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Feng X, Chen Y, Yan T, Lu H, Wang C, Zhao L. Effects of various living-low and training-high modes with distinct training prescriptions on sea-level performance: A network meta-analysis. PLoS One 2024; 19:e0297007. [PMID: 38635743 PMCID: PMC11025749 DOI: 10.1371/journal.pone.0297007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 12/22/2023] [Indexed: 04/20/2024] Open
Abstract
This study aimed to separately compare and rank the effect of various living-low and training-high (LLTH) modes on aerobic and anaerobic performances in athletes, focusing on training intensity, modality, and volume, through network meta-analysis. We systematically searched PubMed, Web of Science, Embase, EBSCO, and Cochrane from their inception date to June 30, 2023. Based on the hypoxic training modality and the intensity and duration of work intervals, LLTH was divided into intermittent hypoxic exposure, continuous hypoxic training, repeated sprint training in hypoxia (RSH; work interval: 5-10 s and rest interval: approximately 30 s), interval sprint training in hypoxia (ISH; work interval: 15-30 s), short-duration high-intensity interval training (s-IHT; short work interval: 1-2 min), long-duration high-intensity interval training (l-IHT; long work interval: > 5 min), and continuous and interval training under hypoxia. A meta-analysis was conducted to determine the standardized mean differences (SMDs) among the effects of various hypoxic interventions on aerobic and anaerobic performances. From 2,072 originally identified titles, 56 studies were included in the analysis. The pooled data from 53 studies showed that only l-IHT (SMDs: 0.78 [95% credible interval; CrI, 0.52-1.05]) and RSH (SMDs: 0.30 [95% CrI, 0.10-0.50]) compared with normoxic training effectively improved athletes' aerobic performance. Furthermore, the pooled data from 29 studies revealed that active intermittent hypoxic training compared with normoxic training can effectively improve anaerobic performance, with SMDs ranging from 0.97 (95% CrI, 0.12-1.81) for l-IHT to 0.32 (95% CrI, 0.05-0.59) for RSH. When adopting a program for LLTH, sufficient duration and work intensity intervals are key to achieving optimal improvements in athletes' overall performance, regardless of the potential improvement in aerobic or anaerobic performance. Nevertheless, it is essential to acknowledge that this study incorporated merely one study on the improvement of anaerobic performance by l-IHT, undermining the credibility of the results. Accordingly, more related studies are needed in the future to provide evidence-based support. It seems difficult to achieve beneficial adaptive changes in performance with intermittent passive hypoxic exposure and continuous low-intensity hypoxic training.
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Affiliation(s)
- Xinmiao Feng
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Yonghui Chen
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Teishuai Yan
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Hongyuan Lu
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Chuangang Wang
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Linin Zhao
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
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2
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Hohenauer E, Bianchi G, Wellauer V, Taube W, Clijsen R. Acute physiological responses and muscle recovery in females: a randomised controlled trial of muscle damaging exercise in hypoxia. BMC Sports Sci Med Rehabil 2024; 16:70. [PMID: 38520001 PMCID: PMC10960417 DOI: 10.1186/s13102-024-00861-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 03/11/2024] [Indexed: 03/25/2024]
Abstract
BACKGROUND Studies have investigated the effects of training under hypoxia (HYP) after several weeks in a male population. However, there is still a lack of knowledge on the acute hypoxic effects on physiology and muscle recovery in a female population. METHODS This randomized-controlled trial aimed to investigate the acute effects of muscle damaging exercise, performed in HYP and normoxia (CON), on physiological responses and recovery characteristics in healthy females. Key inclusion criteria were recreationally active female participants between the age of 18 to 35 years without any previous surgeries and injuries, whilst key exclusion criteria were acute pain situations, pregnancy, and medication intake. The females conducted a muscle-damaging protocol, comprising 5 × 20 drop-jumps, in either HYP (FiO2: 12%) or CON (FiO2: 21%). Physiological responses, including capillary oxygenation (SpO2), muscle oxygenation (SmO2), heart rate (HR), core- (Tcore) and skin- (Tskin) temperature were assessed at the end of each exercise set. Recovery characteristics were quantified by taking venous blood samples (serum creatine-kinase [CK], C-reactive protein [CRP] and blood sedimentation rate [BSR]), assessing muscle swelling of the quadriceps femoris muscle, maximum voluntary isometric contraction (MVIC) of the knee extensor muscles, countermovement jump (CMJ) performance and muscle soreness ratings (DOMS) at 24-, 48- and 72-hrs post-exercise. RESULTS SpO2 (HYP: 76.7 ± 3.8%, CON: 95.5 ± 1.7%, p < 0.001) and SmO2 (HYP: 60.0 ± 9.3, CON: 73.4 ± 5.8%, p = 0.03) values were lower (p < 0.05) in HYP compared to CON at the end of the exercise-protocol. No physiological differences between HYP and CON were observed for HR, Tcore, and Tskin (all p > 0.05). There were also no differences detected for any recovery variable (CK, CRP, BSR, MVIC, CMJ, and DOMS) during the 72-hrs follow-up period between HYP and CON (all p > 0.05). CONCLUSION In conclusion, our results showed that muscle damaging exercise under HYP leads to reduced capillary and muscle oxygenation levels compared to normoxia with no difference in inflammatory response and muscle recovery during 72 h post-exercise. TRIAL REGISTRATION NCT04902924, May 26th 2021.
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Affiliation(s)
- Erich Hohenauer
- RESlab, University of Applied Sciences and Arts of Southern Switzerland, Weststrasse 8, CH-7302, Landquart, Switzerland.
- International University of Applied Sciences THIM, Landquart, Switzerland.
- University of Fribourg, Fribourg, Switzerland.
| | - G Bianchi
- RESlab, University of Applied Sciences and Arts of Southern Switzerland, Weststrasse 8, CH-7302, Landquart, Switzerland
| | - V Wellauer
- RESlab, University of Applied Sciences and Arts of Southern Switzerland, Weststrasse 8, CH-7302, Landquart, Switzerland
| | - W Taube
- University of Fribourg, Fribourg, Switzerland
| | - R Clijsen
- RESlab, University of Applied Sciences and Arts of Southern Switzerland, Weststrasse 8, CH-7302, Landquart, Switzerland
- International University of Applied Sciences THIM, Landquart, Switzerland
- Department of Movement and Sport Sciences, Vrije Universiteit Brussel, Brussels, Belgium
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Jones N, Oke J, Marsh S, Nikbin K, Bowley J, Dijkstra HP, Hobbs FR, Greenhalgh T. Face masks while exercising trial (MERIT): a cross-over randomised controlled study. BMJ Open 2023; 13:e063014. [PMID: 36604128 PMCID: PMC9827243 DOI: 10.1136/bmjopen-2022-063014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 12/01/2022] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVES Physical exertion is a high-risk activity for aerosol emission of respiratory pathogens. We aimed to determine the safety and tolerability of healthy young adults wearing different types of face mask during moderate-to-high intensity exercise. DESIGN Cross-over randomised controlled study, completed between June 2021 and January 2022. PARTICIPANTS Volunteers aged 18-35 years, who exercised regularly and had no significant pre-existing health conditions. INTERVENTIONS Comparison of wearing a surgical, cloth and filtering face piece (FFP3) mask to no mask during 4×15 min bouts of exercise. Exercise was running outdoors or indoor rowing at moderate-to-high intensity, with consistency of distance travelled between bouts confirmed using a smartphone application (Strava). Each participant completed each bout in random order. OUTCOMES The primary outcome was change in oxygen saturations. Secondary outcomes were change in heart rate, perceived impact of face mask wearing during exercise and willingness to wear a face mask for future exercise. RESULTS All 72 volunteers (mean age 23.9) completed the study. Changes in oxygen saturations did not exceed the prespecified non-inferiority margin (2% difference) with any mask type compared with no mask. At the end of exercise, the estimated average difference in oxygen saturations for cloth mask was -0.07% (95% CI -0.39% to 0.25%), for surgical 0.28% (-0.04% to 0.60%) and for FFP3 -0.21% (-0.53% to 0.11%). The corresponding estimated average difference in heart rate for cloth mask was -1.20 bpm (95% CI -4.56 to 2.15), for surgical 0.36 bpm (95% CI -3.01 to 3.73) and for FFP3 0.52 bpm (95% CI -2.85 to 3.89). Wearing a face mask caused additional symptoms such as breathlessness (n=13, 18%) and dizziness (n=7, 10%). 33 participants broadly supported face mask wearing during exercise, particularly indoors, but 22 were opposed. CONCLUSION This study adds to previous findings (mostly from non-randomised studies) that exercising at moderate-to-high intensity wearing a face mask appears to be safe in healthy, young adults. TRIAL REGISTRATION NUMBER NCT04932226.
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Affiliation(s)
- Nicholas Jones
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Jason Oke
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Seren Marsh
- University of Oxford Medical School, University of Oxford, Oxford, UK
| | - Kurosh Nikbin
- GKT School of Medical Education, King's College London, London, UK
| | - Jonathan Bowley
- School of Medicine, University of Nottingham, Nottingham, UK
| | - H Paul Dijkstra
- Department of Continuing Education, University of Oxford, Oxford, UK
- Medical Education Department, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
| | - Fd Richard Hobbs
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Trisha Greenhalgh
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
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Suzuki J. Endurance exercise under short-duration intermittent hypoxia promotes endurance performance via improving muscle metabolic properties in mice. Physiol Rep 2022; 10:e15534. [PMID: 36514879 PMCID: PMC9748492 DOI: 10.14814/phy2.15534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 10/13/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023] Open
Abstract
This study was designed to (1) investigate the effects of acute exercise under intermittent hypoxia on muscle mRNA and protein levels, and (2) clarify the mechanisms by which exercise under intermittent hypoxia improves endurance capacity. Experiment-1: Male mice were subjected to either acute endurance exercise, exercise under hypoxia (14% O2 ), exercise under intermittent hypoxia (Int, three cycles of room air [10 min] and 14% O2 [15 min]). At 3 h after exercise under intermittent hypoxia, sirtuin-6 mRNA levels and nuclear prolyl hydroxylases-2 protein levels were significantly upregulated in white gastrocnemius muscle in the Int group. Experiment-2: Mice were assigned to sedentary control (Sed), normoxic exercise-trained (ET), hypoxic exercise-trained (HYP) or exercise-trained under intermittent hypoxia (INT) groups. Exercise capacity was significantly greater in the INT group than in the ET and HYP group. Activity levels of citrate synthase were significantly greater in the INT group than in the HYP group in soleus (SOL) and red gastrocnemius muscles. In SOL, nuclear N-terminal PGC1α levels were considerably increased by the INT training (95% confidence interval [CI]: 1.09-1.79). The INT significantly increased pyruvate dehydrogenase complex activity levels in left ventricle (LV). Monocarboxylate transporter-4 protein levels were significantly increased after the INT training in LV. Capillary-to-fiber ratio values were significantly increased in SOL and were substantially increased in LV (CI: 1.10-1.22) after the INT training. These results suggest that exercise training under intermittent hypoxia represents a beneficial strategy for increasing endurance performance via improving metabolic properties and capillary profiles in several hind-leg muscles and the heart.
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Affiliation(s)
- Junichi Suzuki
- Laboratory of Exercise Physiology, Health and Sports Sciences, Course of Sports Education, Department of EducationHokkaido University of EducationIwamizawaJapan
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Gasser B. Deathly Accidents While High-Altitude Mountaineering in the Swiss Alps-An Observational Analysis from 2009 to 2021. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:12498. [PMID: 36231795 PMCID: PMC9566316 DOI: 10.3390/ijerph191912498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/22/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND High-altitude mountaineering has become more and more popular. While many enjoy the beauty of the highest parts of Switzerland, there are considerable risks, which can even result in death. This study analyzed fatal events while high-altitude mountaineering in the Swiss Alps. MATERIALS AND METHODS In this study, cases of emergencies while high-altitude mountaineering in the Swiss Alps were analyzed in the period from 2009 to 2021 from the Swiss Alpine Club (SAC) emergency registry. Fatal emergencies were identified and analyzed in detail. RESULTS In total, 5020 emergency cases were analyzed, and among them 303 deathly events where detected. Of the fatal emergencies, 261 cases (86.1%) were male and 42 (13.9%) were female. The average age was 53.2 ± 19.1 years. More than half of the emergencies were on a route to a classic four-thousander. Fatal events were most common on the Matterhorn, with 40 cases (13.2%); on the Mönch, with 18 cases (5.9%); and on the Piz Bernina, with 10 cases (3.3%). In 245 of the fatal emergencies (80.9%), a fall was the cause. The second most prominent cause was rockfalls, with 16 cases (5.3%), followed by stranding, with 10 cases (3.3%), and avalanches, with 9 cases (3%). Illnesses and crevasse accidents counted together for less than 5% of the fatal cases. Almost two-thirds of fatal falls occurred while descending. Concerning nationality, 30% were from Switzerland and more than three-fourths of victims were from the countries of the Alps. DISCUSSION We found that falls were the most common cause of fatal emergencies in the Swiss Alps. Concerning the fact that most of these emergencies occurred during descents, fatigue and inadequate focus (forgetting the risks of the descent after successfully reaching the peak) are potential reasons for the fatal events. This potentially resulted from a lack of acclimatization, insufficient physical fitness, and inadequate tour planning. Since most victims were from the countries of the Alps, training tours may be possible as a recommended preparation for more difficult four-thousander peaks.
