinikum Klagenfurt, Klagenfurt, Austria
| | - Haro Stettner
- Department of Statistics, Alpen-Adria University Klagenfurt, Klagenfurt, Austria
| | - Susanne Demschar
- Department of Anesthesiology and Intensive Care Medicine, Klinikum Klagenfurt, Klagenfurt, Austria
| | - Brigitte Trummer
- Department of Anesthesiology and Intensive Care Medicine, Klinikum Klagenfurt, Klagenfurt, Austria
| | - Stefan Neuwersch
- Department of Anesthesiology and Intensive Care Medicine, Klinikum Klagenfurt, Klagenfurt, Austria
| | - Oleg Glazachev
- Research Centre, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Martin Burtscher
- Department of Sport Science, Medical Section, University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
23
|
Nakamoto FP, Ivamoto RK, Andrade MDS, de Lira CAB, Silva BM, da Silva AC. Effect of Intermittent Hypoxic Training Followed by Intermittent Hypoxic Exposure on Aerobic Capacity of Long Distance Runners. J Strength Cond Res 2016; 30:1708-20. [PMID: 26562716 DOI: 10.1519/jsc.0000000000001258] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Effects of intermittent hypoxic training (IHT) are still controversial and detraining effects remain uninvestigated. Therefore, we investigated (a) whether IHT improves aerobic capacity; (b) whether aerobic detraining occurs post-IHT; and (c) whether intermittent hypoxic exposure (IHE) at rest reduces a possible aerobic detraining post-IHT. Twenty eight runners (21 men/7 women; 36 ± 2 years; maximal oxygen uptake [V[Combining Dot Above]O2max] 55.4 ± 1.3 ml·kg·min) participated in a single-blinded placebo-controlled trial. Twice a week, 1 group performed 6 weeks of IHT (n = 11), followed by 4 weeks of IHE (n = 11) at rest (IHT+IHE group). Another group performed 6 weeks of IHT (n = 10), followed by 4 weeks of normoxic exposure (NE, n = 9) at rest (IHT+NE group). A control group performed 6 weeks of normoxic training (NT, n = 7), followed by 4 weeks of NE (n = 6) at rest (NT+NE group). Hematological and submaximal/maximal aerobic measurements were conducted in normoxia at pretraining, posttraining, and postexposure. Hemoglobin concentration did not change, but lactate threshold and running economy improved in all groups at posttraining (p ≤ 0.05 vs. pretraining). Ventilatory threshold, respiratory compensation point, and V[Combining Dot Above]O2max increased after IHT (IHT+IHE group: 7.3, 5.4, and 9.2%, respectively; IHT+NE group: 10.7, 7.5, and 4.8%; p ≤ 0.05 vs. pretraining), but not after NT (-1.1, -1.0, and -3.8%; p > 0.05 vs. pretraining). Such IHT-induced adaptations were maintained at postexposure (p > 0.05 vs. postexposure). In conclusion, IHT induced further aerobic improvements than NT. These additional IHT adaptations were maintained for 4 weeks post-IHT, regardless of IHE.
Collapse
Affiliation(s)
- Fernanda P Nakamoto
- 1Graduate Program in Pharmacology, Federal University of São Paulo, São Paulo, Brazil; 2Olympic Center of Training and Research, São Paulo City Hall, São Paulo, Brazil; 3Department of Physiology, Federal University of São Paulo, São Paulo, Brazil; and 4Section of Human and Exercise Physiology, Faculty of Physical Education and Dance, Federal University of Goiás, Goiânia, Brazil
| | | | | | | | | | | |
Collapse
|
24
|
Park HY, Sunoo S, Nam SS. The Effect of 4 Weeks Fixed and Mixed Intermittent Hypoxic Training (IHT) on Respiratory Metabolic and Acid-base Response of Capillary Blood During Submaximal Bicycle Exercise in Male Elite Taekwondo Players. J Exerc Nutrition Biochem 2016; 20:35-43. [PMID: 28150471 PMCID: PMC5545197 DOI: 10.20463/jenb.2016.0035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
[Purpose] The purpose of our study was to determine the effectiveness of 4 weeks fixed and mixed intermittent hypoxic training (IHT) and its difference from exercise training at sea-level on exercise load, respiratory metabolic and acid-base response of capillary blood during 80% maximal heart rate (HRmax) bicycle exercise in male elite Taekwondo players. [Methods] Male elite Taekwondo players (n = 25 out of 33) were randomly assigned to training at sea-level (n = 8, control group), training at 16.5%O2 (2000 m) simulated hypoxic condition (n = 9, fixed IHT group), and training at 14.5%O2 (3000 m) up to 2 weeks and 16.5%O2 (2000 m) simulated hypoxic condition (n = 8, mixed IHT group) for 3 weeks. We compared their average exercise load, respiratory metabolic, and acid-base response of the capillary blood during 80% HRmax submaximal bicycle exercise before and after 4 weeks training. [Results] Fixed and mixed IHT groups showed positive improvement in respiratory metabolic and acid-base response of the capillary blood during 80% HRmax submaximal bicycle exercise after 4 weeks training. However, all dependent variables showed no significant difference between fixed IHT and mix IHT. [Conclusion] Results suggested that mixed and fixed IHT is effective in improving respiratory metabolic and acid-base response of capillary blood in male elite Taekwondo players. Thus, IHT could be a novel and effective method for improving exercise performance through respiratory metabolic and acid-base response.
