1
|
Zhao ML, Lu ZJ, Yang L, Ding S, Gao F, Liu YZ, Yang XL, Li X, He SY. The cardiovascular system at high altitude: A bibliometric and visualization analysis. World J Cardiol 2024; 16:199-214. [PMID: 38690218 PMCID: PMC11056872 DOI: 10.4330/wjc.v16.i4.199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/14/2024] [Accepted: 04/01/2024] [Indexed: 04/23/2024] Open
Abstract
BACKGROUND When exposed to high-altitude environments, the cardiovascular system undergoes various changes, the performance and mechanisms of which remain controversial. AIM To summarize the latest research advancements and hot research points in the cardiovascular system at high altitude by conducting a bibliometric and visualization analysis. METHODS The literature was systematically retrieved and filtered using the Web of Science Core Collection of Science Citation Index Expanded. A visualization analysis of the identified publications was conducted employing CiteSpace and VOSviewer. RESULTS A total of 1674 publications were included in the study, with an observed annual increase in the number of publications spanning from 1990 to 2022. The United States of America emerged as the predominant contributor, while Universidad Peruana Cayetano Heredia stood out as the institution with the highest publication output. Notably, Jean-Paul Richalet demonstrated the highest productivity among researchers focusing on the cardiovascular system at high altitude. Furthermore, Peter Bärtsch emerged as the author with the highest number of cited articles. Keyword analysis identified hypoxia, exercise, acclimatization, acute and chronic mountain sickness, pulmonary hypertension, metabolism, and echocardiography as the primary research hot research points and emerging directions in the study of the cardiovascular system at high altitude. CONCLUSION Over the past 32 years, research on the cardiovascular system in high-altitude regions has been steadily increasing. Future research in this field may focus on areas such as hypoxia adaptation, metabolism, and cardiopulmonary exercise. Strengthening interdisciplinary and multi-team collaborations will facilitate further exploration of the pathophysiological mechanisms underlying cardiovascular changes in high-altitude environments and provide a theoretical basis for standardized disease diagnosis and treatment.
Collapse
Affiliation(s)
- Mao-Lin Zhao
- Department of Cardiovascular Surgery, The General Hospital of Western Theater Command, College of Medicine, Southwest Jiaotong University, Chengdu 610083, Sichuan Province, China
| | - Zhong-Jie Lu
- Department of Cardiovascular Surgery, The General Hospital of Western Theater Command, College of Medicine, Southwest Jiaotong University, Chengdu 610083, Sichuan Province, China
| | - Li Yang
- Department of Cardiovascular Surgery, The General Hospital of Western Theater Command, College of Medicine, Southwest Jiaotong University, Chengdu 610083, Sichuan Province, China
| | - Sheng Ding
- Department of Cardiovascular Surgery, The General Hospital of Western Theater Command, College of Medicine, Southwest Jiaotong University, Chengdu 610083, Sichuan Province, China
| | - Feng Gao
- Department of Cardiovascular Surgery, The General Hospital of Western Theater Command, College of Medicine, Southwest Jiaotong University, Chengdu 610083, Sichuan Province, China
| | - Yuan-Zhang Liu
- Department of Cardiovascular Surgery, The General Hospital of Western Theater Command, College of Medicine, Southwest Jiaotong University, Chengdu 610083, Sichuan Province, China
| | - Xue-Lin Yang
- Department of Cardiovascular Surgery, The General Hospital of Western Theater Command, College of Medicine, Southwest Jiaotong University, Chengdu 610083, Sichuan Province, China
| | - Xia Li
- Department of Cardiovascular Surgery, The General Hospital of Western Theater Command, College of Medicine, Southwest Jiaotong University, Chengdu 610083, Sichuan Province, China
| | - Si-Yi He
- Department of Cardiovascular Surgery, The General Hospital of Western Theater Command, Chengdu 610083, Sichuan Province, China.
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Yu Q, Kong Z, Zou L, Chapman R, Shi Q, Nie J. Comparative efficacy of various hypoxic training paradigms on maximal oxygen consumption: A systematic review and network meta-analysis. J Exerc Sci Fit 2023; 21:366-375. [PMID: 37854170 PMCID: PMC10580050 DOI: 10.1016/j.jesf.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 09/09/2023] [Accepted: 09/16/2023] [Indexed: 10/20/2023] Open
Abstract
Background Enhancement in maximal oxygen consumption (VO2max) induced by hypoxic training is important for both athletes and non-athletes. However, the lack of comparison of multiple paradigms and the exploration of related modulating factors leads to the inability to recommend the optimal regimen in different situations. This study aimed to investigate the efficacy of seven common hypoxic training paradigms on VO2max and associated moderators. Methods Electronic (i.e., five databases) and manual searches were performed, and 42 studies involving 1246 healthy adults were included. Pairwise meta-analyses were conducted to compare different hypoxic training paradigms and hypoxic training and control conditions. The Bayesian network meta-analysis model was applied to calculate the standardised mean differences (SMDs) of pre-post VO2max alteration among hypoxic training paradigms in overall, athlete, and non-athlete populations, while meta-regression analyses were employed to explore the relationships between covariates and SMDs. Results All seven hypoxic training paradigms were effective to varying degrees, with SMDs ranging from 1.45 to 7.10. Intermittent hypoxia interval training (IHIT) had the highest probability of being the most efficient hypoxic training paradigm in the overall population and athlete subgroup (42%, 44%), whereas intermittent hypoxic training (IHT) was the most promising hypoxic training paradigm among non-athletes (66%). Meta-regression analysis revealed that saturation hours (coefficient, 0.004; P = 0.038; 95% CI [0.0002, 0.0085]) accounted for variations of VO2max improvement induced by IHT. Conclusion Efficient hypoxic training paradigms for VO2max gains differed between athletes and non-athletes, with IHIT ranking best for athletes and IHT for non-athletes. The practicability of saturation hours is confirmed with respect to dose-response issues in the future hypoxic training and associated scientific research. Registration This study was registered in the PROSPERO international prospective register of systematic reviews (CRD42022333548).