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Affiliation(s)
- Benedikt Gasser
- Departement für Sport, Bewegung und Gesundheit-Abteilung Rehabilitative und Regenerative Sportmedizin-Universität Basel-Grosse Allee 6, CH-4052 Basel, Switzerland
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Fernández-Lázaro D, Mielgo-Ayuso J, Santamaría G, Gutiérrez-Abejón E, Domínguez-Ortega C, García-Lázaro SM, Seco-Calvo J. Adequacy of an Altitude Fitness Program (Living and Training) plus Intermittent Exposure to Hypoxia for Improving Hematological Biomarkers and Sports Performance of Elite Athletes: A Single-Blind Randomized Clinical Trial. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:9095. [PMID: 35897470 PMCID: PMC9368232 DOI: 10.3390/ijerph19159095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/23/2022] [Accepted: 07/25/2022] [Indexed: 11/17/2022]
Abstract
Athletes incorporate altitude training programs into their conventional training to improve their performance. The purpose of this study was to determine the effects of an 8-week altitude training program that was supplemented with intermittent hypoxic training (IHE) on the blood biomarkers, sports performance, and safety profiles of elite athletes. In a single-blind randomized clinical trial that followed the CONSORT recommendations, 24 male athletes were randomized to an IHE group (HA, n = 12) or an intermittent normoxia group (NA, n = 12). The IHE consisted of 5-min cycles of hypoxia−normoxia with an FIO2 of between 10−13% for 90 min every day for 8 weeks. Hematological (red blood cells, hemoglobin, hematocrit, hematocrit, reticulated hemoglobin, reticulocytes, and erythropoietin), immunological (leukocytes, monocytes, and lymphocytes), and renal (urea, creatinine, glomerular filtrate, and total protein) biomarkers were assessed at the baseline (T1), day 28 (T2), and day 56 (T3). Sports performance was evaluated at T1 and T3 by measuring quadriceps strength and using three-time trials over the distances of 60, 400, and 1000 m on an athletics track. Statistically significant increases (p < 0.05) in erythropoietin, reticulocytes, hemoglobin, and reticulocyte hemoglobin were observed in the HA group at T3 with respect to T1 and the NA group. In addition, statistically significant improvements (p < 0.05) were achieved in all performance tests. No variations were observed in the immunological or renal biomarkers. The athletes who were living and training at 1065 m and were supplemented with IHE produced significant improvements in their hematological behavior and sports performance with optimal safety profiles.
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Affiliation(s)
- Diego Fernández-Lázaro
- Department of Cellular Biology, Genetics, Histology and Pharmacology, Faculty of Health Sciences, Campus of Soria, University of Valladolid, 42003 Soria, Spain; (G.S.); (C.D.-O.)
- Neurobiology Research Group, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain
| | - Juan Mielgo-Ayuso
- Department of Health Sciences, Faculty of Health Sciences, University of Burgos, 09001 Burgos, Spain
| | - Gema Santamaría
- Department of Cellular Biology, Genetics, Histology and Pharmacology, Faculty of Health Sciences, Campus of Soria, University of Valladolid, 42003 Soria, Spain; (G.S.); (C.D.-O.)
| | - Eduardo Gutiérrez-Abejón
- Pharmacological Big Data Laboratory, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain;
- Pharmacy Directorate, Castilla y León Health Council, 47007 Valladolid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (Group CB21/13/00051), Carlos III Institute of Health, 28029 Madrid, Spain
| | - Carlos Domínguez-Ortega
- Department of Cellular Biology, Genetics, Histology and Pharmacology, Faculty of Health Sciences, Campus of Soria, University of Valladolid, 42003 Soria, Spain; (G.S.); (C.D.-O.)
- Hematology Service of Santa Bárbara Hospital, Castile and Leon Health Network (SACyL), 42003 Soria, Spain
| | - Sandra María García-Lázaro
- Department of Surgery, Ophthalmology, Otorhinolaryngology, and Physiotherapy, Faculty of Health Sciences, Campus of Soria, University of Valladolid, 42003 Soria, Spain;
| | - Jesús Seco-Calvo
- Physiotherapy Department, Institute of Biomedicine (IBIOMED), Campus of Vegazana, University of Leon, 24071 Leon, Spain;
- Psychology Department, Faculty of Medicine, Basque Country University, 48900 Leioa, Spain
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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: 3] [Impact Index Per Article: 1.5] [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.
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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.)
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Malgoyre A, Prola A, Meunier A, Chapot R, Serrurier B, Koulmann N, Bigard X, Sanchez H. Endurance Is Improved in Female Rats After Living High-Training High Despite Alterations in Skeletal Muscle. Front Sports Act Living 2021; 3:663857. [PMID: 34124658 PMCID: PMC8193088 DOI: 10.3389/fspor.2021.663857] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 04/12/2021] [Indexed: 11/29/2022] Open
Abstract
Altitude camps are used during the preparation of endurance athletes to improve performance based on the stimulation of erythropoiesis by living at high altitude. In addition to such whole-body adaptations, studies have suggested that high-altitude training increases mitochondrial mass, but this has been challenged by later studies. Here, we hypothesized that living and training at high altitude (LHTH) improves mitochondrial efficiency and/or substrate utilization. Female rats were exposed and trained in hypoxia (simulated 3,200 m) for 5 weeks (LHTH) and compared to sedentary rats living in hypoxia (LH) or normoxia (LL) or those that trained in normoxia (LLTL). Maximal aerobic velocity (MAV) improved with training, independently of hypoxia, whereas the time to exhaustion, performed at 65% of MAV, increased both with training (P = 0.009) and hypoxia (P = 0.015), with an additive effect of the two conditions. The distance run was 7.98 ± 0.57 km in LHTH vs. 6.94 ± 0.51 in LLTL (+15%, ns). The hematocrit increased >20% with hypoxia (P < 0.001). The increases in mitochondrial mass and maximal oxidative capacity with endurance training were blunted by combination with hypoxia (−30% for citrate synthase, P < 0.01, and −23% for Vmax glut−succ, P < 0.001 between LHTH and LLTL). A similar reduction between the LHTH and LLTL groups was found for maximal respiration with pyruvate (−29%, P < 0.001), for acceptor-control ratio (−36%, hypoxia effect, P < 0.001), and for creatine kinase efficiency (−48%, P < 0.01). 3-hydroxyl acyl coenzyme A dehydrogenase was not altered by hypoxia, whereas maximal respiration with Palmitoyl-CoA specifically decreased. Overall, our results show that mitochondrial adaptations are not involved in the improvement of submaximal aerobic performance after LHTH, suggesting that the benefits of altitude camps in females relies essentially on other factors, such as the transitory elevation of hematocrit, and should be planned a few weeks before competition and not several months.
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Affiliation(s)
- Alexandra Malgoyre
- Département des Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France.,Laboratoire de Biologie de l'Exercice pour la Performance et la Santé, Université Evry, Université Paris Saclay, Evry, France
| | - Alexandre Prola
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Adelie Meunier
- Département des Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France
| | - Rachel Chapot
- Département des Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France
| | - Bernard Serrurier
- Département des Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France
| | - Nathalie Koulmann
- Département des Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France.,Laboratoire de Biologie de l'Exercice pour la Performance et la Santé, Université Evry, Université Paris Saclay, Evry, France.,Ecole du Val de Grâce, Paris, France
| | - Xavier Bigard
- Département des Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France.,Ecole du Val de Grâce, Paris, France
| | - Hervé Sanchez
- Département des Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France
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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.
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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
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Verratti V, Bondi D, Mulliri G, Ghiani G, Crisafulli A, Pietrangelo T, Marinozzi ME, Cerretelli P. Muscle Oxygen Delivery in the Forearm and in the Vastus Lateralis Muscles in Response to Resistance Exercise: A Comparison Between Nepalese Porters and Italian Trekkers. Front Physiol 2020; 11:607616. [PMID: 33240112 PMCID: PMC7683416 DOI: 10.3389/fphys.2020.607616] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 10/19/2020] [Indexed: 12/25/2022] Open
Abstract
Altitude ascending represents an intriguing experimental model reproducing physiological and pathophysiological conditions sharing hypoxemia as the denominator. The aim of the present study was to investigate fractional oxygen extraction and blood dynamics in response to hypobaric hypoxia and to acute resistance exercises, taking into account several factors including different ethnic origin and muscle groups. As part of the “Kanchenjunga Exploration & Physiology” project, six Italian trekkers and six Nepalese porters took part in a high altitude trek in the Himalayas. The measurements were carried out at low (1,450 m) and high altitude (HA; 4,780 m). Near-infrared spectroscopy (NIRS)-derived parameters, i.e., Tot-Hb and tissue saturation index (TSI), were gathered at rest and after bouts of 3-min resistive exercise, both in the quadriceps and in the forearm muscles. TSI decreased with altitude, particularly in forearm muscles (from 66.9 to 57.3%), whereas the decrement was less in the quadriceps (from 62.5 to 57.2%); Nepalese porters were characterized by greater values in thigh TSI than Italian trekkers. Tot-Hb was increased after exercise. At altitude, such increase appeared to be higher in the quadriceps. This effect might be a consequence of the long-term adaptive memory due to the frequent exposures to altitude. Although speculative, we suggest a long-term adaptation of the Nepalese porters due to improved oxygenation of muscles frequently undergoing hypoxic exercise. Muscle structure, individual factors, and altitude exposure time should be taken into account to move on the knowledge of oxygen delivery and utilization at altitude.
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Affiliation(s)
- Vittore Verratti
- Department of Psychological, Health and Territorial Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Danilo Bondi
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Gabriele Mulliri
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Giovanna Ghiani
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Antonio Crisafulli
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Tiziana Pietrangelo
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | | | - Paolo Cerretelli
- Institute of Bioimaging and Molecular Physiology, National Research Council of Italy, Segrate, Italy
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11
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No Influence of Acute Moderate Normobaric Hypoxia on Performance and Blood Lactate Concentration Responses to Repeated Wingates. Int J Sports Physiol Perform 2020; 16:154-157. [PMID: 33120358 DOI: 10.1123/ijspp.2019-0933] [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] [Received: 11/19/2019] [Revised: 02/26/2020] [Accepted: 03/02/2020] [Indexed: 11/18/2022]
Abstract
BACKGROUND Training in hypoxia versus normoxia often induces larger physiological adaptations, while this does not always translate into additional performance benefits. A possible explanation is a reduced oxygen flux, negatively affecting training intensity and/or volume (decreasing training stimulus). Repeated Wingates (RW) in normoxia is an efficient training strategy for improving both physiological parameters and exercise capacity. However, it remains unclear whether the addition of hypoxia has a detrimental effect on RW performance. PURPOSE To test the hypothesis that acute moderate hypoxia exposure has no detrimental effect on RW, while both metabolic and perceptual responses would be slightly higher. METHODS On separate days, 7 male university sprinters performed 3 × 30-s Wingate efforts with 4.5-min passive recovery in either hypoxia (FiO2: 0.145) or normoxia (FiO2: 0.209). Arterial oxygen saturation was assessed before the first Wingate effort, while blood lactate concentration and ratings of perceived exertion were measured after each bout. RESULTS Mean (P = .92) and peak (P = .63) power outputs, total work (P = .98), and the percentage decrement score (P = .25) were similar between conditions. Arterial oxygen saturation was significantly lower in hypoxia versus normoxia (92.0% [2.8%] vs 98.1% [0.4%], P < .01), whereas blood lactate concentration (P = .78) and ratings of perceived exertion (P = .51) did not differ between conditions. CONCLUSION In sprinters, acute exposure to moderate hypoxia had no detrimental effect on RW performance and associated metabolic and perceptual responses.