Collapse
Affiliation(s)
- Hun-Young Park
- Performance Activity and Performance Institute, Konkuk University, Seoul, Republic of Korea.,Department of Sports Medicine, Kyung Hee University, Yongin-si, Republic of Korea
| | - Sub Sunoo
- Department of Sports Medicine, Kyung Hee University, Yongin-si, Republic of Korea
| | - Sang-Seok Nam
- Department of Sports Medicine, Kyung Hee University, Yongin-si, Republic of Korea
| |
Collapse
|
25
|
Beidleman BA, Fulco CS, Buller MJ, Andrew SP, Staab JE, Muza SR. Quantitative Model of Sustained Physical Task Duration at Varying Altitudes. Med Sci Sports Exerc 2016; 48:323-30. [PMID: 26339725 DOI: 10.1249/mss.0000000000000768] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE The objective of this study is to develop a quantitative model that can be used before ascent to altitude (ALT) to predict how much longer a sustained physical task would take for unacclimatized individuals in the early hours of exposure. METHODS Using multiple linear regression, we analyzed time-trial (TT) performance on 95 unacclimatized men (n = 83) and women (n = 12) at sea level (SL) and at an ALT ranging from 2500 to 4300 m. The TT was initiated within 4 h of ascent to ALT. The independent variables known before ascent were as follows: ALT, age, height, weight, sex, SL peak oxygen uptake, SL task duration time, and body mass index (BMI) classification (normal weight vs overweight). The dependent variable was the percent increase in TT duration from SL to ALT. RESULTS The most significant factor in the model was ALT (P = 0.0001), followed by BMI classification (P = 0.0009) and the interaction between BMI classification and ALT (P = 0.003). The model is as follows: percent increase in TT duration = [100 + e(-1.517+1.323 (ALT)+3.124 (BMI class)-0.769 (ALT) (BMI class)]. The percent increase in TT duration in overweight individuals was 129% greater than for normal-weight individuals at 3000 m. However, as ALT increased beyond 3000 m, the disparity between groups decreased until 4050 m where the percent increase in TT duration became greater for normal-weight individuals. CONCLUSIONS This model provides the first quantitative estimates of the percent increase in sustained physical task duration during initial exposure to a wide range of elevations. Because only two easily obtainable factors are required as inputs for the model (ALT and BMI classification), this model can be used by many unacclimatized individuals to better plan their activities at ALT.
Collapse
Affiliation(s)
- Beth A Beidleman
- 1Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, Natick, MA; and 2Biophysics and Biomedical Modelling Division, United States Army Research Institute of Environmental Medicine, Natick, MA
| | | | | | | | | | | |
Collapse
|
26
|
Baumann CW, Kwak D. Echinacea Supplementation: Does it Really Improve Aerobic Fitness? J Exerc Nutrition Biochem 2016; 20:1-6. [PMID: 27757381 PMCID: PMC5067421 DOI: 10.20463/jenb.2016.09.20.3.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/05/2016] [Accepted: 08/10/2016] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Echinacea is an herbal supplement used by endurance athletes for its performance boosting properties. It is thought that Echinacea improves the blood's oxygen carrying capacity by increasing production of erythropoietin (EPO), a glycoprotein that regulates red blood cell formation. Subsequently, these changes would lead to an overall improvement in maximal oxygen uptake (VO2max) and running economy (RE), two markers of aerobic fitness. The purpose of this review is to briefly discuss the physiological variables associated with distance running performance and how these variables are influenced by Echinacea supplementation. METHODS To determine Echinacea's ergogenic potential, human studies that used Echinacea in conjunction to analyzing the blood's oxygen carrying capacity and/or aerobic fitness were assessed. RESULTS Taken together, the majority of the published literature does not support the claim that Echinacea is a beneficial ergogenic aid. With the exception of one study, several independent groups have reported Echinacea supplementation does not increase EPO production, blood markers of oxygen transport, VO2max or RE in healthy untrained or trained subjects. CONCLUSION To date, the published literature does not support the use of Echinacea as an ergogenic aid to improve aerobic fitness in healthy untrained or trained subjects.
Collapse
Affiliation(s)
- Cory W. Baumann
- Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis, MinnesotaUSA
| | - Dongmin Kwak
- Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis, MinnesotaUSA
| |
Collapse
|
27
|
Turner G, Gibson OR, Watt PW, Pringle JSM, Richardson AJ, Maxwell NS. The time course of endogenous erythropoietin, IL-6, and TNFα in response to acute hypoxic exposures. Scand J Med Sci Sports 2016; 27:714-723. [DOI: 10.1111/sms.12700] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2016] [Indexed: 12/13/2022]
Affiliation(s)
- G. Turner
- Environmental Extremes Laboratory; Centre for Sport and Exercise Science and Medicine (SESAME); University of Brighton; Eastbourne UK
- English Institute of Sport; EIS Performance Centre; Loughborough University; Loughborough UK
| | - O. R. Gibson
- Environmental Extremes Laboratory; Centre for Sport and Exercise Science and Medicine (SESAME); University of Brighton; Eastbourne UK
| | - P. W. Watt
- Environmental Extremes Laboratory; Centre for Sport and Exercise Science and Medicine (SESAME); University of Brighton; Eastbourne UK
| | - J. S. M. Pringle
- English Institute of Sport; EIS Performance Centre; Loughborough University; Loughborough UK
| | - A. J. Richardson
- Environmental Extremes Laboratory; Centre for Sport and Exercise Science and Medicine (SESAME); University of Brighton; Eastbourne UK
| | - N. S. Maxwell
- Environmental Extremes Laboratory; Centre for Sport and Exercise Science and Medicine (SESAME); University of Brighton; Eastbourne UK
| |
Collapse
|
28
|
Willmott AGB, Gibson OR, Hayes M, Maxwell NS. The effects of single versus twice daily short term heat acclimation on heat strain and 3000m running performance in hot, humid conditions. J Therm Biol 2016; 56:59-67. [PMID: 26857978 DOI: 10.1016/j.jtherbio.2016.01.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/04/2016] [Accepted: 01/04/2016] [Indexed: 10/22/2022]
Abstract
Endurance performances are impaired under conditions of elevated heat stress. Short term heat acclimation (STHA) over 4-6 days can evoke rapid adaptation, which mitigate decrements in performance and alleviate heat strain. This study investigated the efficacy of twice daily heat acclimation (TDHA) compared to single session per day heat acclimation (SDHA) and normothermic training, at inducing heat acclimation phenotype and its impact upon running performance in hot, humid conditions. Twenty one, moderately trained males were matched and assigned to three groups; SDHA (mean±SD) (peak oxygen consumption [V̇O2peak] 45.8±6.1mLkg(-1)min(-1), body mass 81.3±16.0kg, stature 182±3cm), TDHA (46.1±7.0mLkg(-1)min(-1), 80.1±11.9kg, 178±4cm) or control (CON) (47.1±3.5mLkg(-1)min(-1), 78.6±16.7kg, 178±4cm). Interventions consisted of 45min cycling at 50% V̇O2peak, once daily for 4d (SDHA) and twice daily for 2d (TDHA), in 35°C, 60% relative humidity (RH), and once daily for 4 days (CON) in 21°C, 40% RH. Participants completed a pre- and post-intervention 5km treadmill run trial in 30°C, 60% RH, where the first 2km were fixed at 40% V̇O2peak and the final 3km was self-paced. No statistically significant interaction effects occurred within- or between-groups over the 2-4 days intervention. While within-group differences were found in physiological and perceptual measures during the fixed intensity trial post-intervention, they did not statistically differ between-groups. Similarly, TDHA (-36±34s [+3.5%]) and SDHA (-26±28s [+2.8%]) groups improved 3km performances (p=0.35), but did not differ from CON (-6±44s [+0.6%]). This is the first study to investigate the effects of HA twice daily and compare it with traditional single session per day STHA. These STHA protocols may have the ability to induce partial adaptive responses to heat stress and possibly enhance performance in environmentally challenging conditions, however, future development is warranted to optimise the administration to provide a potent stimuli for heat adaptation in athletic and military personnel within a rapid regime.