Collapse
Affiliation(s)
- Qian Yu
- Faculty of Education, University of Macau, Macao, China
| | - Zhaowei Kong
- Faculty of Education, University of Macau, Macao, China
| | - Liye Zou
- Exercise Psychophysiology Laboratory, Institute of KEEP Collaborative Innovation, School of Psychology, Shenzhen University, Shenzhen, 518060, China
| | - Robert Chapman
- Department of Kinesiology, School of Public Health, Indiana University, Bloomington, IN, USA
| | - Qingde Shi
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao, China
| | - Jinlei Nie
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao, China
| |
Collapse
|
4
|
Feng X, Zhao L, Chen Y, Wang Z, Lu H, Wang C. Optimal type and dose of hypoxic training for improving maximal aerobic capacity in athletes: a systematic review and Bayesian model-based network meta-analysis. Front Physiol 2023; 14:1223037. [PMID: 37745240 PMCID: PMC10513096 DOI: 10.3389/fphys.2023.1223037] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 08/17/2023] [Indexed: 09/26/2023] Open
Abstract
Objective: This study aimed to compare and rank the effect of hypoxic practices on maximum oxygen consumption (VO2max) in athletes and determine the hypoxic dose-response correlation using network meta-analysis. Methods: The Web of Science, PubMed, EMBASE, and EBSCO databases were systematically search for randomized controlled trials on the effect of hypoxc interventions on the VO2max of athletes published from inception until 21 February 2023. Studies that used live-high train-high (LHTH), live-high train-low (LHTL), live-high, train-high/low (HHL), intermittent hypoxic training (IHT), and intermittent hypoxic exposure (IHE) interventions were primarily included. LHTL was further defined according to the type of hypoxic environment (natural and simulated) and the altitude of the training site (low altitude and sea level). A meta-analysis was conducted to determine the standardized mean difference between the effects of various hypoxic interventions on VO2max and dose-response correlation. Furthermore, the hypoxic dosage of the different interventions were coordinated using the "kilometer hour" model. Results: From 2,072 originally identified titles, 59 studies were finally included in this study. After data pooling, LHTL, LHTH, and IHT outperformed normoxic training in improving the VO2max of athletes. According to the P-scores, LHTL combined with low altitude training was the most effective intervention for improving VO2max (natural: 0.92 and simulated: 0.86) and was better than LHTL combined with sea level training (0.56). A reasonable hypoxic dose range for LHTH (470-1,130 kmh) and HL (500-1,415 kmh) was reported with an inverted U-shaped curve relationship. Conclusion: Different types of hypoxic training compared with normoxic training serve as significant approaches for improving aerobic capacity in athletes. Regardless of the type of hypoxic training and the residential condition, LHTL with low altitude training was the most effective intervention. The characteristics of the dose-effect correlation of LHTH and LHTL may be associated with the negative effects of chronic hypoxia.
Collapse
Affiliation(s)
- Xinmiao Feng
- Sports Coaching College, Beijing Sports University, Beijing, China
| | - Linlin Zhao
- Sports Coaching College, Beijing Sports University, Beijing, China
| | | | - Zihao Wang
- Capital Institute of Physical Education and Sports, Beijing, Beijing, China
| | - Hongyuan Lu
- Sports Coaching College, Beijing Sports University, Beijing, China
| | - Chuangang Wang
- Sports Coaching College, Beijing Sports University, Beijing, China
| |
Collapse
|
5
|
Chen B, Wu Z, Huang X, Li Z, Wu Q, Chen Z. Effect of altitude training on the aerobic capacity of athletes: A systematic review and meta-analysis. Heliyon 2023; 9:e20188. [PMID: 37809554 PMCID: PMC10559955 DOI: 10.1016/j.heliyon.2023.e20188] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 09/12/2023] [Accepted: 09/13/2023] [Indexed: 10/10/2023] Open
Abstract
Purpose With a growing number of athletes and coaches adopting altitude training, the importance for rationalizing and optimizing such training has been emphasized. We conducted a meta-analysis to evaluate the influence of altitude training on athletes' aerobic capacity and to explore the best altitude training method to improve this capacity. Methods We searched Web of Science, SpringerLink, Science Direct, EBSCO, and PubMed databases combined with manual search of the references to collect studies indexed from 1979 to September 2020 on the effect of altitude training on athletes' aerobic capacity. Data from experimental studies that reported hemoglobin levels and maximum oxygen uptake in athletes before and after altitude training, or in athletes performing altitude training in comparison with a control group were analyzed. Data of the populations, intervention, comparison, outcomes and study design were extracted. Review Manager software 5.3 was used for bias evaluation. Results 17 publications were included. In our meta-analysis, altitude training led to higher maximum oxygen uptake [standardized mean difference (SMD) = 0.67, 95% confidence interval (CI) 0.35-1.00, P < 0.001] and hemoglobin level (SMD = 0.50, 95% CI 0.11-0.90, P = 0.013) than training at lower altitude. The result of sensitivity analysis showed that results of meta-analysis were relatively stable, and there was no bias or change in the result of effect size according to the bias test. The results of subgroup analysis showed that high-altitude living and low-altitude training ("Hi-Lo" regime), with a training cycle of about three weeks at an altitude around 2500 m, had better effects than other regimes on the athletes' aerobic capacity. Conclusions Altitude training can improve athletes' aerobic capacity in terms of maximum oxygen uptake and hemoglobin level. Our results are limited by the number and quality of available studies. Therefore, more high-quality studies are needed to verify and extend these findings. Our study can provide scientific suggestions for the training of athletes.