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12
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Intermittent Hypoxic Exposure Reduces Endothelial Dysfunction. BIOMED RESEARCH INTERNATIONAL 2020; 2020:6479630. [PMID: 32923484 PMCID: PMC7453230 DOI: 10.1155/2020/6479630] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/11/2020] [Accepted: 07/09/2020] [Indexed: 12/14/2022]
Abstract
Intermittent exposure to hypoxia (IHE) increases the production of reactive oxygen and nitrogen species as well as erythropoietin (EPO), which stimulates the adaptation to intense physical activity. However, several studies suggest a protective effect of moderate hypoxia in cardiovascular disease (CVD) events. The effects of intense physical activity with IHE on oxi-inflammatory mediators and their interaction with conventional CVD risk factors were investigated. Blood samples were collected from elite athletes (control n = 6, IHE n = 6) during a 6-day IHE cycle using hypoxicator GO2 altitude. IHE was held once a day, at least 2 hours after training. In serum, hydrogen peroxide (H2O2), nitric oxide (NO), 3-nitrotyrosine (3-Nitro), proinflammatory cytokines (IL-1β and TNFα), high sensitivity C-reactive protein (hsCRP), and heat shock protein 27 (HSP27) were determined by the commercial immunoenzyme (ELISA kits) or colorimetric methods. Serum erythropoietin (EPO) level was measured by ELISA kit every day of hypoxia. IHE was found to significantly increase H2O2, NO, and HSP27 but to decrease 3NT concentrations. The changes in 3NT and HSP27 following hypoxia proved to enhance NO bioavailability and endothelial function. In the present study, the oxi-inflammatory mediators IL-1β and hsCRP increased in IHE group but they did not exceed the reference values. The serum EPO level increased on the 3rd day of IHE, then decreased on 5th day of IHE, and correlated with NO/H2O2 ratio (r s = 0.640, P < 0.05). There were no changes in haematological markers contrary to lipoproteins such as low-density lipoprotein (LDL) and non-high-density lipoprotein (non-HDL) which showed a decreasing trend in response to hypoxic exposure. The study demonstrated that IHE combined with sports activity reduced a risk of endothelial dysfunction and atherogenesis in athletes even though the oxi-inflammatory processes were enhanced. Therefore, 6-day IHE seems to be a potential therapeutic and nonpharmacological method to reduce CVD risk, especially in elite athletes participating in strenuous training.
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13
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Intermittent Hypoxic Exposure with High Dose of Arginine Impact on Circulating Mediators of Tissue Regeneration. Nutrients 2020; 12:nu12071933. [PMID: 32610647 PMCID: PMC7400083 DOI: 10.3390/nu12071933] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 12/16/2022] Open
Abstract
Intermittent exposure to hypoxia (IHE) increases production of reactive oxygen and nitrogen species which, as signalling molecules, participate in tissue injury–repair–regeneration cascade. The process is also stimulated by arginine whose bioavailability is a limiting factor for NO synthesis. The effects of IHE in combination with arginine (Arg) intake on myogenesis and angiogenesis mediators were examined in a randomized and placebo-controlled trial. Blood samples were collected from 38 elite athletes on the 1st, 7th and 14th days during the training camp. The oral doses of arginine (2 × 6 g/day) and/or IHE using hypoxicator GO2Altitude (IHE and Arg/IHE) were applied. Serum NO and H2O2 concentrations increased significantly and were related to muscle damage (CK activity >900 IU/mL) in IHE and Arg/IHE compared to placebo. The changes in NO and H2O2 elevated the levels of circulating growth factors such as HGF, IHG-1, PDGFBB, BDNF, VEGF and EPO. Modification of the lipid profile, especially reduced non-HDL, was an additional beneficial effect of hypoxic exposure with arginine intake. Intermittent hypoxic exposure combined with high-dose arginine intake was demonstrated to affect circulating mediators of injury–repair–regeneration. Therefore, a combination of IHE and arginine seems to be a potential therapeutic and non-pharmacological method to modulate the myogenesis and angiogenesis in elite athletes.
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14
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Nascimento GC, Malzone BL, Iyomasa DM, Pereira YCL, Issa JPM, Leite-Panissi CRA, Watanabe IS, Iyomasa MM, Fuentes R, Del Bel E, Dias FJ. Beneficial effects of benzodiazepine on masticatory muscle dysfunction induced by chronic stress and occlusal instability in an experimental animal study. Sci Rep 2020; 10:8787. [PMID: 32472004 PMCID: PMC7260241 DOI: 10.1038/s41598-020-65524-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 04/07/2020] [Indexed: 11/09/2022] Open
Abstract
Psychological stress and occlusal alteration are important etiologic factors for temporomandibular/masticatory muscular disorders. In particular, the exact physiologic mechanism underlying the relation by occlusal alteration and temporomandibular disorders remains unclear. Our purpose was to test the hypothesis that benzodiazepine therapy is able to prevent metabolic and vascular changes in the medial pterygoid muscle of rats under chronic stress after 14 days of unilateral exodontia. Adult Wistar rats were submitted to unpredictable chronic mild stress (10 days) and/or unilateral exodontia and their plasma and medial pterygoid muscles were removed for analysis. A pre-treatment with diazepam was used to verify its effect on stress. The parameters evaluated included anxiety behavior, plasma levels of corticosterone, metabolic activity by succinate dehydrogenase, capillary density by laminin staining and ultrastructural findings by transmission electron microscopy. Occlusal instability induced anxiety-like behavior on elevated plus-maze test and diazepam administration blocked the appearance of this behavior. Unilateral exodontia promoted in the contralateral muscle an increase of oxidative fibers and capillaries and modification of sarcoplasmic reticulum. Chronic stress caused increased glycolytic metabolism, reduced capillary density and morphological changes in mitochondria on both sides. Association of both factors induced a glycolytic pattern in muscle and hemodynamic changes. Pharmacological manipulation with diazepam inhibited the changes in the medial pterygoid muscle after stress. Our results reveal a preventive benzodiazepine treatment for stress and occlusal instability conditions affecting masticatory muscle disorders. In addition, provide insights into the mechanisms by which chronic stress and exodontia might be involved in the pathophysiology of masticatory muscular dysfunctions.
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Affiliation(s)
- Glauce C Nascimento
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Bruno L Malzone
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Daniela M Iyomasa
- Department of Morphology, Presidente Prudente Medical School, Universidade do Oeste Paulista, Presidente Prudente, SP, Brazil
| | - Yamba C L Pereira
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - João Paulo M Issa
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Christie R A Leite-Panissi
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Ii-Sei Watanabe
- Department of Anatomy, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Mamie M Iyomasa
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Ramon Fuentes
- Department of Integral Dentistry, Research Centre for Dental Sciences (CICO), Dental School, Universidad de La Frontera, Temuco, Chile
| | - Elaine Del Bel
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
| | - Fernando J Dias
- Department of Integral Dentistry, Research Centre for Dental Sciences (CICO), Dental School, Universidad de La Frontera, Temuco, Chile.
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15
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Mukai K, Ohmura H, Matsui A, Aida H, Takahashi T, Jones JH. High-intensity training in normobaric hypoxia enhances exercise performance and aerobic capacity in Thoroughbred horses: A randomized crossover study. Physiol Rep 2020; 8:e14442. [PMID: 32441408 PMCID: PMC7243200 DOI: 10.14814/phy2.14442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/09/2020] [Accepted: 04/19/2020] [Indexed: 01/28/2023] Open
Abstract
We examined the effects of high-intensity training in normobaric hypoxia on aerobic capacity and exercise performance in horses and the individual response to normoxic and hypoxic training. Eight untrained horses were studied in a randomized, crossover design after training in hypoxia (HYP; 15.0% inspired O2 ) or normoxia (NOR; 20.9% inspired O2 ) 3 days/week for 4 weeks separated by a 4-month washout period. Before and after each training period, incremental treadmill exercise tests were performed in normoxia. Each training session consisted of 1 min cantering at 7 m/s and 2 min galloping at the speed determined to elicit maximal oxygen consumption ( V ˙ O2 max) in normoxia. Hypoxia increased significantly more than NOR in run time to exhaustion (HYP, +28.4%; NOR, +10.4%, p = .001), V ˙ O2 max (HYP, +12.1%; NOR, +2.6%, p = .042), cardiac output ( Q ˙ ; HYP, +11.3%; NOR, -1.7%, p = .019), and stroke volume (SV) at exhaustion (HYP, +5.4%; NOR, -5.5%, p = .035) after training. No significant correlations were observed between NOR and HYP for individual changes after training in run time (p = .21), V ˙ O2 max (p = .99), Q ˙ (p = .19), and SV (p = .46) at exhaustion. Arterial O2 saturation during exercise in HYP was positively correlated with the changes in run time (r = .85, p = .0073), Q ˙ (r = .72, p = .043) and SV (r = .77, p = .026) of HYP after training, whereas there were no correlations between these parameters in NOR. These results suggest that high-intensity training in normobaric hypoxia improved exercise performance and aerobic capacity of horses to a greater extent than the same training protocol in normoxia, and the severity of hypoxemia during hypoxic exercise might be too stressful for poor responders to hypoxic training.
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Affiliation(s)
- Kazutaka Mukai
- Sports Science DivisionEquine Research InstituteJapan Racing AssociationUtsunomiyaTochigiJapan
- Present address:
Sports Science DivisionEquine Research InstituteJapan Racing AssociationShimotsukeTochigiJapan
| | - Hajime Ohmura
- Sports Science DivisionEquine Research InstituteJapan Racing AssociationUtsunomiyaTochigiJapan
- Present address:
Sports Science DivisionEquine Research InstituteJapan Racing AssociationShimotsukeTochigiJapan
| | - Akira Matsui
- Sports Science DivisionEquine Research InstituteJapan Racing AssociationUtsunomiyaTochigiJapan
- Present address:
Equine Science DivisionHidaka Training and Research CenterJapan Racing AssociationUrakawaHokkaidoJapan
| | - Hiroko Aida
- Sports Science DivisionEquine Research InstituteJapan Racing AssociationUtsunomiyaTochigiJapan
- Present address:
Equestrian AffairsJapan Racing AssociationTokyoJapan
| | - Toshiyuki Takahashi
- Sports Science DivisionEquine Research InstituteJapan Racing AssociationUtsunomiyaTochigiJapan
- Present address:
Sports Science DivisionEquine Research InstituteJapan Racing AssociationShimotsukeTochigiJapan
| | - James H. Jones
- Department of Surgical and Radiological SciencesSchool of Veterinary MedicineUniversity of CaliforniaDavisCAUSA
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16
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Takei N, Kakinoki K, Girard O, Hatta H. Short-Term Repeated Wingate Training in Hypoxia and Normoxia in Sprinters. Front Sports Act Living 2020; 2:43. [PMID: 33345035 PMCID: PMC7739589 DOI: 10.3389/fspor.2020.00043] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/31/2020] [Indexed: 12/22/2022] Open
Abstract
Repeated Wingate efforts (RW) represent an effective training strategy for improving exercise capacity. Living low-training high altitude/hypoxic training methods, that upregulate muscle adaptations, are increasingly popular. However, the benefits of RW training in hypoxia compared to normoxia on performance and accompanying physiological adaptations remain largely undetermined. Our intention was to test the hypothesis that RW training in hypoxia provides additional performance benefits and more favorable physiological responses than equivalent training in normoxia. Twelve male runners (university sprinters) completed six RW training sessions (3 × 30-s Wingate “all-out” efforts with 4.5-min recovery) in either hypoxia (FiO2: 0.145, n = 6) or normoxia (FiO2: 0.209, n = 6) over 2 weeks. Before and after the intervention, participants underwent a RW performance test (3 × 30-s Wingate “all-out” efforts with 4.5-min recovery). Peak power output, mean power output, and total work for the three exercise bouts were determined. A capillary blood sample was taken for analyzing blood lactate concentration (BLa) 3 min after each of the three efforts. Peak power output (+ 11.3 ± 23.0%, p = 0.001), mean power output (+ 6.6 ± 6.8%, p = 0.001), and total work (+ 6.3 ± 5.4% p = 0.016) significantly increased from pre- to post-training, independently of condition. The time × group × interval interaction was significant (p = 0.05) for BLa. Compared to Pre-tests, BLa values during post-test were higher (+ 8.7 ± 10.3%) after about 2 in the normoxic group, although statistical significance was not reached (p = 0.08). Contrastingly, BLa values were lower (albeit not significantly) during post- compared to pre-tests after bout 2 (−9.3 ± 8.6%; p = 0.08) and bout 3 (−9.1 ± 10.7%; p = 0.09) in the hypoxic group. In conclusion, six RW training sessions over 2 weeks significantly improved RW performance, while training in hypoxia had no additional benefit over normoxia. However, accompanying BLa responses tended to be lower in the hypoxic group, while an opposite pattern was observed in the normoxic group. This indicates that different glycolytic and/or oxidative pathway adaptations were probably at play.