Collapse
Affiliation(s)
- A G B Willmott
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK.
| | - O R Gibson
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK; Centre for Sports Medicine and Human Performance (CSMHP), Brunel University, London, UK
| | - M Hayes
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
| | - N S Maxwell
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
| |
Collapse
|
29
|
Farías JG, Herrera EA, Carrasco-Pozo C, Sotomayor-Zárate R, Cruz G, Morales P, Castillo RL. Pharmacological models and approaches for pathophysiological conditions associated with hypoxia and oxidative stress. Pharmacol Ther 2015; 158:1-23. [PMID: 26617218 DOI: 10.1016/j.pharmthera.2015.11.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hypoxia is the failure of oxygenation at the tissue level, where the reduced oxygen delivered is not enough to satisfy tissue demands. Metabolic depression is the physiological adaptation associated with reduced oxygen consumption, which evidently does not cause any harm to organs that are exposed to acute and short hypoxic insults. Oxidative stress (OS) refers to the imbalance between the generation of reactive oxygen species (ROS) and the ability of endogenous antioxidant systems to scavenge ROS, where ROS overwhelms the antioxidant capacity. Oxidative stress plays a crucial role in the pathogenesis of diseases related to hypoxia during intrauterine development and postnatal life. Thus, excessive ROS are implicated in the irreversible damage to cell membranes, DNA, and other cellular structures by oxidizing lipids, proteins, and nucleic acids. Here, we describe several pathophysiological conditions and in vivo and ex vivo models developed for the study of hypoxic and oxidative stress injury. We reviewed existing literature on the responses to hypoxia and oxidative stress of the cardiovascular, renal, reproductive, and central nervous systems, and discussed paradigms of chronic and intermittent hypobaric hypoxia. This systematic review is a critical analysis of the advantages in the application of some experimental strategies and their contributions leading to novel pharmacological therapies.
Collapse
Affiliation(s)
- Jorge G Farías
- Facultad de Ingeniería y Ciencias, Departamento de Ingeniería Química, Universidad de la Frontera, Casilla 54-D, Temuco, Chile
| | - Emilio A Herrera
- Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Chile; International Center for Andean Studies (INCAS), Universidad de Chile, Chile
| | | | - Ramón Sotomayor-Zárate
- Centro de Neurobiología y Plasticidad Cerebral (CNPC), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Chile
| | - Gonzalo Cruz
- Centro de Neurobiología y Plasticidad Cerebral (CNPC), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Chile
| | - Paola Morales
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile, Chile
| | - Rodrigo L Castillo
- Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Chile.
| |
Collapse
|
30
|
Abstract
Running economy (RE) represents a complex interplay of physiological and biomechanical factors that is typically defined as the energy demand for a given velocity of submaximal running and expressed as the submaximal oxygen uptake (VO2) at a given running velocity. This review considered a wide range of acute and chronic interventions that have been investigated with respect to improving economy by augmenting one or more components of the metabolic, cardiorespiratory, biomechanical or neuromuscular systems. Improvements in RE have traditionally been achieved through endurance training. Endurance training in runners leads to a wide range of physiological responses, and it is very likely that these characteristics of running training will influence RE. Training history and training volume have been suggested to be important factors in improving RE, while uphill and level-ground high-intensity interval training represent frequently prescribed forms of training that may elicit further enhancements in economy. More recently, research has demonstrated short-term resistance and plyometric training has resulted in enhanced RE. This improvement in RE has been hypothesized to be a result of enhanced neuromuscular characteristics. Altitude acclimatization results in both central and peripheral adaptations that improve oxygen delivery and utilization, mechanisms that potentially could improve RE. Other strategies, such as stretching should not be discounted as a training modality in order to prevent injuries; however, it appears that there is an optimal degree of flexibility and stiffness required to maximize RE. Several nutritional interventions have also received attention for their effects on reducing oxygen demand during exercise, most notably dietary nitrates and caffeine. It is clear that a range of training and passive interventions may improve RE, and researchers should concentrate their investigative efforts on more fully understanding the types and mechanisms that affect RE and the practicality and extent to which RE can be improved outside the laboratory.
Collapse
Affiliation(s)
- Kyle R Barnes
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Level 2, AUT-Millennium Campus, 17 Antares Place, Mairangi Bay, Auckland, New Zealand,
| | | |
Collapse
|
31
|
Chen CY, Hou CW, Bernard JR, Chen CC, Hung TC, Cheng LL, Liao YH, Kuo CH. Rhodiola crenulata- and Cordyceps sinensis-based supplement boosts aerobic exercise performance after short-term high altitude training. High Alt Med Biol 2015; 15:371-9. [PMID: 25251930 DOI: 10.1089/ham.2013.1114] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
High altitude training is a widely used strategy for improving aerobic exercise performance. Both Rhodiola crenulata (R) and Cordyceps sinensis (C) supplements have been reported to improve exercise performance. However, it is not clear whether the provision of R and C during high altitude training could further enhance aerobic endurance capacity. In this study, we examined the effect of R and C based supplementation on aerobic exercise capacity following 2-week high altitude training. Alterations to autonomic nervous system activity, circulatory hormonal, and hematological profiles were investigated. Eighteen male subjects were divided into two groups: Placebo (n=9) and R/C supplementation (RC, n=9). Both groups received either RC (R: 1400 mg+C: 600 mg per day) or the placebo during a 2-week training period at an altitude of 2200 m. After 2 weeks of altitude training, compared with Placebo group, the exhaustive run time was markedly longer (Placebo: +2.2% vs. RC: +5.7%; p<0.05) and the decline of parasympathetic (PNS) activity was significantly prevented in RC group (Placebo: -51% vs. RC: -41%; p<0.05). Red blood cell, hematocrit, and hemoglobin levels were elevated in both groups to a comparable extent after high altitude training (p<0.05), whereas the erythropoietin (EPO) level remained higher in the Placebo group (∼48% above RC values; p<0.05). The provision of an RC supplement during altitude training provides greater training benefits in improving aerobic performance. This beneficial effect of RC treatment may result from better maintenance of PNS activity and accelerated physiological adaptations during high altitude training.