Collapse
Affiliation(s)
- Baoxia Chen
- School of Physical Education, Sichuan University, Chengdu, China
| | - Zhusheng Wu
- School of History and Tourism, Sichuan University, Chengdu, China
| | - Xia Huang
- School of History and Tourism, Sichuan University, Chengdu, China
| | - Zhichao Li
- Human Resources and Social Security Department, Sheyang County, Yancheng, China
| | - Qianjin Wu
- School of Physical Education, Shandong University, Jinan, China
| | - Zichao Chen
- School of Physical Education, Sichuan University, Chengdu, China
| |
Collapse
|
6
|
Liu C, Guo G, Li X, Shen Y, Xu X, Chen Y, Li H, Hao J, He K. Identification of novel urine proteomic biomarkers for high stamina in high-altitude adaptation. Front Physiol 2023; 14:1153166. [PMID: 37250129 PMCID: PMC10214468 DOI: 10.3389/fphys.2023.1153166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 04/21/2023] [Indexed: 05/31/2023] Open
Abstract
Introduction: We aimed to identify urine biomarkers for screening individuals with adaptability to high-altitude hypoxia with high stamina levels. Although most non-high-altitude natives experience rapid decline in physical ability when ascending to high altitudes, some individuals with high-altitude adaptability continue to maintain high endurance levels. Methods: We divided the study population into two groups: the LC group (low change in endurance from low to high altitude) and HC group (high change in endurance from low to high altitude). We performed blood biochemistry testing for individuals at high altitudes and sea level. We used urine peptidome profiling to compare the HH (high-altitude with high stamina) and HL (high-altitude with low stamina) groups and the LC and HC groups to identify urine biomarkers. Results: Routine blood tests revealed that the concentration of white blood cells, lymphocytes and platelets were significantly higher in the HH group than in the HL group. Urine peptidome profiling showed that the proteins ITIH1, PDCD1LG2, NME1-NME2, and CSPG4 were significantly differentially expressed between the HH and HL groups, which was tested using ELISA. Urine proteomic analysis showed that LRG1, NID1, VASN, GPX3, ACP2, and PRSS8 were urine proteomic biomarkers of high stamina during high-altitude adaptation. Conclusion: This study provides a novel approach for identifying potential biomarkers for screening individuals who can adapt to high altitudes with high stamina.
Collapse
Affiliation(s)
- Chunlei Liu
- Translational Medicine Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Ge Guo
- Translational Medicine Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Xin Li
- Translational Medicine Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Yanying Shen
- Translational Medicine Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Xiang Xu
- Translational Medicine Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Yibing Chen
- Translational Medicine Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Hanlu Li
- Translational Medicine Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Jianxiu Hao
- Clinical Sample Bank, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Kunlun He
- Medical Big Data Research Center, Chinese PLA General Hospital, Beijing, China
| |
Collapse
|
7
|
Held S, Rappelt L, Donath L. Acute and Chronic Performance Enhancement in Rowing: A Network Meta-analytical Approach on the Effects of Nutrition and Training. Sports Med 2023; 53:1137-1159. [PMID: 37097415 DOI: 10.1007/s40279-023-01827-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/19/2023] [Indexed: 04/26/2023]
Abstract
INTRODUCTION This systematic review and network meta-analysis assessed via direct and indirect comparison the occurrence and magnitude of effects following different nutritional supplementation strategies and exercise interventions on acute and chronic rowing performance and its surrogates. METHODS PubMed, Web of Science, PsycNET and SPORTDiscus searches were conducted until March 2022 to identify studies that met the following inclusion criteria: (a) controlled trials, (b) rowing performance and its surrogate parameters as outcomes, and (c) peer-reviewed and published in English. Frequentist network meta-analytical approaches were calculated based on standardized mean differences (SMD) using random effects models. RESULTS 71 studies with 1229 healthy rowers (aged 21.5 ± 3.0 years) were included and two main networks (acute and chronic) with each two subnetworks for nutrition and exercise have been created. Both networks revealed low heterogeneity and non-significant inconsistency (I2 ≤ 35.0% and Q statistics: p ≥ 0.12). Based on P-score rankings, while caffeine (P-score 84%; SMD 0.43) revealed relevantly favorable effects in terms of acute rowing performance enhancement, whilst prior weight reduction (P-score 10%; SMD - 0.48) and extensive preload (P-score 18%; SMD - 0.34) impaired acute rowing performance. Chronic blood flow restriction training (P-score 96%; SMD 1.26) and the combination of β-hydroxy-β-methylbutyrate and creatine (P-score 91%; SMD 1.04) induced remarkably large positive effects, while chronic spirulina (P-score 7%; SMD - 1.05) and black currant (P-score 9%; SMD - 0.88) supplementation revealed impairment effects. CONCLUSION Homogeneous and consistent findings from numerous studies indicate that the choice of nutritional supplementation strategy and exercise training regimen are vital for acute and chronic performance enhancement in rowing.
Collapse
Affiliation(s)
- Steffen Held
- Department of Intervention Research in Exercise Training, Institute of Exercise Training and Sport Informatics, German Sport University, Cologne, Germany.