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Affiliation(s)
- Naoya Takei
- Department of Sports Sciences, The University of Tokyo, Tokyo, Japan.,Murdoch Applied Sports Science Laboratory, Murdoch University, Perth, WA, Australia
| | | | - Olivier Girard
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, WA, Australia
| | - Hideo Hatta
- Department of Sports Sciences, The University of Tokyo, Tokyo, Japan
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17
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Comparison of the Effectiveness of High-Intensity Interval Training in Hypoxia and Normoxia in Healthy Male Volunteers: A Pilot Study. BIOMED RESEARCH INTERNATIONAL 2019; 2019:7315714. [PMID: 31662994 PMCID: PMC6778879 DOI: 10.1155/2019/7315714] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 08/07/2019] [Accepted: 09/05/2019] [Indexed: 01/05/2023]
Abstract
Aims The study investigated the effect of high-intensity interval training in hypoxia and normoxia on serum concentrations of proangiogenic factors, nitric oxide, and inflammatory responses in healthy male volunteers. Methods Twelve physically active male subjects completed a high-intensity interval training (HIIT) in normoxia (NorTr) and in normobaric hypoxia (HypTr) (FiO2 = 15.2%). The effects of HIIT in hypoxia and normoxia on maximal oxygen uptake, hypoxia-inducible factor-1-alpha, vascular endothelial growth factor, nitric oxide, and cytokines were analyzed. Results HIIT in hypoxia significantly increases maximal oxygen uptake (p=0.01) levels compared to pretraining levels. Serum hypoxia-inducible factor-1 (p=0.01) and nitric oxide levels (p=0.05), vascular endothelial growth factor (p=0.04), and transforming growth factor-β (p=0.01) levels were increased in response to exercise test after hypoxic training. There was no effect of training conditions for serum baseline angiogenic factors and cytokines (p > 0.05) with higher HIF-1α and NO levels after hypoxic training compared to normoxic training (F = 9.1; p < 0.01 and F = 5.7; p < 0.05, respectively). Conclusions High-intensity interval training in hypoxia seems to induce beneficial adaptations to exercise mediated via a significant increase in the serum concentrations of proangiogenic factors and serum nitric oxide levels compared to the same training regimen in normoxia.
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18
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Bergholt NL, Olesen ML, Foldager CB. Age-Dependent Systemic Effects of a Systemic Intermittent Hypoxic Therapy In Vivo. High Alt Med Biol 2019; 20:221-230. [PMID: 31260338 DOI: 10.1089/ham.2018.0113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Introduction: The adaptive response to systemic intermittent hypoxic therapy (SIHT) may be used for therapeutic advances due to the activation of multiple pathways involved in angiogenesis, immunomodulation, and tissue homeostasis. The aim of this study was to investigate the early age-dependent systemic response of different exposures of SIHT in mice. Materials and Methods: Sixty-four C57BL/6NRj female mice in three different age groups, young (4-5 weeks), adolescent (8-10 weeks), and adults (23-32 weeks), were exposed to SIHT. Different algorithms for equal hypoxic challenges (oxygen-decrease*time) were investigated to allow examination of the role of absolute hypoxia (oxygen-decrease) compared with relative hypoxia (total oxygen depletion over time). The systemic effects of angiogenetic regulation were investigated using blood samples analyzed by ELISA, proteome profiles, and proximity extension immunoassay. One-way analysis of variance with post hoc Bonferroni analyses was performed. Results: The early systemic response to SIHT was dependent on the absolute hypoxia rather than relative hypoxia over time. Serum erythropoietin (EPO) levels were increased significantly in young mice receiving low-oxygen SIHT treatments (10% and 15% oxygen). The expression of angiogenic proteins differed between the different age groups indicating an age-dependent response to SIHT. Focusing on hypoxia-inducible factor-1 (HIF-1) signaling, there was a trend toward upregulated angiogenetic response with younger age. Furthermore, clustering of protein expression in low-oxygen SIHT algorithms were found between young and adolescent mice. In adult mice, the majority of the proteins were downregulated as a response to SIHT. The systemic response of metabolites expressions was most pronounced in young mice. Systemic levels of cardiac troponin I (Tnni3) was unaffected by SIHT independent of age groups. Conclusions: The systemic response to SIHT is dependent on the absolute hypoxic exposure rather than the relative hypoxic depletion over time. Age-dependent effects of a short-term SIHT were associated with an increase in EPO, upregulation of angiogenetic pathways, and select metabolic and cell-surface proteins.
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Affiliation(s)
- Natasja Leth Bergholt
- Orthopaedic Research Laboratory, Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.,Comparative Medicine Lab, Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Morten Lykke Olesen
- Orthopaedic Research Laboratory, Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Casper Bindzus Foldager
- Orthopaedic Research Laboratory, Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.,Comparative Medicine Lab, Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.,Department of Orthopaedics, Aarhus University Hospital, Aarhus, Denmark
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19
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Suzuki J. Effects of exercise training with short-duration intermittent hypoxia on endurance performance and muscle metabolism in well-trained mice. Physiol Rep 2019; 7:e14182. [PMID: 31328438 PMCID: PMC6643079 DOI: 10.14814/phy2.14182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/19/2019] [Accepted: 06/24/2019] [Indexed: 01/16/2023] Open
Abstract
The author previously reported that short-duration intermittent hypoxia had additive effects on improvements in endurance capacity by enhancing fatty acid metabolism. The present study was designed to investigate the effects of short-duration intermittent hypoxia on endurance capacity, metabolic enzyme activity, and protein levels associated with mitochondrial biogenesis in well-trained mice. Mice in the training group were housed in a cage with a running wheel for 7 weeks from 5 weeks old. Voluntary running markedly increased maximal work values by 5.0-fold. Trained mice were then subjected to either endurance treadmill training (ET) for 60 min or hybrid training (HT, ET for 30 min followed by sprint interval exercise (5-sec run-10-sec rest) for 30 min) with (H-ET or H-HT) or without (ET or HT) short-duration intermittent hypoxia (4 cycles of 12-13% O2 for 15 min and 20.9% O2 for 10 min) for 4 weeks. Maximal endurance capacity was markedly greater in the H-ET and H-HT than ET and HT groups, respectively. H-ET and H-HT increased activity levels of 3-hydroxyacyl-CoA-dehydrogenase in oxidative muscle portion and pyruvate dehydrogenase complex in glycolytic muscle portion. These activity levels were significantly correlated with maximal endurance capacity. Protein levels of dynamin-related protein-1 were increased more by H-ET and H-HT than by ET and HT, but were not significantly correlated with maximal work. These results suggest that intermittent hypoxic exposure has beneficial effects on endurance and hybrid training to improve the endurance capacity via improving fatty acid and pyruvate oxidation in highly trained mice.
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Affiliation(s)
- Junichi Suzuki
- Laboratory of Exercise Physiology, Health and Sports Sciences, Course of Sports Education, Department of EducationHokkaido University of EducationIwamizawaHokkaidoJapan
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20
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Temporal dynamics of pre and post myocardial infarcted tissue with concomitant preconditioning of aerobic exercise in chronic diabetic rats. Life Sci 2019; 225:79-87. [PMID: 30946838 DOI: 10.1016/j.lfs.2019.03.077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 03/27/2019] [Accepted: 03/30/2019] [Indexed: 12/12/2022]
Abstract
The different ailments of heart including myocardial infarction (MI) and ischemic heart diseases are the foremost trigger of high mortality across the world which is instigated by sedentary life style, chronic hyperglycaemia and atherosclerosis. Albeit strenuous exercise itself induces temporary hypoxia which causes myocardial damage and this vitiosus circulus is poorly understood and has been assumed difficult to break. Present investigation targets temporal dynamics of aerobic exercise treatment induced preconditioning against diabetes associated pre- and post- myocardial injury. The persisting high blood sugar level leads to several biochemical alterations at pre- and post-MI phase. Here, we present the assessment of temporal expression of cardiac biomarkers (CKMB, LDH, cTnI and serum nitrite/nitrate), oxidative stress (myocardial TBARS and reduced NBT), inflammatory cytokines (IL-6, TNF-α and IL-10), renal biomarkers (BUN, serum creatinine and microproteinuria) and structural alterations of cardio-renal tissue. Aerobic exercise preconditioning significantly downregulate the pathological events or biomarkers and upsurge the physiological biomarkers at both pre- and post-MI phase. The attenuation or returning of pathological makers to lowest level at different time points endorses the therapeutic management of aerobic exercise against diabetic MI. Furthermore, the temporal expression of various cardio-renal biomarkers pattern elucidates that aerobic exercise preconditioning boost the strength and consolidate the cardiac muscles to work under stress. Despite the presence of traditional knowledge about health benefits of aerobic exercise, it is yet to be brought into the clinical arena. In spite of few impending challenges subjected to additional investigations, aerobic exercise preconditioning shows a high degree of promise.
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Entrenamiento de fuerza y resistencia en hipoxia: efecto en la hipertrofia muscular. BIOMEDICA 2019; 39:212-220. [PMID: 31021559 DOI: 10.7705/biomedica.v39i1.4084] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Indexed: 02/07/2023]
Abstract
El entrenamiento en altitud y el entrenamiento en hipoxia simulada producen adaptaciones fisiológicas y bioquímicas en el músculo esquelético como la capacidad oxidativa, así como modificaciones de la actividad mitocondrial, en el metabolismo aerobio y en el contenido de mioglobina.El propósito de esta revisión fue analizar las adaptaciones del músculo esquelético en respuesta a la exposición temporal a la hipoxia combinada con ejercicios de fuerza y resistencia. Según los hallazgos de numerosos autores, las adaptaciones estructurales del músculo son similares en la hipoxia y en la ‘normoxia’, con excepción de un aumento en el volumen muscular y en el área de la sección transversal de la fibra muscular, que son mayores en la hipoxia.En conclusión, la sinergia del entrenamiento de fuerza y resistencia y la hipoxia normobárica produce mejores y mayores adaptaciones, ganancias y cambios fisiológicos beneficiosos en el tejido muscular, lo cual genera cambios fenotípicos favorables, como la hipertrofia del músculo esquelético.
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22
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Wang R, Guo S, Tian H, Huang Y, Yang Q, Zhao K, Kuo CH, Hong S, Chen P, Liu T. Hypoxic Training in Obese Mice Improves Metabolic Disorder. Front Endocrinol (Lausanne) 2019; 10:527. [PMID: 31440207 PMCID: PMC6694298 DOI: 10.3389/fendo.2019.00527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/17/2019] [Indexed: 12/29/2022] Open
Abstract
Hypoxic training has been reported to lower obesity morbidity without clear underlying mechanisms. This study investigates the effect of hypoxic training on metabolic changes, particularly, on liver metabolism of high fat diet (HFD)-induced obese mice. We compared the hypoxic training group with normoxic sedentary, normoxic training, and hypoxic sedentary groups. Body weight, fat mass, glucose tolerance and liver physiology were determined after 4 weeks intervention. In both normoxic training and hypoxic training groups, body weight was lower than the normoxic sedentary group, with less fat mass. Insulin sensitivity was improved after hypoxic training. Moreover, liver metabolomics revealed insights into the protective effect of hypoxic training on HFD-induced fatty liver. Taken together, these findings provide a molecular metabolic mechanism for hypoxic training.
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Affiliation(s)
- Ru Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- *Correspondence: Ru Wang
| | - Shanshan Guo
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Haili Tian
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Yiru Huang
- State Key Laboratory of Genetic Engineering, Department of Endocrinology and Metabolism, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
| | - Qin Yang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Kewei Zhao
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Chia-Hua Kuo
- Laboratory of Exercise Biochemistry, University of Taipei, Taipei, Taiwan
| | - Shangyu Hong
- State Key Laboratory of Genetic Engineering, Department of Endocrinology and Metabolism, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Peijie Chen
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- Peijie Chen
| | - Tiemin Liu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- State Key Laboratory of Genetic Engineering, Department of Endocrinology and Metabolism, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
- Tiemin Liu
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23
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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.
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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
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Chacaroun S, Vega-Escamilla Y Gonzalez I, Flore P, Doutreleau S, Verges S. Physiological responses to hypoxic constant-load and high-intensity interval exercise sessions in healthy subjects. Eur J Appl Physiol 2018; 119:123-134. [PMID: 30315366 DOI: 10.1007/s00421-018-4006-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 10/03/2018] [Indexed: 12/11/2022]
Abstract
PURPOSE The aim of this study was to assess the acute cardiorespiratory as well as muscle and cerebral tissue oxygenation responses to submaximal constant-load (CL) and high-intensity interval (HII) cycling exercise performed in normoxia and in hypoxia at similar intensity, reproducing whole-body endurance exercise training sessions as performed in sedentary and clinical populations. METHODS Healthy subjects performed two CL (30 min, 75% of maximal heart rate, n = 12) and two HII (15 times 1-min high-intensity exercise-1-min passive recovery, n = 12) cycling exercise sessions in normoxia and in hypoxia [mean arterial oxygen saturation 76 ± 1% (clamped) during CL and 77 ± 5% (inspiratory oxygen fraction 0.135) during HII]. Cardiorespiratory and near-infrared spectroscopy parameters as well as the rate of perceived exertion were continuously recorded. RESULTS Power output was 21 ± 11% and 15% (according to protocol design) lower in hypoxia compared to normoxia during CL and HII exercise sessions, respectively. Heart rate did not differ between normoxic and hypoxic exercise sessions, while minute ventilation was higher in hypoxia during HII exercise only (+ 13 ± 29%, p < 0.05). Quadriceps tissue saturation index did not differ significantly between normoxia and hypoxia (CL 60 ± 8% versus 59 ± 5%; HII 59 ± 10% versus 56 ± 9%; p > 0.05), while prefrontal cortex deoxygenation was significantly greater in hypoxia during both CL (66 ± 4% versus 56 ± 6%) and HII (58 ± 5% versus 55 ± 5%; p < 0.05) sessions. The rate of perceived exertion did not differ between normoxic and hypoxic CL (2.4 ± 1.7 versus 2.9 ± 1.8) and HII (6.9 ± 1.4 versus 7.5 ± 0.8) sessions (p > 0.05). CONCLUSION This study indicates that at identical heart rate, reducing arterial oxygen saturation near 75% does not accentuate muscle deoxygenation during both CL and HII exercise sessions compared to normoxia. Hence, within these conditions, larger muscle hypoxic stress should not be expected.