Collapse
Affiliation(s)
- Chung-Yu Chen
- 1 Department of Exercise and Health Sciences, University of Taipei , Taipei, Taiwan
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Álvarez-Herms J, Julià-Sánchez S, Corbi F, Pagès T, Viscor G. Anaerobic performance after endurance strength training in hypobaric environment. Sci Sports 2014. [DOI: 10.1016/j.scispo.2013.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
33
|
Schiffer TA, Ekblom B, Lundberg JO, Weitzberg E, Larsen FJ. Dynamic regulation of metabolic efficiency explains tolerance to acute hypoxia in humans. FASEB J 2014; 28:4303-11. [DOI: 10.1096/fj.14-251710] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tomas A. Schiffer
- Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| | - Björn Ekblom
- Åstrand Laboratory of Work PhysiologySwedish School of Sports and Health SciencesStockholmSweden
| | - Jon O. Lundberg
- Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| | - Eddie Weitzberg
- Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| | - Filip J. Larsen
- Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| |
Collapse
|
34
|
Almendros I, Wang Y, Gozal D. The polymorphic and contradictory aspects of intermittent hypoxia. Am J Physiol Lung Cell Mol Physiol 2014; 307:L129-40. [PMID: 24838748 DOI: 10.1152/ajplung.00089.2014] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Intermittent hypoxia (IH) has been extensively studied during the last decade, primarily as a surrogate model of sleep apnea. However, IH is a much more pervasive phenomenon in human disease, is viewed as a potential therapeutic approach, and has also been used in other disciplines, such as in competitive sports. In this context, adverse outcomes involving cardiovascular, cognitive, metabolic, and cancer problems have emerged in obstructive sleep apnea-based studies, whereas beneficial effects of IH have also been identified. Those a priori contradictory findings may not be as contradictory as initially thought. Indeed, the opposite outcomes triggered by IH can be explained by the specific characteristics of the large diversity of IH patterns applied in each study. The balance between benefits and injury appears to primarily depend on the ability of the organism to respond and activate adaptive mechanisms to IH. In this context, the adaptive or maladaptive responses can be generally predicted by the frequency, severity, and duration of IH. However, the presence of underlying conditions such as hypertension or obesity, as well as age, sex, or genotypic variance, may be important factors tilting the balance between an appropriate homeostatic response and decompensation. Here, the two possible facets of IH as derived from human and experimental animal settings will be reviewed.
Collapse
Affiliation(s)
- Isaac Almendros
- Department of Pediatrics, Comer Children's Hospital, Pritzker School of Medicine, The University of Chicago, Chicago, Illinois
| | - Yang Wang
- Department of Pediatrics, Comer Children's Hospital, Pritzker School of Medicine, The University of Chicago, Chicago, Illinois
| | - David Gozal
- Department of Pediatrics, Comer Children's Hospital, Pritzker School of Medicine, The University of Chicago, Chicago, Illinois
| |
Collapse
|
35
|
Marquez JL, Rubinstein S, Fattor JA, Shah O, Hoffman AR, Friedlander AL. Cyclic hypobaric hypoxia improves markers of glucose metabolism in middle-aged men. High Alt Med Biol 2013; 14:263-72. [PMID: 24028640 DOI: 10.1089/ham.2012.1057] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
UNLABELLED Chronic hypoxia increases dependence on glucose in men and increases insulin sensitivity in men and women. Cyclic Variations in Altitude Conditioning (CVAC) is a novel technology that provides exposure to rapidly fluctuating cyclic hypobaric hypoxia (CHH). PURPOSE To test the hypothesis that markers of glucose metabolism would change with CVAC CHH, two groups of middle-aged men were exposed to 10 weeks (40 min/day, 3 day/week) of either CHH or sham (SH) sessions. METHODS CHH subjects (age: 48 ± 6, weight: 86 ± 12 kg, BMI: 27.1 ± 3, n=11) experienced cyclic pressures simulating altitudes ranging from sea level to 3048 m (week 1) and progressing to 6096 m (by week 5 through week 10). SH subjects (age: 50 ± 4, weight: 89 ± 15 kg, BMI: 27.5 ± 3, n=10) were exposed to slowly-fluctuating pressures up to 607 m (all subjects blinded to elevation). Physical function and blood markers of glucose metabolism were measured at baseline, 3, 6, and 10 weeks. RESULTS Two CHH subjects were dropped from analysis for failure to progress past 3048 m (CHH: n=9). Weight and physical activity remained stable for both groups. There was a group-by-time interaction in fasting glucose (CHH: 96 ± 9 to 91 ± 7 mg/dL, SH: 94 ± 7 to 97 ± 9 mg/dL, p<0.05). Reduction in plasma glucose response to oral glucose tolerance test [area under the curve] was greater in CHH compared to SH after 10 weeks of exposure (p<0.03). Neither group experienced changes in fasting insulin, insulin response during the OGTT, or changes in a timed walk test. CONCLUSION Ten weeks of CVAC CHH exposure improves markers of glucose metabolism in middle-aged men at risk for metabolic syndrome.
Collapse
Affiliation(s)
- Juan L Marquez
- 1 Clinical Studies Unit, VA Palo Alto Health Care System , Palo Alto, California
| | | | | | | | | | | |
Collapse
|
36
|
Billaut F, Gore CJ, Aughey RJ. Enhancing team-sport athlete performance: is altitude training relevant? Sports Med 2013; 42:751-67. [PMID: 22845561 DOI: 10.1007/bf03262293] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Field-based team sport matches are composed of short, high-intensity efforts, interspersed with intervals of rest or submaximal exercise, repeated over a period of 60-120 minutes. Matches may also be played at moderate altitude where the lower oxygen partial pressure exerts a detrimental effect on performance. To enhance run-based performance, team-sport athletes use varied training strategies focusing on different aspects of team-sport physiology, including aerobic, sprint, repeated-sprint and resistance training. Interestingly, 'altitude' training (i.e. living and/or training in O(2)-reduced environments) has only been empirically employed by athletes and coaches to improve the basic characteristics of speed and endurance necessary to excel in team sports. Hypoxia, as an additional stimulus to training, is typically used by endurance athletes to enhance performance at sea level and to prepare for competition at altitude. Several approaches have evolved in the last few decades, which are known to enhance aerobic power and, thus, endurance performance. Altitude training can also promote an increased anaerobic fitness, and may enhance sprint capacity. Therefore, altitude training may confer potentially-beneficial adaptations to team-sport athletes, which have been overlooked in contemporary sport physiology research. Here, we review the current knowledge on the established benefits of altitude training on physiological systems relevant to team-sport performance, and conclude that current evidence supports implementation of altitude training modalities to enhance match physical performances at both sea level and altitude. We hope that this will guide the practice of many athletes and stimulate future research to better refine training programmes.