- Department of Sport and Management, IST University of Applied Sciences, Duesseldorf, Germany.
| | - Ludwig Rappelt
- Department of Intervention Research in Exercise Training, Institute of Exercise Training and Sport Informatics, German Sport University, Cologne, Germany
- Department of Movement and Training Science, University of Wuppertal, Wuppertal, Germany
| | - Lars Donath
- Department of Intervention Research in Exercise Training, Institute of Exercise Training and Sport Informatics, German Sport University, Cologne, Germany
| |
Collapse
|
8
|
Westmacott A, Sanal-Hayes NEM, McLaughlin M, Mair JL, Hayes LD. High-Intensity Interval Training (HIIT) in Hypoxia Improves Maximal Aerobic Capacity More Than HIIT in Normoxia: A Systematic Review, Meta-Analysis, and Meta-Regression. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:14261. [PMID: 36361141 PMCID: PMC9658399 DOI: 10.3390/ijerph192114261] [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: 10/03/2022] [Revised: 10/26/2022] [Accepted: 10/27/2022] [Indexed: 06/16/2023]
Abstract
The present study aimed to determine the effect of high intensity interval training (HIIT) in hypoxia on maximal oxygen uptake (VO2max) compared with HIIT in normoxia with a Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)-accordant meta-analysis and meta-regression. Studies which measured VO2max following a minimum of 2 weeks intervention featuring HIIT in hypoxia versus HIIT in normoxia were included. From 119 originally identified titles, nine studies were included (n = 194 participants). Meta-analysis was conducted on change in (∆) VO2max using standardised mean difference (SMD) and a random effects model. Meta-regression examined the relationship between the extent of environmental hypoxia (fractional inspired oxygen [FiO2]) and ∆VO2max and intervention duration and ∆VO2max. The overall SMD for ∆VO2max following HIIT in hypoxia was 1.14 (95% CI = 0.56-1.72; p < 0.001). Meta-regressions identified no significant relationship between FiO2 (coefficient estimate = 0.074, p = 0.852) or intervention duration (coefficient estimate = 0.071, p = 0.423) and ∆VO2max. In conclusion, HIIT in hypoxia improved VO2max compared to HIIT in normoxia. Neither extent of hypoxia, nor training duration modified this effect, however the range in FiO2 was small, which limits interpretation of this meta-regression. Moreover, training duration is not the only training variable known to influence ∆VO2max, and does not appropriately capture total training stress or load. This meta-analysis provides pooled evidence that HIIT in hypoxia may be more efficacious at improving VO2max than HIIT in normoxia. The application of these data suggest adding a hypoxic stimuli to a period of HIIT may be more effective at improving VO2max than HIIT alone. Therefore, coaches and athletes with access to altitude (either natural or simulated) should consider implementing HIIT in hypoxia, rather than HIIT in normoxia where possible, assuming no negative side effects.
Collapse
Affiliation(s)
- Ailsa Westmacott
- Sport and Physical Activity Research Institute, University of the West of Scotland, Glasgow G72 0LH, UK
| | - Nilihan E. M. Sanal-Hayes
- Sport and Physical Activity Research Institute, University of the West of Scotland, Glasgow G72 0LH, UK
| | - Marie McLaughlin
- Sport and Physical Activity Research Institute, University of the West of Scotland, Glasgow G72 0LH, UK
| | - Jacqueline L. Mair
- Future Health Technologies, Singapore-ETH Centre, Campus for Research Excellence and Technological Enterprise, Singapore 138602, Singapore
| | - Lawrence D. Hayes
- Sport and Physical Activity Research Institute, University of the West of Scotland, Glasgow G72 0LH, UK
| |
Collapse
|
9
|
Chen S, Su H, Liu X, Li Q, Yao Y, Cai J, Gao Y, Ma Q, Shi Y. Effects of exercise training in hypoxia versus normoxia on fat-reducing in overweight and/or obese adults: A systematic review and meta-analysis of randomized clinical trials. Front Physiol 2022; 13:940749. [PMID: 36082216 PMCID: PMC9447682 DOI: 10.3389/fphys.2022.940749] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 07/22/2022] [Indexed: 11/17/2022] Open
Abstract
Objective: Fat loss theory under various oxygen conditions has been disputed, and relevant systematic review studies are limited. This study is a systematic review and meta-analysis to assess whether hypoxic exercise training (HET) leads to superior fat-reducing compared with normoxic exercise training (NET). Methods: We searched PubMed, Web of Science, CNKI, ProQuest, Google Scholar, Cochrane Library, and EBSCOhost from inception to June 2022 for articles comparing the effects of hypoxic and normoxic exercise on body composition indicators, glycometabolism, and lipometabolism indicators in obese and overweight adults. Only randomized controlled trials (RCTs) were included. The effect sizes were expressed as standardized mean difference (SMD) and 95% confidence intervals (CI). Between-study heterogeneity was examined using the I2 test and evaluated publication bias via Egger’s regression test. The risk of bias assessment was performed for each included trial using Cochrane Evaluation Tool second generation. The meta-analysis was performed by using R 4.1.3 and RevMan 5.3 analytic tools. Results: A total of 19 RCTs with 444 subjects were analyzed according to the inclusion and exclusion criteria. Among them, there were 14 English literature and five Chinese literature. No significant difference in body composition (SMD -0.10, 95% CI -0.20 to -0.01), glycometabolism and lipid metabolism (SMD -0.01, 95% CI -0.13 to -0.10) has been observed when comparing the HET and NET groups. We only found low heterogeneity among trials assessing glycometabolism and lipometabolism (I2 = 20%, p = 0.09), and no publication bias was detected. Conclusion: The effects of HET and NET on fat loss in overweight or obese people are the same. The application and promotion of HET for fat reduction need further exploration.