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Affiliation(s)
- S Chacaroun
- HP2 Laboratory, INSERM U1042, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Avenue Kimberley, 38 434, Echirolles, France
| | - I Vega-Escamilla Y Gonzalez
- HP2 Laboratory, INSERM U1042, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Avenue Kimberley, 38 434, Echirolles, France
| | - P Flore
- HP2 Laboratory, INSERM U1042, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Avenue Kimberley, 38 434, Echirolles, France
| | - S Doutreleau
- HP2 Laboratory, INSERM U1042, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Avenue Kimberley, 38 434, Echirolles, France.,Grenoble Alpes University Hospital, Grenoble, France
| | - Samuel Verges
- HP2 Laboratory, INSERM U1042, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Avenue Kimberley, 38 434, Echirolles, France. .,Grenoble Alpes University Hospital, Grenoble, France.
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25
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Andrade DC, Beltrán AR, Labarca-Valenzuela C, Manzo-Botarelli O, Trujillo E, Otero-Farias P, Álvarez C, Garcia-Hermoso A, Toledo C, Del Rio R, Silva-Urra J, Ramírez-Campillo R. Effects of Plyometric Training on Explosive and Endurance Performance at Sea Level and at High Altitude. Front Physiol 2018; 9:1415. [PMID: 30364035 PMCID: PMC6191644 DOI: 10.3389/fphys.2018.01415] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 09/18/2018] [Indexed: 01/16/2023] Open
Abstract
Plyometric training performed at sea level enhance explosive and endurance performance at sea level. However, its effects on explosive and endurance performance at high altitude had not been studied. Therefore, the aim of this study was to determine the effects of a sea level short-term (i.e., 4-week) plyometric training program on explosive and endurance performance at sea level and at high altitude (i.e., 3,270 m above sea level). Participants were randomly assigned to a control group (n = 12) and a plyometric training group (n = 11). Neuromuscular (reactive strength index – RSI) and endurance (2-km time-trial; running economy [RE]; maximal oxygen uptake - VO2max) measurements were performed at sea level before, at sea level after intervention (SL +4 week), and at high altitude 24-h post SL +4 week. The ANOVA revealed that at SL +4 week the VO2max was not significantly changed in any group, although RE, RSI and 2-km time trial were significantly (p < 0.05) improved in the plyometric training group. After training, when both groups were exposed to high altitude, participants from the plyometric training group showed a greater RSI (p < 0.05) and were able to maintain their 2-km time trial (11.3 ± 0.5 min vs. 10.7 ± 0.6 min) compared to their pre-training sea level performance. In contrast, the control group showed no improvement in RSI, with a worse 2-km time trial performance (10.3 ± 0.8 min vs. 9.02 ± 0.64 min; p < 0.05; ES = 0.13). Moreover, after training, both at sea level and at high altitude the plyometric training group demonstrated a greater (p < 0.05) RSI and 2-km time trial performance compared to the control group. The oxygen saturation was significantly decreased after acute exposure to high altitude in the two groups (p < 0.05). These results confirm the beneficial effects of sea level short-term plyometric training on explosive and endurance performance at sea level. Moreover, current results indicates that plyometric training may also be of value for endurance athletes performing after an acute exposure to high altitude.
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Affiliation(s)
- David Cristóbal Andrade
- Laboratory of Cardiorespiratory Control, Faculty of Physiological Science, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación en Fisiología del Ejercicio, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Ana Rosa Beltrán
- Departamento de Educación, Facultad de Educación, Universidad de Antofagasta, Antofagasta, Chile
| | - Cristian Labarca-Valenzuela
- Departamento Biomédico, Centro Investigación en Fisiología y Medicina de Altura, Universidad de Antofagasta, Antofagasta, Chile
| | - Oscar Manzo-Botarelli
- Departamento Biomédico, Centro Investigación en Fisiología y Medicina de Altura, Universidad de Antofagasta, Antofagasta, Chile
| | - Erwin Trujillo
- Departamento Biomédico, Centro Investigación en Fisiología y Medicina de Altura, Universidad de Antofagasta, Antofagasta, Chile
| | - Patricio Otero-Farias
- Departamento de Educación, Facultad de Educación, Universidad de Antofagasta, Antofagasta, Chile
| | - Cristian Álvarez
- Department of Physical Activity Sciences, Research Nucleus in Health, Physical Activity and Sport, Quality of Life and Wellness Research Group, Universidad de Los Lagos, Osorno, Chile
| | - Antonio Garcia-Hermoso
- Laboratorio de Ciencias de la Actividad Física, el Deporte y la Salud, Universidad de Santiago de Chile, Santiago, Chile
| | - Camilo Toledo
- Laboratory of Cardiorespiratory Control, Faculty of Physiological Science, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rodrigo Del Rio
- Laboratory of Cardiorespiratory Control, Faculty of Physiological Science, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Excelencia en Biomedicina de Magallanes, Universidad de Magallanes, Punta Arenas, Chile.,Centro de Envejecimiento y Regeneración, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Silva-Urra
- Departamento Biomédico, Centro Investigación en Fisiología y Medicina de Altura, Universidad de Antofagasta, Antofagasta, Chile
| | - Rodrigo Ramírez-Campillo
- Department of Physical Activity Sciences, Research Nucleus in Health, Physical Activity and Sport, Quality of Life and Wellness Research Group, Universidad de Los Lagos, Osorno, Chile
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26
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Mourot L. Limitation of Maximal Heart Rate in Hypoxia: Mechanisms and Clinical Importance. Front Physiol 2018; 9:972. [PMID: 30083108 PMCID: PMC6064954 DOI: 10.3389/fphys.2018.00972] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/02/2018] [Indexed: 12/17/2022] Open
Abstract
The use of exercise intervention in hypoxia has grown in popularity amongst patients, with encouraging results compared to similar intervention in normoxia. The prescription of exercise for patients largely rely on heart rate recordings (percentage of maximal heart rate (HRmax) or heart rate reserve). It is known that HRmax decreases with high altitude and the duration of the stay (acclimatization). At an altitude typically chosen for training (2,000-3,500 m) conflicting results have been found. Whether or not this decrease exists or not is of importance since the results of previous studies assessing hypoxic training based on HR may be biased due to improper intensity. By pooling the results of 86 studies, this literature review emphasizes that HRmax decreases progressively with increasing hypoxia. The dose–response is roughly linear and starts at a low altitude, but with large inter-study variabilities. Sex or age does not seem to be a major contributor in the HRmax decline with altitude. Rather, it seems that the greater the reduction in arterial oxygen saturation, the greater the reduction in HRmax, due to an over activity of the parasympathetic nervous system. Only a few studies reported HRmax at sea/low level and altitude with patients. Altogether, due to very different experimental design, it is difficult to draw firm conclusions in these different clinical categories of people. Hence, forthcoming studies in specific groups of patients are required to properly evaluate (1) the HRmax change during acute hypoxia and the contributing factors, and (2) the physiological and clinical effects of exercise training in hypoxia with adequate prescription of exercise training intensity if based on heart rate.
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Affiliation(s)
- Laurent Mourot
- EA 3920 Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation Platform, University of Franche-Comté, Besançon, France.,Tomsk Polytechnic University, Tomsk, Russia
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27
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Przyklenk A, Aussieker T, Gutmann B, Schiffer T, Brinkmann C, Strüder HK, Bloch W, Mierau A, Gehlert S. Effects of Endurance Exercise Bouts in Hypoxia, Hyperoxia, and Normoxia on mTOR-Related Protein Signaling in Human Skeletal Muscle. J Strength Cond Res 2018; 34:2276-2284. [PMID: 30024485 DOI: 10.1519/jsc.0000000000002753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Przyklenk, A, Aussieker, T, Gutmann, B, Schiffer, T, Brinkmann, C, Strüder, HK, Bloch, W, Mierau, A, and Gehlert, S. Effects of endurance exercise bouts in hypoxia, hyperoxia, and normoxia on mTOR-related protein signaling in human skeletal muscle. J Strength Cond Res 34(8): 2276-2284, 2020-This study investigated the effects of short-term hypoxia (HY), hyperoxia (PER), and normoxia on anabolic signaling proteins in response to an acute bout of moderate endurance exercise (EEX) before and after an endurance exercise training intervention. Eleven healthy male subjects conducted one-legged cycling endurance exercise (3 × 30 min·wk for 4 weeks). One leg was trained under hypoxic (12% O2) or hyperoxic conditions (in a randomized cross-over design), and the other leg was trained in normoxia (20.9% O2) at the same relative workload. Musculus vastus lateralis biopsies were taken at baseline (T0) as well as immediately after the first (T1) and last (T2) training session to analyze anabolic signaling proteins and the myofiber cross-sectional area (FCSA). No significant differences were detected for FCSA between T0 and T2 under all oxygen conditions (p > 0.05). No significant differences (p > 0.05) were observed for BNIP3, phosphorylated RSK1, ERK1/2, FoxO3a, mTOR, and S6K1 between all conditions and time points. Phosphorylated Akt/PKB decreased significantly (p < 0.05) at T1 in PER and at T2 in HY and PER. Phosphorylated rpS6 decreased significantly (p < 0.05) at T1 only in PER, whereas nonsignificant increases were shown in HY at T2 (p = 0.10). Despite no significant regulations, considerable reductions in eEF2 phosphorylation were detected in HY at T1 and T2 (p = 0.11 and p = 0.12, respectively). Short-term hypoxia in combination with moderate EEX induces favorable acute anabolic signaling responses in human skeletal muscle.
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Affiliation(s)
- Axel Przyklenk
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany
| | - Thorben Aussieker
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany
| | - Boris Gutmann
- Institute of Movement and Neuroscience, German Sport University Cologne, Cologne, Germany
| | - Thorsten Schiffer
- Outpatient Clinic for Sports Traumatology and Public Health Consultation, German Sport University Cologne, Cologne, Germany
| | - Christian Brinkmann
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany
| | - Heiko K Strüder
- Institute of Movement and Neuroscience, German Sport University Cologne, Cologne, Germany
| | - Wilhelm Bloch
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany
| | - Andreas Mierau
- Institute of Movement and Neuroscience, German Sport University Cologne, Cologne, Germany.,Department of Exercise and Sport Science, LUNEX International University of Health, Exercise and Sports, Differdange, Luxembourg; and
| | - Sebastian Gehlert
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany.,Department of Sport Science, University of Hildesheim, Hildesheim, Germany
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28
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Rizo-Roca D, Bonet JB, Ínal B, Ríos-Kristjánsson JG, Pagès T, Viscor G, Torrella JR. Contractile Activity Is Necessary to Trigger Intermittent Hypobaric Hypoxia-Induced Fiber Size and Vascular Adaptations in Skeletal Muscle. Front Physiol 2018; 9:481. [PMID: 29780328 PMCID: PMC5945885 DOI: 10.3389/fphys.2018.00481] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/16/2018] [Indexed: 01/20/2023] Open
Abstract
Altitude training has become increasingly popular in recent decades. Its central and peripheral effects are well-described; however, few studies have analyzed the effects of intermittent hypobaric hypoxia (IHH) alone on skeletal muscle morphofunctionality. Here, we studied the effects of IHH on different myofiber morphofunctional parameters, investigating whether contractile activity is required to elicit hypoxia-induced adaptations in trained rats. Eighteen male Sprague-Dawley rats were trained 1 month and then divided into three groups: (1) rats in normobaria (trained normobaric inactive, TNI); (2) rats subjected daily to a 4-h exposure to hypobaric hypoxia equivalent to 4,000 m (trained hypobaric inactive, THI); and (3) rats subjected daily to a 4-h exposure to hypobaric hypoxia just before performing light exercise (trained hypobaric active, THA). After 2 weeks, the tibialis anterior muscle (TA) was excised. Muscle cross-sections were stained for: (1) succinate dehydrogenase to identify oxidative metabolism; (2) myosin-ATPase to identify slow- and fast-twitch fibers; and (3) endothelial-ATPase to stain capillaries. Fibers were classified as slow oxidative (SO), fast oxidative glycolytic (FOG), fast intermediate glycolytic (FIG) or fast glycolytic (FG) and the following parameters were measured: fiber cross-sectional area (FCSA), number of capillaries per fiber (NCF), NCF per 1,000 μm2 of FCSA (CCA), fiber and capillary density (FD and CD), and the ratio between CD and FD (C/F). THI rats did not exhibit significant changes in most of the parameters, while THA animals showed reduced fiber size. Compared to TNI rats, FOG fibers from the lateral/medial fields, as well as FIG and FG fibers from the lateral region, had smaller FCSA in THA rats. Moreover, THA rats had increased NCF in FG fibers from all fields, in medial and posterior FIG fibers and in posterior FOG fibers. All fiber types from the three analyzed regions (except the posterior FG fibers) displayed a significantly increased CCA ratio compared to TNI rats. Global capillarisation was also increased in lateral and medial fields. Our results show that IHH alone does not induce alterations in the TA muscle. The inclusion of exercise immediately after the tested hypoxic conditions is enough to trigger a morphofunctional response that improves muscle capillarisation.