Collapse
Affiliation(s)
- François Billaut
- School of Sport and Exercise Science, Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, VIC, Australia.
| | | | | |
Collapse
|
37
|
Stowe AM, Wacker BK, Cravens PD, Perfater JL, Li MK, Hu R, Freie AB, Stüve O, Gidday JM. CCL2 upregulation triggers hypoxic preconditioning-induced protection from stroke. J Neuroinflammation 2012; 9:33. [PMID: 22340958 PMCID: PMC3298779 DOI: 10.1186/1742-2094-9-33] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 02/16/2012] [Indexed: 02/04/2023] Open
Abstract
Background A brief exposure to systemic hypoxia (i.e., hypoxic preconditioning; HPC) prior to transient middle cerebral artery occlusion (tMCAo) reduces infarct volume, blood-brain barrier disruption, and leukocyte migration. CCL2 (MCP-1), typically regarded as a leukocyte-derived pro-inflammatory chemokine, can also be directly upregulated by hypoxia-induced transcription. We hypothesized that such a hypoxia-induced upregulation of CCL2 is required for HPC-induced ischemic tolerance. Methods Adult male SW/ND4, CCL2-null, and wild-type mice were used in these studies. Cortical CCL2/CCR2 message, protein, and cell-type specific immunoreactivity were determined following HPC (4 h, 8% O2) or room air control (21% O2) from 6 h through 2 weeks following HPC. Circulating leukocyte subsets were determined by multi-parameter flow cytometry in naïve mice and 12 h after HPC. CCL2-null and wild-type mice were exposed to HPC 2 days prior to tMCAo, with immunoneutralization of CCL2 during HPC achieved by a monoclonal CCL2 antibody. Results Cortical CCL2 mRNA and protein expression peaked at 12 h after HPC (both p < 0.01), predominantly in cortical neurons, and returned to baseline by 2 days. A delayed cerebral endothelial CCL2 message expression (p < 0.05) occurred 2 days after HPC. The levels of circulating monocytes (p < 0.0001), T lymphocytes (p < 0.0001), and granulocytes were decreased 12 h after HPC, and those of B lymphocytes were increased (p < 0.0001), but the magnitude of these respective changes did not differ between wild-type and CCL2-null mice. HPC did decrease the number of circulating CCR2+ monocytes (p < 0.0001) in a CCL2-dependent manner, but immunohistochemical analyses at this 12 h timepoint indicated that this leukocyte subpopulation did not move into the CNS. While HPC reduced infarct volumes by 27% (p < 0.01) in wild-type mice, CCL2-null mice subjected to tMCAo were not protected by HPC. Moreover, administration of a CCL2 immunoneutralizing antibody prior to HPC completely blocked (p < 0.0001 vs. HPC-treated mice) the development of ischemic tolerance. Conclusions The early expression of CCL2 in neurons, the delayed expression of CCL2 in cerebral endothelial cells, and CCL2-mediated actions on circulating CCR2+ monocytes, appear to be required to establish ischemic tolerance to focal stroke in response to HPC, and thus represent a novel role for this chemokine in endogenous neurovascular protection.
Collapse
Affiliation(s)
- Ann M Stowe
- Department of Neurological Surgery, Washington University School of Medicine, 660 S, Euclid Ave,, Box 8057, St, Louis, MO 63110, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Siebenmann C, Robach P, Jacobs RA, Rasmussen P, Nordsborg N, Diaz V, Christ A, Olsen NV, Maggiorini M, Lundby C. "Live high-train low" using normobaric hypoxia: a double-blinded, placebo-controlled study. J Appl Physiol (1985) 2011; 112:106-17. [PMID: 22033534 DOI: 10.1152/japplphysiol.00388.2011] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The combination of living at altitude and training near sea level [live high-train low (LHTL)] may improve performance of endurance athletes. However, to date, no study can rule out a potential placebo effect as at least part of the explanation, especially for performance measures. With the use of a placebo-controlled, double-blinded design, we tested the hypothesis that LHTL-related improvements in endurance performance are mediated through physiological mechanisms and not through a placebo effect. Sixteen endurance cyclists trained for 8 wk at low altitude (<1,200 m). After a 2-wk lead-in period, athletes spent 16 h/day for the following 4 wk in rooms flushed with either normal air (placebo group, n = 6) or normobaric hypoxia, corresponding to an altitude of 3,000 m (LHTL group, n = 10). Physiological investigations were performed twice during the lead-in period, after 3 and 4 wk during the LHTL intervention, and again, 1 and 2 wk after the LHTL intervention. Questionnaires revealed that subjects were unaware of group classification. Weekly training effort was similar between groups. Hb mass, maximal oxygen uptake (VO(2)) in normoxia, and at a simulated altitude of 2,500 m and mean power output in a simulated, 26.15-km time trial remained unchanged in both groups throughout the study. Exercise economy (i.e., VO(2) measured at 200 W) did not change during the LHTL intervention and was never significantly different between groups. In conclusion, 4 wk of LHTL, using 16 h/day of normobaric hypoxia, did not improve endurance performance or any of the measured, associated physiological variables.