Collapse
|
10
|
Hayward GJ, Sims DT, Millet GP, Coquet R, Gaborini L, Schumacher YO, Rhumorbarbe D, Robinson N. The athletic characteristics of Olympic sports to assist anti-doping strategies. Drug Test Anal 2022; 14:1599-1613. [PMID: 35732071 DOI: 10.1002/dta.3329] [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: 01/05/2022] [Revised: 04/06/2022] [Accepted: 05/03/2022] [Indexed: 11/05/2022]
Abstract
The determinants of success in Olympic Games competition are specific to the athletic demands of the sporting event. A global evaluation to quantify the athletic demands across the spectrum of the Olympic Games sport events has not previously been conducted. Thus far, the interpretation and the comparison of sport physiological characteristics within anti-doping organisations (ADOs) risk assessments remains subjective without a standardised framework. Despite its subjective assessment, this information is a key component of any anti-doping programme. Sport characteristics inevitably influence the type of substances and/or methods used for doping purpose and should be captured through a comprehensive analysis. Seven applied sport scientists independently conducted an assessment to quantify the athletic demands across six preselected athletic variables. A Principal Component Analysis was performed on the results of the panel's quantitative assessment for 160 Olympic Sport events. Sport events were clustered using the Hierarchical Density Based Spatial Clustering of Applications with Noise (HDBSCAN) algorithm. The HDBSCAN identified 19 independent cluster groups, 36 sport events remained statistically unassigned to a cluster group representing unique and eventspecific athletic demands. This investigation provides guidance to the anti-doping community to assist in the development of the sport specific physiology component of the risk assessment for Olympic Games disciplines. The dominant athletic characteristics to excel in each of these individual events will highlight areas of how athletes may strive to gain a competitive advantage through doping strategies, and inform the development of an effective and proportionate allocation of testing resources.
Collapse
Affiliation(s)
| | - David T Sims
- Musculoskeletal Science and Sports Medicine, Manchester Metropolitan University, Manchester, United Kingdom
| | - Greǵoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Ronan Coquet
- International Testing Agency, Lausanne, Switzerland
| | | | | | | | | |
Collapse
|
11
|
Rybnikova EA, Nalivaeva NN, Zenko MY, Baranova KA. Intermittent Hypoxic Training as an Effective Tool for Increasing the Adaptive Potential, Endurance and Working Capacity of the Brain. Front Neurosci 2022; 16:941740. [PMID: 35801184 PMCID: PMC9254677 DOI: 10.3389/fnins.2022.941740] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
This review is devoted to the phenomenon of intermittent hypoxic training and is aimed at drawing the attention of researchers to the necessity of studying the mechanisms mediating the positive, particularly neuroprotective, effects of hypoxic training at the molecular level. The review briefly describes the historical aspects of studying the beneficial effects of mild hypoxia, as well as the use of hypoxic training in medicine and sports. The physiological mechanisms of hypoxic adaptation, models of hypoxic training and their effectiveness are summarized, giving examples of their beneficial effects in various organs including the brain. The review emphasizes a high, far from being realized at present, potential of hypoxic training in preventive and clinical medicine especially in the area of neurodegeneration and age-related cognitive decline.
Collapse
Affiliation(s)
- Elena A. Rybnikova
- Pavlov Institute Physiology of Russian Academy of Sciences, St. Petersburg, Russia
- *Correspondence: Elena A. Rybnikova,
| | - Natalia N. Nalivaeva
- Pavlov Institute Physiology of Russian Academy of Sciences, St. Petersburg, Russia
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of Russian Academy of Sciences, St. Petersburg, Russia
| | - Mikhail Y. Zenko
- Pavlov Institute Physiology of Russian Academy of Sciences, St. Petersburg, Russia
| | - Ksenia A. Baranova
- Pavlov Institute Physiology of Russian Academy of Sciences, St. Petersburg, Russia
| |
Collapse
|
12
|
Acute Physiological Response to Different Sprint Training Protocols in Normobaric Hypoxia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19052607. [PMID: 35270299 PMCID: PMC8909614 DOI: 10.3390/ijerph19052607] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/14/2022] [Accepted: 02/21/2022] [Indexed: 11/17/2022]
Abstract
BACKGROUND the purpose of this study was to examine acute physiological responses to and the performance effects of two sprint training protocols in normobaric hypoxic conditions. METHODS Healthy competitive female (n = 2) and male (n = 5) kayakers (19 ± 2.1 years) performed four sprint training sessions on a kayak ergometer over a period of two weeks. Participants performed five sets of 12 × 5 s sprints or 3 × 20 s sprints in both normobaric normoxic (NOR, FiO2 = 20.9%) or normobaric hypoxic (HYP, FiO2 = 13.6%) conditions. The peak power output (PPO), rate of perceived exertion (RPE), and heart rate (HR) of each participant were monitored continuously. Their blood lactate concentrations ([BLa+]), in addition to their blood gas (mixed-venous partial pressure (p) of carbon dioxide (pCO2), O2 (pO2), and oxygen saturations (sO2)) were collected before and after exercise. RESULTS A significantly greater RPE, HR, and [BLa+] response and a significant decrease in pCO2, pO2, and sO2 were observed in HYP conditions versus NOR ones, independent of the type of training session. The PPO of participants did not differ between sessions. Their RPE in HYP12 × 5 was greater compared to all other sessions. CONCLUSIONS The HYP conditions elicited significantly greater physiological strain compared to NOR conditions and this was similar in both training sessions. Our results suggest that either sprint training protocol in HYP conditions may induce more positive training adaptations compared to sprint training in NOR conditions.