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Affiliation(s)
- David Rizo-Roca
- Unitat de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.,LaMetEx - Laboratory of Metabolism and Exercise, Faculty of Sport Sciences, University of Porto, Porto, Portugal
| | - Jèssica B Bonet
- Unitat de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Büsra Ínal
- Unitat de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Juan Gabriel Ríos-Kristjánsson
- Unitat de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Teresa Pagès
- Unitat de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Ginés Viscor
- Unitat de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Joan R Torrella
- Unitat de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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29
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Autophagy Is a Promoter for Aerobic Exercise Performance during High Altitude Training. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:3617508. [PMID: 29849885 PMCID: PMC5907404 DOI: 10.1155/2018/3617508] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/10/2018] [Accepted: 03/15/2018] [Indexed: 01/10/2023]
Abstract
High altitude training is one of the effective strategies for improving aerobic exercise performance at sea level via altitude acclimatization, thereby improving oxygen transport and/or utilization. But its underlying molecular mechanisms on physiological functions and exercise performance of athletes are still vague. More recent evidence suggests that the recycling of cellular components by autophagy is an important process of the body involved in the adaptive responses to exercise. Whether high altitude training can activate autophagy or whether high altitude training can improve exercise performance through exercise-induced autophagy is still unclear. In this narrative review article, we will summarize current research advances in the improvement of exercise performance through high altitude training and its reasonable molecular mechanisms associated with autophagy, which will provide a new field to explore the molecular mechanisms of adaptive response to high altitude training.
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30
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Klarod K, Philippe M, Gatterer H, Burtscher M. Different training responses to eccentric endurance exercise at low and moderate altitudes in pre-diabetic men: a pilot study. SPORT SCIENCES FOR HEALTH 2017; 13:615-623. [PMID: 29276542 PMCID: PMC5729199 DOI: 10.1007/s11332-017-0392-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 08/11/2017] [Indexed: 12/19/2022]
Abstract
This pilot study aimed (a) to evaluate the effects of eccentric exercise training at low and moderate altitudes on physical fitness in pre-diabetic men and (b) to establish whether or not oxidative stress levels and antioxidant status were associated with performance improvements. In this crossover trial, five pre-diabetic men conducted nine downhill walking sessions (3 days/week, 3 consecutive weeks) at low altitude (from 1360 to 850 m) and one year later at moderate altitude (from 2447 to 2000 m). Exercise testing and the determination of parameters of oxidative stress and antioxidant capacity were performed pre- and post-training. The biological antioxidant activity of plasma (BAP) increased after eccentric training at moderate altitude (p < 0.001), whereas diacron reactive oxygen metabolites (dROMs) remained unchanged. Also, the BAP/dROMs ratio increased only after training at moderate-altitude training (p = 0.009). Maximum power output improved after training at low altitude and the changes were significantly related to baseline BAP/dROMs ratio (r = 0.90). No decrease was seen for fasting plasma glucose. Eccentric exercise training in pre-diabetic men improved performance only when performed at low altitude and this improvement was positively related to the baseline BAP/dROMs ratio. In contrast, 3 weeks of eccentric exercise training increased BAP levels and the BAP/dROMs ratio only at moderate altitude without improving the performance. Thus, one might speculate that the BAP/dROMs ratio has to increase before performance improvements occur at moderate altitude.
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Affiliation(s)
- Kultida Klarod
- Department of Sport Science, Medical Section, University of Innsbruck, 6020 Innsbruck, Austria.,Department of Physical Therapy, Faculty of Allied Health Sciences, Burapha University, Chonburi, 20131 Thailand
| | - Marc Philippe
- Department of Sport Science, Medical Section, University of Innsbruck, 6020 Innsbruck, Austria.,Department of Sports Medicine, Institute of Sports Sciences, Justus-Liebig-University, 35394 Giessen, Germany
| | - Hannes Gatterer
- Department of Sport Science, Medical Section, University of Innsbruck, 6020 Innsbruck, Austria
| | - Martin Burtscher
- Department of Sport Science, Medical Section, University of Innsbruck, 6020 Innsbruck, Austria
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Czuba M, Wilk R, Karpiński J, Chalimoniuk M, Zajac A, Langfort J. Intermittent hypoxic training improves anaerobic performance in competitive swimmers when implemented into a direct competition mesocycle. PLoS One 2017; 12:e0180380. [PMID: 28763443 PMCID: PMC5538675 DOI: 10.1371/journal.pone.0180380] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 06/14/2017] [Indexed: 11/18/2022] Open
Abstract
The main objective of this research was to evaluate the efficacy of intermittent hypoxic training (IHT) on anaerobic and aerobic capacity and swimming performance in well-trained swimmers. Sixteen male swimmers were randomly divided into a hypoxia (H) group (n = 8), which trained in a normobaric hypoxia environment, and a control (C) group (n = 8), which exercised under normoxic conditions. However, one participant left the study without explanation. During the experiment group H trained on land twice per week in simulated hypoxia (FiO2 = 15.5%, corresponding to 2,500 m a.s.l); however, they conducted swim training in normoxic conditions. Group C performed the same training program under normoxic conditions. The training program included four weekly microcyles, followed by three days of recovery. During practice sessions on land, the swimmers performed 30 second sprints on an arm-ergometer, alternating with two minute high intensity intervals on a lower limb cycle ergometer. The results showed that the training on land caused a significant (p<0.05) increase in absolute maximal workload (WRmax) by 7.4% in group H and by 3.2% in group C and relative values of VO2max by 6.9% in group H and 3.7% in group C. However, absolute values of VO2max were not significantly changed. Additionally, a significant (p<0.05) increase in mean power (Pmean) during the first (11.7%) and second (11.9%) Wingate tests was only observed in group H. The delta values of lactate concentration (ΔLA) after both Wingate tests were significantly (p<0.05) higher in comparison to baseline levels by 28.8% in group H. Opposite changes were observed in delta values of blood pH (ΔpH) after both Wingate tests in group H, with a significant decrease in values of ΔpH by 33.3%. The IHT caused a significant (p<0.05) improvement in 100m and 200m swimming performance, by 2.1% and 1.8%, respectively in group H. Training in normoxia (group C), resulted in a significant (p<0.05) improvement of swimming performance at 100m and 200m, by 1.1% and 0.8%, respectively. In conclusion, the most important finding of this study includes a significant improvement in anaerobic capacity and swimming performance after high-intensity IHT. However, this training protocol had no effect on absolute values of VO2max and hematological variables.
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Affiliation(s)
- Miłosz Czuba
- Department of Sports Training, the Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education, Katowice, Poland
- * E-mail:
| | - Robert Wilk
- Department of Swimming, the Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education, Katowice, Poland
| | - Jakub Karpiński
- Department of Swimming, the Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education, Katowice, Poland
| | - Małgorzata Chalimoniuk
- Department of Tourism and Health in Biala Podlaska, Józef Piłsudski University of Physical Education in Warsaw, Warsaw, Poland
| | - Adam Zajac
- Department of Sports Training, the Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education, Katowice, Poland
| | - Józef Langfort
- Department of Sports Training, the Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education, Katowice, Poland
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Córdova Martínez A, Pascual Fernández J, Fernandez Lázaro D, Alvarez Mon M. Muscular and heart adaptations of execise in hypoxia. Is training in slow hypoxy healthy? Med Clin (Barc) 2017; 148:469-474. [PMID: 28341369 DOI: 10.1016/j.medcli.2017.02.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/02/2017] [Accepted: 02/09/2017] [Indexed: 12/22/2022]
Affiliation(s)
- Alfredo Córdova Martínez
- Departamento de Bioquímica, Biología Molecular y Fisiología, Facultad de Fisioterapia, Campus Universitario de Soria, Universidad de Valladolid, Soria, España.
| | | | - Diego Fernandez Lázaro
- Departamento de Bioquímica, Biología Molecular y Fisiología, Facultad de Fisioterapia, Campus Universitario de Soria, Universidad de Valladolid, Soria, España
| | - Melchor Alvarez Mon
- Departamento de Medicina y Especialidades Médicas, Hospital Universitario Príncipe de Asturias, Universidad de Alcalá, Alcalá de Henares, Madrid, España
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Spielman LJ, Estaki M, Ghosh S, Gibson DL, Klegeris A. The effects of voluntary wheel running on neuroinflammatory status: Role of monocyte chemoattractant protein-1. Mol Cell Neurosci 2017; 79:93-102. [DOI: 10.1016/j.mcn.2016.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/30/2016] [Indexed: 12/17/2022] Open
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Rizo-Roca D, Ríos-Kristjánsson JG, Núñez-Espinosa C, Santos-Alves E, Gonçalves IO, Magalhães J, Ascensão A, Pagès T, Viscor G, Torrella JR. Intermittent hypobaric hypoxia combined with aerobic exercise improves muscle morphofunctional recovery after eccentric exercise to exhaustion in trained rats. J Appl Physiol (1985) 2016; 122:580-592. [PMID: 27765844 DOI: 10.1152/japplphysiol.00501.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/27/2016] [Accepted: 10/13/2016] [Indexed: 01/07/2023] Open
Abstract
Unaccustomed eccentric exercise leads to muscle morphological and functional alterations, including microvasculature damage, the repair of which is modulated by hypoxia. We present the effects of intermittent hypobaric hypoxia and exercise on recovery from eccentric exercise-induced muscle damage (EEIMD). Soleus muscles from trained rats were excised before (CTRL) and 1, 3, 7, and 14 days after a double session of EEIMD protocol. A recovery treatment consisting of one of the following protocols was applied 1 day after the EEIMD: passive normobaric recovery (PNR), a 4-h daily exposure to passive hypobaric hypoxia at 4,000 m (PHR), or hypobaric hypoxia exposure followed by aerobic exercise (AHR). EEIMD produced an increase in the percentage of abnormal fibers compared with CTRL, and it affected the microvasculature by decreasing capillary density (CD, capillaries per mm2) and the capillary-to-fiber ratio (CF). After 14 days, AHR exhibited CD and CF values similar to those of CTRL animals (789 and 3.30 vs. 746 and 3.06) and significantly higher than PNR (575 and 2.62) and PHR (630 and 2.92). Furthermore, VEGF expression showed a significant 43% increase in AHR when compared with PNR. Moreover, after 14 days, the muscle fibers in AHR had a more oxidative phenotype than the other groups, with significantly smaller cross-sectional areas (AHR, 3,745; PNR, 4,502; and PHR, 4,790 µm2), higher citrate synthase activity (AHR, 14.8; PNR, 13.1; and PHR, 12 µmol·min-1·mg-1) and a significant 27% increment in PGC-1α levels compared with PNR. Our data show that hypoxia combined with exercise attenuates or reverses the morphofunctional alterations induced by EEIMD.NEW & NOTEWORTHY Our study provides new insights into the use of intermittent hypobaric hypoxia combined with exercise as a strategy to recover muscle damage induced by eccentric exercise. We analyzed the effects of hypobaric exposure combined with aerobic exercise on histopathological features of muscle damage, fiber morphofunctionality, capillarization, angiogenesis, and the oxidative capacity of damaged soleus muscle. Most of these parameters were improved after a 2-wk protocol of intermittent hypobaric hypoxia combined with aerobic exercise.