Collapse
Affiliation(s)
- Christoph Siebenmann
- Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Stowe AM, Altay T, Freie AB, Gidday JM. Repetitive hypoxia extends endogenous neurovascular protection for stroke. Ann Neurol 2011; 69:975-85. [PMID: 21437933 DOI: 10.1002/ana.22367] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 12/20/2010] [Accepted: 01/03/2011] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Brief systemic hypoxia protects the rodent brain from subsequent ischemic injury, although the protection wanes within days. We hypothesized that the duration of ischemic tolerance could be extended from days to months by repeated intermittent hypoxia of varying magnitude and duration. METHODS Infarction volumes following a 60-minute transient middle cerebral artery occlusion were determined in adult male mice 2 days through 8 weeks after completion of a 2-week repetitive hypoxic preconditioning (RHP) protocol. Separate cohorts were studied for the protective effects of RHP on postischemic and cytokine-induced cerebrovascular inflammation, and for potential deleterious effects of the RHP stimulus itself. RESULTS RHP protection against transient focal stroke persisted for 8 weeks. Leukocyte adherence to cortical venules was attenuated in response to stroke, as well as following tumor necrosis factor-α administration, indicating that reductions in postischemic inflammation were not secondary to smaller infarct volumes. RHP reduced poststroke leukocyte diapedesis concomitant with a long-lasting downregulation of endothelial adhesion molecule mRNAs, and also reduced postischemic blood--brain barrier permeability to endogenous immunoglobulin G. RHP was without effect on hippocampal CA1 pyramidal cell viability, only transiently elevated hematocrit, and did not affect the magnitude of cerebral blood flow during and after ischemia. INTERPRETATION Taken together, our findings reveal a novel form of epigenetic neurovascular plasticity characterized by a prominent anti-inflammatory phenotype that provides protection against stroke many weeks longer than previously established windows of preconditioning-induced tolerance. Translating these endogenous protective mechanisms into therapeutics could afford sustained periods of cerebroprotection in subpopulations of individuals at identified risk for stroke.
Collapse
Affiliation(s)
- Ann M Stowe
- Department of Neurological Surgery, Washington University School of Medicine, St Louis, MO 63110, USA
| | | | | | | |
Collapse
|
40
|
de Paula P, Niebauer J. Effects of high altitude training on exercise capacity: fact or myth. Sleep Breath 2010; 16:233-9. [DOI: 10.1007/s11325-010-0445-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2010] [Revised: 11/06/2010] [Accepted: 11/09/2010] [Indexed: 11/30/2022]
|
41
|
Beidleman BA, Muza SR, Fulco CS, Jones JE, Lammi E, Staab JE, Cymerman A. Intermittent hypoxic exposure does not improve endurance performance at altitude. Med Sci Sports Exerc 2010; 41:1317-25. [PMID: 19461532 DOI: 10.1249/mss.0b013e3181954601] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study examined the effect of 1 wk of normobaric intermittent hypoxic exposure (IHE) combined with exercise training on endurance performance at a 4300-m altitude (HA). METHODS Seventeen male lowlanders were divided into an IHE (n = 11) or SHAM (n = 6) group. Each completed cycle endurance testing consisting of two 20-min steady state (SS) exercise bouts (at 40% and 60% V O2peak) followed by a 10-min break and then a 720-kJ cycle time trial at HA before IHE or SHAM treatment (Pre-T). IHE treatment consisted of a 2-h rest at a PO2 of 90 mm Hg followed by two 25-min bouts of exercise at approximately 80% of peak HR at a PO2 of 110 mm Hg for 1 wk in a hypoxia room. SHAM treatment was identical except that the PO2 was 148 mm Hg for both rest and exercise. After IHE or SHAM treatment (Post-T), all completed a second cycle endurance test at HA. HR, arterial oxygen saturation (SaO2), and RPE were obtained from the 10th to the 15th minute during the two SS exercise bouts and every 5 min during the time trial. RESULTS Seven volunteers in the IHE group could not finish the 720-kJ time trial either at Pre-T or at Post-T. Time trial analysis was limited, therefore, to the time to reach 360 kJ (halfway point) for all volunteers. From Pre-T to Post-T, there was no improvement in time trial performance (min +/- SE) in the IHE (62.0 +/- 4.8 to 63.7 +/- 5.2) or SHAM (60.9 +/- 6.3 to 54.2 +/- 6.8) group. There was no change from Pre-T to Post-T in HR, SaO2, and RPE during the two SS exercise bouts or time trial in either group. CONCLUSIONS One week of IHE combined with exercise training does not improve endurance performance at a 4300-m altitude in male lowlanders.
Collapse
Affiliation(s)
- Beth A Beidleman
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA 01760, USA.
| | | | | | | | | | | | | |
Collapse
|
42
|
|
43
|
Taylor L, Midgley AW, Chrismas B, Hilman AR, Madden LA, Vince RV, McNaughton LR. Daily hypoxia increases basal monocyte HSP72 expression in healthy human subjects. Amino Acids 2010; 40:393-401. [PMID: 20552383 DOI: 10.1007/s00726-010-0644-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 05/27/2010] [Indexed: 01/19/2023]
Abstract
Heat shock protein 72 (HSP72) performs vital roles within the body at rest and during periods of stress. In vitro, research demonstrates HSP72 induction in response to hypoxia. Recently, in vivo, an acute hypoxic exposure (75 min at 2,980 m) was sufficient to induce significant increases in monocyte expressed HSP72 (mHSP72) and a marker of oxidative stress in healthy human subjects. The purpose of the current study was to identify the impact of 10 consecutive days of hypoxic exposures (75 min at 2,980 m) on mHSP72 and erythropoietin (EPO) expression, markers of oxidative stress, and maximal oxygen consumption in graded incremental aerobic exercise. Eight male subjects were exposed to daily normobaric hypoxic exposures for 75 min at 2,980 m for 10 consecutive days, commencing and ceasing at 0930 and 1045, respectively. This stressor was sufficient to induce significant increases in mHSP72, which was significantly elevated from day 2 of the hypoxic exposures until 48 h post-final exposure. Notably, this increase had an initial rapid (30% day on day compared to baseline) and final slow phase (16% day on day compared to baseline) of expression. The authors postulate that 7-day hypoxic exposure in this manner would be sufficient to induce near maximum hypoxia-mediated basal mHSP72 expression. Elevated levels of mHSP72 are associated with acquired thermotolerance and provide cross tolerance to non-related stressors in vivo, the protocol used here may provide a useful tool for elevating mHSP72 in vivo. Aside from these major findings, significant transient daily elevations were seen in a marker of oxidative stress, alongside sustained increases in EPO expression. However, no physiologically significant changes were seen in maximal oxygen consumption or time to exhaustion.