Collapse
|
13
|
[Into thin air - Altitude training and hypoxic conditioning: From athlete to patient]. Rev Mal Respir 2021; 38:404-417. [PMID: 33722445 DOI: 10.1016/j.rmr.2021.02.066] [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: 07/12/2019] [Accepted: 10/15/2020] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Hypoxic exposure should be considered as a continuum, the effects of which depend on the dose and individual response to hypoxia. Hypoxic conditioning (HC) represents an innovative and promising strategy, ranging from improved human performance to therapeutic applications. STATE OF THE ART With the aim of improving sports performance, the effectiveness of hypoxic exposure, whether natural or simulated, is difficult to demonstrate because of the large variability of the protocols used. In therapeutics, the benefits of HC are described in many pathological conditions such as obesity or cardiovascular pathologies. If the HC benefits from a strong preclinical rationale, its application to humans remains limited. PERSPECTIVES Advances in training and acclimation will require greater personalization and precise periodization of hypoxic exposures. For patients, the harmonization of HC protocols, the identification of biomarkers and the development and subsequent validation of devices allowing a precise control of the hypoxic stimulus are necessary steps for the development of HC. CONCLUSIONS From the athlete to the patient, HC represents an innovative and promising field of research, ranging from the improvement of human performance to the prevention and treatment of certain pathologies.
Collapse
|
14
|
Shah N, Bye K, Marshall A, Woods DR, O'Hara J, Barlow M, Rimmer J, Boos CJ. The Effects of Apnea Training, Using Voluntary Breath Holds, on High Altitude Acclimation: Breathe-High Altitude Study. High Alt Med Biol 2020; 21:152-159. [DOI: 10.1089/ham.2019.0087] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- Nishma Shah
- Department of Surgical Sciences, Institute of Sports and Exercise Health, University College, London, United Kingdom
| | - Kyo Bye
- Defence Medical Services, Lichfield, United Kingdom
| | - Anna Marshall
- Department of Surgical Sciences, Institute of Sports and Exercise Health, University College, London, United Kingdom
| | - David R. Woods
- Defence Medical Services, Lichfield, United Kingdom
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom
- Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, United Kingdom
| | - John O'Hara
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom
| | - Matthew Barlow
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom
| | - Jo Rimmer
- Defence Medical Services, Lichfield, United Kingdom
| | - Christopher John Boos
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom
- Department of Cardiology, Poole Hospital NHS Foundation Trust, Poole, United Kingdom
- Department of Postgraduate Medical Education, Bournemouth University, Bournemouth, United Kingdom
| |
Collapse
|
15
|
Mujika I, Sharma AP, Stellingwerff T. Contemporary Periodization of Altitude Training for Elite Endurance Athletes: A Narrative Review. Sports Med 2020; 49:1651-1669. [PMID: 31452130 DOI: 10.1007/s40279-019-01165-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Since the 1960s there has been an escalation in the purposeful utilization of altitude to enhance endurance athletic performance. This has been mirrored by a parallel intensification in research pursuits to elucidate hypoxia-induced adaptive mechanisms and substantiate optimal altitude protocols (e.g., hypoxic dose, duration, timing, and confounding factors such as training load periodization, health status, individual response, and nutritional considerations). The majority of the research and the field-based rationale for altitude has focused on hematological outcomes, where hypoxia causes an increased erythropoietic response resulting in augmented hemoglobin mass. Hypoxia-induced non-hematological adaptations, such as mitochondrial gene expression and enhanced muscle buffering capacity may also impact athletic performance, but research in elite endurance athletes is limited. However, despite significant scientific progress in our understanding of hypobaric hypoxia (natural altitude) and normobaric hypoxia (simulated altitude), elite endurance athletes and coaches still tend to be trailblazers at the coal face of cutting-edge altitude application to optimize individual performance, and they already implement novel altitude training interventions and progressive periodization and monitoring approaches. Published and field-based data strongly suggest that altitude training in elite endurance athletes should follow a long- and short-term periodized approach, integrating exercise training and recovery manipulation, performance peaking, adaptation monitoring, nutritional approaches, and the use of normobaric hypoxia in conjunction with terrestrial altitude. Future research should focus on the long-term effects of accumulated altitude training through repeated exposures, the interactions between altitude and other components of a periodized approach to elite athletic preparation, and the time course of non-hematological hypoxic adaptation and de-adaptation, and the potential differences in exercise-induced altitude adaptations between different modes of exercise.
Collapse
Affiliation(s)
- Iñigo Mujika
- Department of Physiology, Faculty of Medicine and Odontology, University of the Basque Country, Leioa, Basque Country, Spain. .,Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Universidad Finis Terrae, Santiago, Chile.
| | - Avish P Sharma
- Griffith Sports Physiology and Performance, School of Allied Health Sciences, Griffith University, Gold Coast, QLD, Australia.,Triathlon Australia, Burleigh Heads, QLD, Australia
| | - Trent Stellingwerff
- Canadian Sport Institute-Pacific, Victoria, BC, Canada.,Department of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada
| |
Collapse
|
16
|
Hematological status and endurance performance predictors after low altitude training supported by normobaric hypoxia: a double-blind, placebo controlled study. Biol Sport 2020; 36:341-349. [PMID: 31938005 PMCID: PMC6945048 DOI: 10.5114/biolsport.2019.88760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 07/04/2019] [Accepted: 09/25/2019] [Indexed: 11/20/2022] Open
Abstract
The benefits of altitude/hypoxic training for sea level performance are still under debate. This study examined the effects of low altitude training supported by normobaric hypoxia on hematological status and endurance performance predictors in elite female cyclists. Twenty-two female cyclists trained for 3 weeks at low altitude (<1100 m) and 2 weeks near sea level. During the first 3 weeks, 15 subjects stayed in hypoxic rooms simulating an altitude of 2200 m (+NH group, n = 8) or 1000 m (placebo group, n = 7), and 7 (control group) stayed in regular rooms. Significant increases in total hemoglobin mass (tHb-mass: p = 0.008, p = 0.025), power at 4 mmol·l-1 lactate (PAT4: p = 0.004, p = 0.005) (in absolute and relative values, respectively) and maximal power (PF: p = 0.034) (in absolute values) were observed. However, these effects were not associated with normobaric hypoxia. Changes in tHb-mass were not associated with initial concentrations of ferritin or transferrin receptor, whereas changes in relative tHb-mass (r = -0.53, p = 0.012), PF (r = -0.53, p = 0.01) and PAT4 (r = -0.65, p = 0.001) were inversely correlated with initial values. Changes in tHb-mass and PAT4 were positively correlated (r = 0.50, p = 0.017; r = 0.47, p = 0.028). Regardless of normobaric hypoxia application, low altitude training followed by sea-level training might improve hematological status in elite female cyclists, especially with relatively low initial values of tHb-mass, which could translate into enhanced endurance performance.