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Affiliation(s)
- D Rizo-Roca
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - J G Ríos-Kristjánsson
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - C Núñez-Espinosa
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - E Santos-Alves
- Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - I O Gonçalves
- Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - J Magalhães
- Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - A Ascensão
- Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - T Pagès
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - G Viscor
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - J R Torrella
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
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Effect of High-Intensity Training in Normobaric Hypoxia on Thoroughbred Skeletal Muscle. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:1535367. [PMID: 27721912 PMCID: PMC5046030 DOI: 10.1155/2016/1535367] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 07/11/2016] [Accepted: 08/16/2016] [Indexed: 11/17/2022]
Abstract
Hypoxic training is believed to increase endurance capacity in association with hypoxia inducible factor-1α (HIF-1α), a modulator of vascular endothelial growth factor-A (VEGF-A), and to influence activation of satellite cells (SCs). However, the effect of hypoxic training on SC activation and its relation to angiogenesis has not been thoroughly investigated. Eight Thoroughbred horses were subjected to normoxic (FIO2 = 21%) or hypoxic (FIO2 = 15%) training for 3 days/week (100% [Formula: see text]) for 4 weeks. Incremental exercise tests (IET) were conducted on a treadmill under normoxia and the maximal oxygen consumption ([Formula: see text]) and running distance were measured before and after each training session. Muscle biopsy samples were obtained from the gluteus medius muscle at 6 scheduled times before, during, and one week after IET for immunohistochemical analysis and real-time RT-PCR analysis. Running distance and [Formula: see text], measured during IET, increased significantly after hypoxic training compared with normoxic training. Capillary density and mRNA expression related to SC activation (e.g., myogenin and hepatocyte growth factor) and angiogenesis (VEGF-A) increased only after hypoxic training. These results suggest that increases in mRNA expression after training enhance and prolong SC activation and angiogenesis and that nitric oxide plays an important role in these hypoxia-induced training effects.
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Suzuki J. Short-duration intermittent hypoxia enhances endurance capacity by improving muscle fatty acid metabolism in mice. Physiol Rep 2016; 4:4/7/e12744. [PMID: 27044851 PMCID: PMC4831319 DOI: 10.14814/phy2.12744] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 02/29/2016] [Indexed: 12/20/2022] Open
Abstract
This study was designed to (1) investigate the effects of acute short-duration intermittent hypoxia on musclemRNAand microRNAexpression levels; and (2) clarify the mechanisms by which short-duration intermittent hypoxia improves endurance capacity. Experiment-1: Male mice were subjected to either acute 1-h hypoxia (12% O2), acute short-duration intermittent hypoxia (12% O2for 15 min, room air for 10 min, 4 times, Int-Hypo), or acute endurance exercise (Ex). The expression of vascular endothelial growth factor-AmRNAwas significantly greater than the control at 0 h post Ex and 6 h post Int-Hypo in the deep red region of the gastrocnemius muscle. miR-16 expression levels were significantly lower at 6 and 10 h post Int-Hypo. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)mRNAlevels were significantly greater than the control at 3 h post Ex and 6 h post Int-Hypo. miR-23a expression levels were lower than the control at 6-24 h post Int-Hypo. Experiment-2: Mice were subjected to normoxic exercise training with or without intermittent hypoxia for 3 weeks. Increases in maximal exercise capacity were significantly greater by training with short-duration intermittent hypoxia (IntTr) than without hypoxia. Both 3-Hydroxyacyl-CoA-dehydrogenase and total carnitine palmitoyl transferase activities were significantly enhanced in IntTr. Peroxisome proliferator-activated receptor delta andPGC-1α mRNAlevels were both significantly greater in IntTr than in the sedentary controls. These results suggest that exercise training under normoxic conditions with exposure to short-duration intermittent hypoxia represents a beneficial strategy for increasing endurance performance by enhancing fatty acid metabolism in skeletal muscle.
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Affiliation(s)
- Junichi Suzuki
- Laboratory of Exercise Physiology, Health and Sports Sciences, Course of Sports Education, Department of Education, Hokkaido University of Education, Midorigaoka, Iwamizawa, Hokkaido, 068-8642, Japan
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Park HY, Hwang H, Park J, Lee S, Lim K. The effects of altitude/hypoxic training on oxygen delivery capacity of the blood and aerobic exercise capacity in elite athletes - a meta-analysis. J Exerc Nutrition Biochem 2016; 20:15-22. [PMID: 27298808 PMCID: PMC4899894 DOI: 10.20463/jenb.2016.03.20.1.3] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 03/02/2016] [Accepted: 03/03/2016] [Indexed: 11/22/2022] Open
Abstract
PURPOSE This study was designed as a meta-analysis of randomized controlled trials comparing effectiveness of altitude/hypoxic training (experimental) versus sea-level training (control) on oxygen delivery capacity of the blood and aerobic exercise capacity of elite athletes in Korea. METHODS Databases (Research Information Service System, Korean studies Information Service System, National Assembly Library) were for randomized controlled trials comparing altitude/hypoxic training versus sea-level training in elite athletes. Studies published in Korea up to December 2015 were eligible for inclusion. Oxygen delivery capacity of the blood was quantified by red blood cell (RBC), hemoglobin (Hb), hematocrit (Hct), erythropoietin (EPO); and aerobic exercise capacity was quantified by maximal oxygen consumption (VO2max). RBC, Hb, Hct, VO2max represented heterogeneity and compared post-intervention between altitude/hypoxic training and sea-level training in elite athletes by a random effect model meta-analysis. EPO represented homogeneity and meta-analysis performed by a fixed effect model. Eight independent studies with 156 elite athletes (experimental: n = 82, control: n = 74) were included in the metaanalysis. RESULTS RBC (4.499×10(5) cell/ul, 95 % CI: 2.469 to 6.529), Hb (5.447 g/dl, 95 % CI: 3.028 to 7.866), Hct (3.639 %, 95 % CI: 1.687 to 5.591), EPO (0.711 mU/mL, 95% CI: 0.282 to 1.140), VO2max (1.637 ml/kg/min, 95% CI: 0.599 to 1.400) showed significantly greater increase following altitude/hypoxic training, as compared with sea-level training. CONCLUSION For elite athletes in Korea, altitude/ hypoxic training appears more effective than sea-level training for improvement of oxygen delivery capacity of the blood and aerobic exercise capacity.
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Affiliation(s)
- Hun-Young Park
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul Republic of Korea
| | - Hyejung Hwang
- Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul Republic of Korea
| | - Jonghoon Park
- Department of Physical Education, Korea University, Seoul Republic of Korea
| | - Seongno Lee
- Department of Physical Education, Hanyang University, Seoul Republic of Korea
| | - Kiwon Lim
- Physical Activity and Performance Institute (PAPI), Konkuk University, SeoulRepublic of Korea; Department of Physical Education, Konkuk University, SeoulRepublic of Korea
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Schega L, Peter B, Brigadski T, Leßmann V, Isermann B, Hamacher D, Törpel A. Effect of intermittent normobaric hypoxia on aerobic capacity and cognitive function in older people. J Sci Med Sport 2016; 19:941-945. [PMID: 27134133 DOI: 10.1016/j.jsams.2016.02.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 02/19/2016] [Accepted: 02/22/2016] [Indexed: 01/19/2023]
Abstract
OBJECTIVES Physical exercise, especially aerobic training, improves physical performance and cognitive function of older people. Furthermore, it has been speculated that age-associated deteriorations in physical performance and cognitive function could be counteracted through exposures to passive intermittent normobaric hypoxia (IH). Thus, the present investigation aimed at investigating the effect of passive IH combined with subsequent aerobic training on hematological parameters and aerobic physical performance (V˙O2max) as well as peripheral levels of the neurotrophin brain-derived neurotrophic factor (BDNF) and cognitive function. DESIGN Randomized controlled trial in a repeated measure design. METHODS 34 older participants were randomly assigned to an intervention group (IG) or control group (CG). While IG was supplied with passive IH for 90min, CG breathed ambient air. Subsequently, both groups underwent 30min of aerobic training three times per week for four consecutive weeks. Aerobic physical performance and cognitive function was tested with spiroergometry and the Stroop test. Blood samples were taken to measure hematological parameters and the peripheral serum BDNF-level. RESULTS We found increases in the values of hematological parameters, the time to exhaustion in the load test and an augmented and sustainable improvement in cognitive function within the IG of the older people only. However, in both groups, the V˙O2max and serum BDNF-level did not increase. CONCLUSIONS Based on these results, hypoxic training seems to be beneficial to enhance hematological parameters, physical performance and cognitive function in older people. The current hypoxic-dose was not able to enhance the serum BDNF-level or V˙O2max.
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Affiliation(s)
- Lutz Schega
- Institute of Sport Science, Otto von Guericke University Magdeburg, Germany
| | - Beate Peter
- Institute of Sport Science, Otto von Guericke University Magdeburg, Germany
| | - Tanja Brigadski
- Institute of Physiology, Otto von Guericke University Magdeburg, Germany; Center of Behavioral Brain Sciences (CBBS), Germany
| | - Volkmar Leßmann
- Institute of Physiology, Otto von Guericke University Magdeburg, Germany; Center of Behavioral Brain Sciences (CBBS), Germany
| | - Berend Isermann
- Institute for Clinical Chemistry and Pathobiochemistry, Otto von Guericke University Magdeburg, Germany
| | - Dennis Hamacher
- Institute of Sport Science, Otto von Guericke University Magdeburg, Germany
| | - Alexander Törpel
- Institute of Sport Science, Otto von Guericke University Magdeburg, Germany.
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Pokrywka A, Zembron-Lacny A, Baldy-Chudzik K, Orysiak J, Sitkowski D, Banach M. The influence of hypoxic physical activity on cfDNA as a new marker of vascular inflammation. Arch Med Sci 2015; 11:1156-63. [PMID: 26788076 PMCID: PMC4697049 DOI: 10.5114/aoms.2015.56341] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 12/12/2014] [Indexed: 02/06/2023] Open
Abstract
The phenomenon of circulating cell-free DNA (cfDNA) is important for many biomedical disciplines including the field of exercise biochemistry and physiology. It is likely that cfDNA is released into the plasma by apoptosis of endothelial cells and circulating endothelial progenitor cells (EPCs), and/or by NETosis of immune cells induced by strenuous exercise. Increases of cfDNA are described to be a potential hallmark for the overtraining syndrome, and might be related to aseptic vascular inflammation in athletes. Yet, the relevance of systemic inflammation and cfDNA with endothelial dysfunction in athletes still remains unclear. In this review article, we provide a current overview of exercise-induced cfDNA release to the circulation with special emphasis on its relationship with apoptosis and NETosis and the effect of hypoxic physical activity on vascular inflammation in athletes.
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Affiliation(s)
- Andrzej Pokrywka
- Department of Applied and Clinical Physiology, University of Zielona Gora, Zielona Gora, Poland
| | - Agnieszka Zembron-Lacny
- Department of Applied and Clinical Physiology, University of Zielona Gora, Zielona Gora, Poland
| | - Katarzyna Baldy-Chudzik
- Department of Molecular Biology of Biological Sciences, University of Zielona Gora, Zielona Gora, Poland
| | - Joanna Orysiak
- Department of Physiological Nutrition, Institute of Sport, Warsaw, Poland
| | | | - Maciej Banach
- Department of Hypertension, Chair of Nephrology and Hypertension, Medical University of Lodz, Lodz, Poland
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Gokyo Khumbu/Ama Dablam Trek 2012: effects of physical training and high-altitude exposure on oxidative metabolism, muscle composition, and metabolic cost of walking in women. Eur J Appl Physiol 2015; 116:129-44. [PMID: 26349745 DOI: 10.1007/s00421-015-3256-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 08/28/2015] [Indexed: 12/13/2022]
Abstract
PURPOSE We investigated the effects of moderate-intensity training at low and high altitude on VO2 and QaO2 kinetics and on myosin heavy-chain expression (MyHC) in seven women (36.3 yy ± 7.1; 65.8 kg ± 11.7; 165 cm ± 8) who participated in two 12- to 14-day trekking expeditions at low (598 m) and high altitude (4132 m) separated by 4 months of recovery. METHODS Breath-by-breath VO2 and beat-by-beat QaO2 at the onset of moderate-intensity cycling exercise and energy cost of walking (Cw) were assessed before and after trekking. MyHC expression of vastus lateralis was evaluated before and after low-altitude and after high-altitude trekking; muscle fiber high-resolution respirography was performed at the beginning of the study and after high-altitude trekking. RESULTS Mean response time of VO2 kinetics was faster (P = 0.002 and P = 0.001) and oxygen deficit was smaller (P = 0.001 and P = 0.0004) after low- and high-altitude trekking, whereas ˙ QaO2 kinetics and Cw did not change. Percentages of slow and fast isoforms of MyHC and mitochondrial mass were not affected by low- and high-altitude training. After training altitude, muscle fiber ADP-stimulated mitochondrial respiration was decreased as compared with the control condition (P = 0.016), whereas leak respiration was increased (P = 0.031), leading to a significant increase in the respiratory control ratio (P = 0.016). CONCLUSIONS Although training did not significantly modify muscle phenotype, it induced beneficial adaptations of the oxygen transport-utilization systems witnessed by faster VO2 kinetics at exercise onset.