Collapse
Affiliation(s)
- Lee Taylor
- Department of Sport, Health and Exercise Science, University of Hull, Hull, HU6 7RX, UK
| | | | | | | | | | | | | |
Collapse
|
44
|
Bassovitch O. ‘Combining Hypoxic Methods for Peak Performance’: a Biomedical Engineering Perspective. Sports Med 2010; 40:519-21; author reply 521-3. [DOI: 10.2165/11535150-000000000-00000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
45
|
Hamlin MJ, Marshall HC, Hellemans J, Ainslie PN. Effect of intermittent hypoxia on muscle and cerebral oxygenation during a 20-km time trial in elite athletes: a preliminary report. Appl Physiol Nutr Metab 2010; 35:548-59. [DOI: 10.1139/h10-044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The effects of intermittent hypoxic exposure (IHE) on cerebral and muscle oxygenation, arterial oxygen saturation (SaO2), and respiratory gas exchange during a 20-km cycle time trial (20TT) were examined (n = 9) in a placebo-controlled randomized design. IHE (7:3 min hypoxia to normoxia) involved 90-min sessions for 10 days, with SaO2 clamped at ∼80%. Prior to, and 2 days after the intervention, a 20TT was performed. During the final minute of the 20TT, in the IHE group only, muscle oxyhemoglobin (oxy-Hb) was elevated (mean ± 95% confidence interval 1.3 ± 1.2 ΔµM, p = 0.04), whereas cerebral oxy-Hb was reduced (–1.9% ± 1.0%, p < 0.01) post intervention compared with baseline. The 20TT performance was unchanged between groups (p = 0.7). In the IHE group, SaO2 was higher (1.0 ± 0.7Δ%, p = 0.006) and end-tidal PCO2 was lower (–1.2 ± 0.1 mm Hg, p = 0.01) during the final stage of the 20TT post intervention compared with baseline. In summary, reductions in muscle oxy-Hb and systemic SaO2 occurring at exercise intensities close to maximal at the end of a 20TT were offset by IHE, although this was not translated into improved performance.
Collapse
Affiliation(s)
- Michael J. Hamlin
- Department of Social Science, Parks, Recreation, Tourism, and Sport, Environment Society and Design Division, P.O. Box 84, Lincoln University, Canterbury 7647, New Zealand
- New Zealand Academy of Sport, Dunedin, New Zealand
- Department of Human Kinetics, University of British Columbia Okanagan, Kelowna, BC V6T 1Z1, Canada
| | - Helen C. Marshall
- Department of Social Science, Parks, Recreation, Tourism, and Sport, Environment Society and Design Division, P.O. Box 84, Lincoln University, Canterbury 7647, New Zealand
- New Zealand Academy of Sport, Dunedin, New Zealand
- Department of Human Kinetics, University of British Columbia Okanagan, Kelowna, BC V6T 1Z1, Canada
| | - John Hellemans
- Department of Social Science, Parks, Recreation, Tourism, and Sport, Environment Society and Design Division, P.O. Box 84, Lincoln University, Canterbury 7647, New Zealand
- New Zealand Academy of Sport, Dunedin, New Zealand
- Department of Human Kinetics, University of British Columbia Okanagan, Kelowna, BC V6T 1Z1, Canada
| | - Philip N. Ainslie
- Department of Social Science, Parks, Recreation, Tourism, and Sport, Environment Society and Design Division, P.O. Box 84, Lincoln University, Canterbury 7647, New Zealand
- New Zealand Academy of Sport, Dunedin, New Zealand
- Department of Human Kinetics, University of British Columbia Okanagan, Kelowna, BC V6T 1Z1, Canada
| |
Collapse
|
46
|
Millet GP, Roels B, Schmitt L, Woorons X, Richalet JP. Combining hypoxic methods for peak performance. Sports Med 2010; 40:1-25. [PMID: 20020784 DOI: 10.2165/11317920-000000000-00000] [Citation(s) in RCA: 232] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
New methods and devices for pursuing performance enhancement through altitude training were developed in Scandinavia and the USA in the early 1990s. At present, several forms of hypoxic training and/or altitude exposure exist: traditional 'live high-train high' (LHTH), contemporary 'live high-train low' (LHTL), intermittent hypoxic exposure during rest (IHE) and intermittent hypoxic exposure during continuous session (IHT). Although substantial differences exist between these methods of hypoxic training and/or exposure, all have the same goal: to induce an improvement in athletic performance at sea level. They are also used for preparation for competition at altitude and/or for the acclimatization of mountaineers. The underlying mechanisms behind the effects of hypoxic training are widely debated. Although the popular view is that altitude training may lead to an increase in haematological capacity, this may not be the main, or the only, factor involved in the improvement of performance. Other central (such as ventilatory, haemodynamic or neural adaptation) or peripheral (such as muscle buffering capacity or economy) factors play an important role. LHTL was shown to be an efficient method. The optimal altitude for living high has been defined as being 2200-2500 m to provide an optimal erythropoietic effect and up to 3100 m for non-haematological parameters. The optimal duration at altitude appears to be 4 weeks for inducing accelerated erythropoiesis whereas <3 weeks (i.e. 18 days) are long enough for beneficial changes in economy, muscle buffering capacity, the hypoxic ventilatory response or Na(+)/K(+)-ATPase activity. One critical point is the daily dose of altitude. A natural altitude of 2500 m for 20-22 h/day (in fact, travelling down to the valley only for training) appears sufficient to increase erythropoiesis and improve sea-level performance. 'Longer is better' as regards haematological changes since additional benefits have been shown as hypoxic exposure increases beyond 16 h/day. The minimum daily dose for stimulating erythropoiesis seems to be 12 h/day. For non-haematological changes, the implementation of a much shorter duration of exposure seems possible. Athletes could take advantage of IHT, which seems more beneficial than IHE in performance enhancement. The intensity of hypoxic exercise might play a role on adaptations at the molecular level in skeletal muscle tissue. There is clear evidence that intense exercise at high altitude stimulates to a greater extent muscle adaptations for both aerobic and anaerobic exercises and limits the decrease in power. So although IHT induces no increase in VO(2max) due to the low 'altitude dose', improvement in athletic performance is likely to happen with high-intensity exercise (i.e. above the ventilatory threshold) due to an increase in mitochondrial efficiency and pH/lactate regulation. We propose a new combination of hypoxic method (which we suggest naming Living High-Training Low and High, interspersed; LHTLHi) combining LHTL (five nights at 3000 m and two nights at sea level) with training at sea level except for a few (2.3 per week) IHT sessions of supra-threshold training. This review also provides a rationale on how to combine the different hypoxic methods and suggests advances in both their implementation and their periodization during the yearly training programme of athletes competing in endurance, glycolytic or intermittent sports.