Collapse
|
17
|
Faulhaber M, Pramsohler S, Rausch L, Menz V. Cardiorespiratory and Metabolic Responses During Graded Exercise in Normobaric and Hypobaric Hypoxia. High Alt Med Biol 2020; 21:70-75. [PMID: 31923367 DOI: 10.1089/ham.2019.0094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: The study investigated submaximal exercise responses during an acute exposure to normobaric hypoxia (NH) versus hypobaric hypoxia (HH) focusing on different exercise intensities. Methods: Eight recreationally trained male subjects (age 23 ± 3 years) performed submaximal cycling exercise at three different intensity levels (100, 150, and 200 W) in NH (simulated altitude 3150 m) and HH (terrestrial high altitude, 3150 m) in a cross-over study design. Cardiorespiratory parameter, blood lactate concentration, and ratings of perceived exertion were determined at each intensity level. Results: Cardiorespiratory parameters, arterial oxygen saturation, and ratings of perceived exertion did not differ between NH and HH except for the higher ventilatory equivalent for oxygen in HH compared to NH (25.9 ± 1.3 vs. 24.6 ± 1.0 at 100 W, 28.0 ± 1.6 vs. 27.1 ± 1.6 at 150 W, 32.1 ± 3.9 vs. 31.3 ± 3.6 at 200 W, p = 0.03). Blood lactate concentration tended to be higher in HH compared to NH (1.8 ± 0.9 mmol/L vs. 1.7 ± 0.8 mmol/L at 100 W, 3.2 ± 1.8 mmol/L vs. 2.8 ± 1.6 mmol/L at 150 W, 6.0 ± 3.1 mmol/L vs. 5.5 ± 3.0 mmol/L at 200 W, p = 0.08) with a significant interaction effect for exercise intensity (p = 0.02). Conclusions: Cycling during acute exposure to NH appears to result in equivalent cardiorespiratory responses to HH. The more pronounced lactate accumulation in HH should be a topic of future research.
Collapse
Affiliation(s)
- Martin Faulhaber
- Department of Sport Science, University Innsbruck, Innsbruck, Austria.,Austrian Society of Alpine and High Altitude Medicine, Mieming, Austria
| | - Stephan Pramsohler
- Hermann Buhl Institute for Hypoxia and Sleep Medicine Research, Bad Aibling, Germany
| | - Linda Rausch
- Hermann Buhl Institute for Hypoxia and Sleep Medicine Research, Bad Aibling, Germany
| | - Verena Menz
- Department of Sport Science, University Innsbruck, Innsbruck, Austria
| |
Collapse
|
18
|
Hypoxia and exercise interactions on skeletal muscle insulin sensitivity in obese subjects with metabolic syndrome: results of a randomized controlled trial. Int J Obes (Lond) 2019; 44:1119-1128. [PMID: 31819201 DOI: 10.1038/s41366-019-0504-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 10/28/2019] [Accepted: 11/19/2019] [Indexed: 11/08/2022]
Abstract
BACKGROUND Physical activity improves insulin sensitivity in obesity. Hypoxia training is claimed to augment this effect. We tested the hypothesis that normobaric hypoxia training would improve insulin sensitivity in obese patients with metabolic syndrome. METHODS In a randomized controlled trial, 23 obese men with metabolic syndrome who were not informed of the FiO2 conditions underwent a 6-week physical exercise intervention under ambient (n = 11; FiO2 21%) conditions or hypoxia (n = 12; FiO2 15%) using a normobaric hypoxic chamber. Three 60-min sessions of interval training were performed each week at 60% of individual V̇O2max. Assessment of myocellular insulin sensitivity by euglycemic hyperinsulinemic clamp was performed in 21 of these subjects before and after 6 weeks of training. Comprehensive phenotyping also included biopsies of subcutaneous adipose tissues. RESULTS The intermittent moderate physical exercise protocol did not substantially change the myocellular insulin sensitivity within 6 weeks under normoxic conditions (ISIClamp: 0.035 (IQR 0.016-0.075) vs. 0.037 (IQR 0.026-0.056) mg* kg-1 *min-1/(mU* l-1); p = 0.767). In contrast, ISIClamp improved during hypoxia training (0.028 (IQR 0.018-0.035) vs. 0.038 (IQR 0.024-0.060) mg * kg-1 *min-1/(mU *l-1); p < 0.05). Between group comparison of ISIClamp change revealed a small difference between groups (Cohen's d = 0.26). Within the hypoxic group, improvement of ISIClamp during training was associated with individual increase of circulating vascular endothelial growth factor (VEGF) levels (r = 0.678, p = 0.015), even if mean VEGF levels were not modified by any training condition. Atrial natriuretic peptide (ANP) system components were not associated with increased ISIClamp during hypoxic training. CONCLUSIONS Physical training under hypoxic conditions could partially augment the favorable effects of exercise alone on myocellular insulin sensitivity in obese men with metabolic syndrome. Concomitant changes in VEGF might represent an underlying pathophysiological mechanism.