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Giordano C, Lemaire C, Li T, Kimoff RJ, Petrof BJ. Autophagy-associated atrophy and metabolic remodeling of the mouse diaphragm after short-term intermittent hypoxia. PLoS One 2015; 10:e0131068. [PMID: 26107816 PMCID: PMC4480857 DOI: 10.1371/journal.pone.0131068] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/28/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Short-term intermittent hypoxia (IH) is common in patients with acute respiratory disorders. Although prolonged exposure to hypoxia induces atrophy and increased fatigability of skeletal muscle, the response to short-term IH is less well known. We hypothesized that the diaphragm and limb muscles would adapt differently to short-term IH given that hypoxia stimulates ventilation and triggers a superimposed exercise stimulus in the diaphragm. METHODS We determined the structural, metabolic, and contractile properties of the mouse diaphragm after 4 days of IH (8 hours per day, 30 episodes per hour to a FiO2 nadir=6%), and compared responses in the diaphragm to a commonly studied reference limb muscle, the tibialis anterior. Outcome measures included muscle fiber size, assays of muscle proteolysis (calpain, ubiquitin-proteasome, and autophagy pathways), markers of oxidative stress and mitochondrial function, quantification of intramyocellular lipid and lipid metabolism genes, type I myosin heavy chain (MyHC) expression, and in vitro contractile properties. RESULTS After 4 days of IH, the diaphragm alone demonstrated significant atrophy (30% decrease of myofiber size) together with increased LC3B-II protein (2.4-fold) and mRNA markers of the autophagy pathway (LC3B, Gabarapl1, Bnip3), whereas active calpain and E3 ubiquitin ligases (MuRF1, atrogin-1) were unaffected in both muscles. Succinate dehydrogenase activity was significantly reduced by IH in both muscles. However, only the diaphragm exhibited increased intramyocellular lipid droplets (2.5-fold) after IH, along with upregulation of genes linked to activated lipid metabolism. In addition, although the diaphragm showed evidence for acute fatigue immediately following IH, it underwent an adaptive fiber type switch toward slow type I MyHC-expressing fibers, associated with greater intrinsic endurance of the muscle during repetitive stimulation in vitro. CONCLUSIONS Short-term IH induces preferential atrophy in the mouse diaphragm together with increased autophagy and a rapid compensatory metabolic adaptation associated with enhanced fatigue resistance.
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Affiliation(s)
- Christian Giordano
- Meakins-Christie Laboratories and Respiratory Division, McGill University, Montreal, Quebec, Canada
- Program for Translational Research in Respiratory Diseases, McGill University Health Centre Research Institute, Montreal, Quebec, Canada
| | - Christian Lemaire
- Meakins-Christie Laboratories and Respiratory Division, McGill University, Montreal, Quebec, Canada
- Program for Translational Research in Respiratory Diseases, McGill University Health Centre Research Institute, Montreal, Quebec, Canada
| | - Tong Li
- Meakins-Christie Laboratories and Respiratory Division, McGill University, Montreal, Quebec, Canada
- Program for Translational Research in Respiratory Diseases, McGill University Health Centre Research Institute, Montreal, Quebec, Canada
| | - R. John Kimoff
- Meakins-Christie Laboratories and Respiratory Division, McGill University, Montreal, Quebec, Canada
- Program for Translational Research in Respiratory Diseases, McGill University Health Centre Research Institute, Montreal, Quebec, Canada
| | - Basil J. Petrof
- Meakins-Christie Laboratories and Respiratory Division, McGill University, Montreal, Quebec, Canada
- Program for Translational Research in Respiratory Diseases, McGill University Health Centre Research Institute, Montreal, Quebec, Canada
- * E-mail:
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Blaauw B, Schiaffino S, Reggiani C. Mechanisms modulating skeletal muscle phenotype. Compr Physiol 2014; 3:1645-87. [PMID: 24265241 DOI: 10.1002/cphy.c130009] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mammalian skeletal muscles are composed of a variety of highly specialized fibers whose selective recruitment allows muscles to fulfill their diverse functional tasks. In addition, skeletal muscle fibers can change their structural and functional properties to perform new tasks or respond to new conditions. The adaptive changes of muscle fibers can occur in response to variations in the pattern of neural stimulation, loading conditions, availability of substrates, and hormonal signals. The new conditions can be detected by multiple sensors, from membrane receptors for hormones and cytokines, to metabolic sensors, which detect high-energy phosphate concentration, oxygen and oxygen free radicals, to calcium binding proteins, which sense variations in intracellular calcium induced by nerve activity, to load sensors located in the sarcomeric and sarcolemmal cytoskeleton. These sensors trigger cascades of signaling pathways which may ultimately lead to changes in fiber size and fiber type. Changes in fiber size reflect an imbalance in protein turnover with either protein accumulation, leading to muscle hypertrophy, or protein loss, with consequent muscle atrophy. Changes in fiber type reflect a reprogramming of gene transcription leading to a remodeling of fiber contractile properties (slow-fast transitions) or metabolic profile (glycolytic-oxidative transitions). While myonuclei are in postmitotic state, satellite cells represent a reserve of new nuclei and can be involved in the adaptive response.
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Affiliation(s)
- Bert Blaauw
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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Dale EA, Ben Mabrouk F, Mitchell GS. Unexpected benefits of intermittent hypoxia: enhanced respiratory and nonrespiratory motor function. Physiology (Bethesda) 2014; 29:39-48. [PMID: 24382870 DOI: 10.1152/physiol.00012.2013] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Intermittent hypoxia (IH) is most often thought of for its role in morbidity associated with sleep-disordered breathing, including central nervous system pathology. However, recent evidence suggests that the nervous system fights back in an attempt to minimize pathology by increasing the expression of growth/trophic factors that confer neuroprotection and neuroplasticity. For example, even modest ("low dose") IH elicits respiratory motor plasticity, increasing the strength of respiratory contractions and breathing. These low IH doses upregulate hypoxia-sensitive growth/trophic factors within respiratory motoneurons but do not elicit detectable pathologies such as hippocampal cell death, neuroinflammation, or systemic hypertension. Recent advances have been made toward understanding cellular mechanisms giving rise to IH-induced respiratory plasticity, and attempts have been made to harness the benefits of low-dose IH to treat respiratory insufficiency after cervical spinal injury. Our recent realization that IH also upregulates growth/trophic factors in nonrespiratory motoneurons and improves limb (or leg) function after incomplete chronic spinal injuries suggests that IH-induced plasticity is a general feature of motor systems. Collectively, available evidence suggests that low-dose IH may represent a safe and effective treatment to restore lost motor function in diverse clinical disorders that impair motor function.
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Affiliation(s)
- E A Dale
- Department of Comparative Biosciences, University of Wisconsin, Madison, Wisconsin
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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.
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Affiliation(s)
- François Billaut
- School of Sport and Exercise Science, Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, VIC, Australia.
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Jacobs RA, Boushel R, Wright-Paradis C, Calbet JAL, Robach P, Gnaiger E, Lundby C. Mitochondrial function in human skeletal muscle following high-altitude exposure. Exp Physiol 2012; 98:245-55. [PMID: 22636256 DOI: 10.1113/expphysiol.2012.066092] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Studies regarding mitochondrial modifications in human skeletal muscle following acclimatization to high altitude are conflicting, and these inconsistencies may be due to the prevalence of representing mitochondrial function through static and isolated measurements of specific mitochondrial characteristics. The aim of this study, therefore, was to investigate mitochondrial function in response to high-altitude acclimatization through measurements of respiratory control in the vastus lateralis muscle. Skeletal muscle biopsies were obtained from 10 lowland natives prior to and again after a total of 9-11 days of exposure to 4559 m. High-resolution respirometry was performed on the muscle samples to compare respiratory chain function and respiratory capacities. Respirometric analysis revealed that mitochondrial function was largely unaffected, because high-altitude exposure did not affect the capacity for fat oxidation or individualized respiration capacity through either complex I or complex II. Respiratory chain function remained unaltered, because neither coupling nor respiratory control changed in response to hypoxic exposure. High-altitude acclimatization did, however, show a tendency (P = 0.059) to limit mass-specific maximal oxidative phosphorylation capacity. These data suggest that 9-11 days of exposure to high altitude do not markedly modify integrated measures of mitochondrial functional capacity in skeletal muscle despite significant decrements in the concentrations of enzymes involved in the tricarboxylic acid cycle and oxidative phosphorylation.
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Affiliation(s)
- Robert A Jacobs
- Zürich Center for Integrative Human Physiology, University of Zurich, Winterthurerstraße 190, 8057 Zürich, Switzerland
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Rebuttal from Millet, Faiss, and Pialoux. J Appl Physiol (1985) 2012; 112:1786-7. [PMID: 22589490 DOI: 10.1152/japplphysiol.00067.2012b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Doria C, Toniolo L, Verratti V, Cancellara P, Pietrangelo T, Marconi V, Paoli A, Pogliaghi S, Fanò G, Reggiani C, Capelli C. Improved V̇O2 uptake kinetics and shift in muscle fiber type in high-altitude trekkers. J Appl Physiol (1985) 2011; 111:1597-605. [PMID: 21868681 DOI: 10.1152/japplphysiol.01439.2010] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The study investigated the effect of prolonged hypoxia on central [i.e., cardiovascular oxygen delivery (Q̇aO2)] and peripheral (i.e., O2 utilization) determinants of oxidative metabolism response during exercise in humans. To this aim, seven male mountaineers were examined before and immediately after the Himalayan Expedition Interamnia 8000–Manaslu 2008, lasting 43 days, among which, 23 days were above 5,000 m. The subjects showed a decrease in body weight ( P < 0.05) and of power output during a Wingate Anaerobic test ( P < 0.05) and an increase of thigh cross-sectional area ( P < 0.05). Absolute maximal O2 uptake (V̇O2max) did not change. The mean response time of V̇O2 kinetics at the onset of step submaximal cycling exercise was reduced significantly from 53.8 s ± 10.9 to 39.8 s ± 10.9 ( P < 0.05), whereas that of Q̇aO2 was not. Analysis of single fibers dissected from vastus lateralis biopsies revealed that the expression of slow isoforms of both heavy and light myosin subunits increased, whereas that of fast isoforms decreased. Unloaded shortening velocity of fibers was decreased significantly. In summary, independent findings converge in indicating that adaptation to chronic hypoxia brings about a fast-to-slow transition of muscle fibers, resulting in a faster activation of the mitochondrial oxidative metabolism. These results indicate that a prolonged and active sojourn in hypoxia may induce muscular ultrastructural and functional changes similar to those observed after aerobic training.
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Affiliation(s)
- C. Doria
- Department of Neurosciences and Imaging, University of Chieti-Pescara, Chieti
| | - L. Toniolo
- Department of Anatomy and Physiology, University of Padova
| | - V. Verratti
- Department of Neurosciences and Imaging, University of Chieti-Pescara, Chieti
| | - P. Cancellara
- Department of Anatomy and Physiology, University of Padova
| | - T. Pietrangelo
- Department of Neurosciences and Imaging, University of Chieti-Pescara, Chieti
| | - V. Marconi
- School of Exercise and Sport Sciences, University of Verona
| | - A. Paoli
- Department of Anatomy and Physiology, University of Padova
| | - S. Pogliaghi
- School of Exercise and Sport Sciences, University of Verona
| | - G. Fanò
- Department of Neurosciences and Imaging, University of Chieti-Pescara, Chieti
| | - C. Reggiani
- Department of Anatomy and Physiology, University of Padova
- CNR, Institute of Neuroscience, Padova; and
| | - C. Capelli
- School of Exercise and Sport Sciences, University of Verona
- CeRiSM, Rovereto, Trento, Italy
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Abstract
It is possible to plan an altitude training (AT) period in such a way that the enhanced physical endurance obtained as a result of adaptation to hypoxia will appear and can be used to improve performance in competition. Yet finding rationales for usage of AT in highly trained swimmers is problematic. In practice AT, in its various forms, is still controversial, and an objective review of research concentrating on the advantages and disadvantages of AT has been presented in several scientific publications, including in no small part the observations of swimmers. The aim of this article is to review the various methods and present both the advantageous and unfavourable physiological changes that occur in athletes as a result of AT. Moreover, AT results in the sport of swimming have been collected. They include an approach towards primary models of altitude/hypoxic training: live high + train high, live high + train low, live low + train high, as well as subsequent methods: Intermittent Hypoxic Exposure (IHE) and Intermittent Hypoxic Training (IHT). Apnoea training, which is descended from freediving, is also mentioned, and which can be used with, or as a substitute for, the well-known IHE or IHT methods. In conclusion, swimmers who train using hypoxia may be among the best-trained athletes, and that even a slight improvement in physical endurance might result in the shortening of a swimming time in a given competition, and the achievement of a personal best, which is hard to obtain by normal training methods, when the personal results of the swimmer have reached a plateau.
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