Collapse
Affiliation(s)
- Gregoire P Millet
- ISSUL, Institute of Sport Science, University of Lausanne, Lausanne, Switzerland.
| | | | | | | | | |
Collapse
|
47
|
High-intensity kayak performance after adaptation to intermittent hypoxia. Int J Sports Physiol Perform 2009; 1:246-60. [PMID: 19116438 DOI: 10.1123/ijspp.1.3.246] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
CONTEXT Live-high train-low altitude training produces worthwhile gains in performance for endurance athletes, but the benefits of adaptation to various forms of artificial altitude are less clear. PURPOSE To quantify the effects of intermittent hypoxic exposure on kayak performance. METHODS In a crossover design with a 6-week washout, we randomized 10 subelite male sprint kayak paddlers to hypoxia or control groups for 3 weeks (5 days/week) of intermittent hypoxic exposure using a nitrogen-filtration device. Each day's exposure consisted of alternately breathing hypoxic and ambient air for 5 minutes each over 1 hour. Performance tests were an incremental step test to estimate peak power, maximal oxygen uptake, exercise economy, and lactate threshold; a 500-m time trial; and 5 x 100-m sprints. All tests were performed on a wind-braked kayak ergometer 7 and 3 days pretreatment and 3 and 10 days posttreatment. Hemoglobin concentration was measured at 1 day pretreatment, 5 and 10 days during treatment, and 3 days after treatment. RESULTS Relative to control, at 3 days posttreatment the hypoxia group showed the following increases: peak power 6.8% (90% confidence limits, + or - 5.2%), mean repeat sprint power 8.3% (+ or - 6.7%), and hemoglobin concentration 3.6% (+ or - 3.2%). Changes in lactate threshold, mean 500-m power, maximal oxygen uptake, and exercise economy were unclear. Large effects for peak power and mean sprint speed were still present 10 days posthypoxia. CONCLUSION These effects of intermittent hypoxic exposure should enhance performance in kayak racing. The effects might be mediated via changes in oxygen transport.
Collapse
|
48
|
Lemaître F, Joulia F, Chollet D. Apnea: a new training method in sport? Med Hypotheses 2009; 74:413-5. [PMID: 19850416 DOI: 10.1016/j.mehy.2009.09.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Revised: 09/22/2009] [Accepted: 09/23/2009] [Indexed: 10/20/2022]
Abstract
The physiological responses to apnea training exhibited by elite breath-hold divers may contribute to improving sports performance. Breath-hold divers have shown reduced blood acidosis, oxidative stress and basal metabolic rate, and increased hematocrit, erythropoietin concentration, hemoglobin mass and lung volumes. We hypothesise that these adaptations contributed to long apnea durations and improve performance. These results suggest that apnea training may be an effective alternative to hypobaric or normobaric hypoxia to increase aerobic and/or anaerobic performance.
Collapse
Affiliation(s)
- Frédéric Lemaître
- Faculté des Sciences du Sport et de l'Education Physique de Rouen, Centre d'Etudes des Transformations des Activités Physiques et Sportives, Equipe d'Accueil UPRES N degrees 3832, Université de Rouen, France.
| | | | | |
Collapse
|
49
|
Hamlin MJ, Marshall HC, Hellemans J, Ainslie PN, Anglem N. Effect of intermittent hypoxic training on 20 km time trial and 30 s anaerobic performance. Scand J Med Sci Sports 2009; 20:651-61. [PMID: 19793215 DOI: 10.1111/j.1600-0838.2009.00946.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study aimed to verify whether the "live low, train high" approach is beneficial for endurance and/or anaerobic cycling performance. Sixteen well-trained athletes completed 90 min of endurance training (60-70% of heart rate reserve), followed by two 30-s all-out sprints (Wingate test), daily, for 10 consecutive days. Nine subjects [intermittent hypoxic training (IHT) group] trained with an F(I)O(2) set to produce arterial oxygen saturations of approximately 88-82%, while seven subjects (placebo group) trained while breathing a normal gas mixture (F(I)O(2)=0.21). Four performance tests were conducted at sea level including a familiarization and baseline trial, followed by repeat trials at 2 and 9 days post-intervention. Relative to the placebo group, the mean power during the 30-s Wingate test increased by 3.0% (95% confidence limits, CL +/- 3.5%) 2 days, and 1.7% (+/- 3.8%) 9 days post-IHT. Changes in other performance variables (30 s peak power, 20 km mean power and 20 km oxygen cost) were unclear. During the time trial, the IHT participants' blood lactate concentration, respiratory exchange ratio, and SpO(2), relative to the placebo group, was substantially increased at 2 days post-intervention. The addition of IHT to the normal training program of well-trained athletes produced worthwhile gains in 30 s sprint performance possibly through enhanced glycolysis.
Collapse
Affiliation(s)
- M J Hamlin
- Social Sciences Tourism & Recreation Group, Environment, Society and Design Division, Lincoln University, Canterbury, New Zealand.
| | | | | | | | | |
Collapse
|
50
|
Cycling Performance Following Adaptation to Two Protocols of Acutely Intermittent Hypoxia. Int J Sports Physiol Perform 2009; 4:68-83. [DOI: 10.1123/ijspp.4.1.68] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Purpose:Adaptation to acutely intermittent hypoxic exposure appears to produce worthwhile enhancements in endurance performance, but the current 5-min duration of hypoxia and recovery intervals may not be optimal.Methods:Eighteen male competitive cyclists and triathletes were randomized to one of two intermittent-hypoxia groups, and nine similar athletes represented a control group. Athletes in the hypoxia groups were exposed to 60 min per day of intermittent hypoxia consisting of alternating intervals of hypoxia and normoxia lasting either 3 or 5 min. Exposures were performed at rest for 5 consecutive days per week for 3 wk. Oxygen saturation, monitored with pulse oximetry, was reduced progressively from 90% (day 1) to 76% (day 15). All athletes maintained their usual competitive-season training throughout the study. Incremental and repeated-sprint tests were performed pre, 3 d post, and 14 d post intervention. Venous blood at rest was sampled pre, mid-, and postintervention.Results:There were no clear differences between effects of the two hypoxic treatments on performance or various measures of oxygen transport, hematopoiesis, and inflammation. Compared with control, the combined hypoxic groups showed clear enhancements in peak power (4.7%; 90% confidence limits, ±3.1%), lactate-profile power (4.4%; ±3.0%), and heart-rate profle power (6.5%; ±5.3%) at 3 d post intervention, but at 14 d the effects were unclear. Changes in other measures at 3 and 14 d post intervention were either unclear or unremarkable.Conclusion:Acutely intermittent hypoxia produced substantial enhancement in endurance performance, but the relative benefit of 3- vs 5-min exposure intervals remains unclear.
Collapse
|