Collapse
|
19
|
Yamaguchi K, Kasai N, Sumi D, Yatsutani H, Girard O, Goto K. Muscle Oxygenation During Repeated Double-Poling Sprint Exercise in Normobaric Hypoxia and Normoxia. Front Physiol 2019; 10:743. [PMID: 31275162 PMCID: PMC6591374 DOI: 10.3389/fphys.2019.00743] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/29/2019] [Indexed: 12/16/2022] Open
Abstract
We compared upper limb muscle oxygenation responses during repeated double-poling sprint exercise in normobaric hypoxia and normoxia. Eight male kayakers completed a repeated double-poling sprint exercise (3 × 3 × 20-s maximal sprints, 40-s passive recovery, 5-min rest) in either hypoxia (HYP, FiO2 = 14.5%) or normoxia (NOR, FiO2 = 20.9%). Power output, muscle oxygenation of triceps brachii muscle (using near infrared spectroscopy), arterial oxygen saturation, and cardiorespiratory variables were monitored. Mean power output tended to be lower (-5.2%; P = 0.06) in HYP compared with NOR, while arterial oxygen saturation (82.9 ± 0.9% vs. 90.5 ± 0.8%) and systemic oxygen uptake (1936 ± 140 vs. 2408 ± 83 mL⋅min-1) values were lower (P < 0.05). Exercise-induced increases in deoxygenated hemoglobin (241.7 ± 46.9% vs. 175.8 ± 27.2%) and total hemoglobin (138.0 ± 18.1% vs. 112.1 ± 6.7%) were greater in HYP in reference to NOR (P < 0.05). Despite moderate hypoxia exacerbating exercise-induced elevation in blood perfusion of active upper limb musculature, power output during repeated double-poling exercise only tended to be lower.
Collapse
Affiliation(s)
- Keiichi Yamaguchi
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Nobukazu Kasai
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Daichi Sumi
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Haruka Yatsutani
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Olivier Girard
- Murdoch Applied Sports Science (MASS) Laboratory, Murdoch University, Perth, WA, Australia
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| |
Collapse
|
20
|
Intermittent normobaric hypoxia facilitates high altitude acclimatization by curtailing hypoxia-induced inflammation and dyslipidemia. Pflugers Arch 2019; 471:949-959. [DOI: 10.1007/s00424-019-02273-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/26/2019] [Accepted: 03/20/2019] [Indexed: 12/23/2022]
|
21
|
Enhancing cardiac vagal activity: Factors of interest for sport psychology. PROGRESS IN BRAIN RESEARCH 2018; 240:71-92. [PMID: 30390842 DOI: 10.1016/bs.pbr.2018.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Self-regulation plays a critical role in sport performance. An objective, psychophysiological marker of self-regulation is cardiac vagal activity, the activity of the vagus nerve regulating cardiac functioning. The aim of this paper is to provide an overview of factors influencing cardiac vagal activity, which can be useful for athletes. Specifically, we organize this overview in two main domains: personal factors and environmental factors. Among the personal factors, we discuss the behavioral strategies that can be used by athletes: nutrition, non-ingestive oral habits, water immersion, body temperature reduction, sleeping habits, relaxation methods, cognitive techniques, praying, music, and exercise. Among environmental factors, we discuss those linked to the social (i.e., contact with humans and animals) and physical (i.e., aromas, lights, sounds, temperature, outdoor, altitude) environment. Future research directions are given, as well as practical implications for athletes and coaches.
Collapse
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
Viscor G, Torrella JR, Corral L, Ricart A, Javierre C, Pages T, Ventura JL. Physiological and Biological Responses to Short-Term Intermittent Hypobaric Hypoxia Exposure: From Sports and Mountain Medicine to New Biomedical Applications. Front Physiol 2018; 9:814. [PMID: 30038574 PMCID: PMC6046402 DOI: 10.3389/fphys.2018.00814] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/11/2018] [Indexed: 12/14/2022] Open
Abstract
In recent years, the altitude acclimatization responses elicited by short-term intermittent exposure to hypoxia have been subject to renewed attention. The main goal of short-term intermittent hypobaric hypoxia exposure programs was originally to improve the aerobic capacity of athletes or to accelerate the altitude acclimatization response in alpinists, since such programs induce an increase in erythrocyte mass. Several model programs of intermittent exposure to hypoxia have presented efficiency with respect to this goal, without any of the inconveniences or negative consequences associated with permanent stays at moderate or high altitudes. Artificial intermittent exposure to normobaric hypoxia systems have seen a rapid rise in popularity among recreational and professional athletes, not only due to their unbeatable cost/efficiency ratio, but also because they help prevent common inconveniences associated with high-altitude stays such as social isolation, nutritional limitations, and other minor health and comfort-related annoyances. Today, intermittent exposure to hypobaric hypoxia is known to elicit other physiological response types in several organs and body systems. These responses range from alterations in the ventilatory pattern to modulation of the mitochondrial function. The central role played by hypoxia-inducible factor (HIF) in activating a signaling molecular cascade after hypoxia exposure is well known. Among these targets, several growth factors that upregulate the capillary bed by inducing angiogenesis and promoting oxidative metabolism merit special attention. Applying intermittent hypobaric hypoxia to promote the action of some molecules, such as angiogenic factors, could improve repair and recovery in many tissue types. This article uses a comprehensive approach to examine data obtained in recent years. We consider evidence collected from different tissues, including myocardial capillarization, skeletal muscle fiber types and fiber size changes induced by intermittent hypoxia exposure, and discuss the evidence that points to beneficial interventions in applied fields such as sport science. Short-term intermittent hypoxia may not only be useful for healthy people, but could also be considered a promising tool to be applied, with due caution, to some pathophysiological states.
Collapse
Affiliation(s)
- Ginés Viscor
- Physiology Section, Department of Cell Biology, Physiology and Immunology, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Joan R. Torrella
- Physiology Section, Department of Cell Biology, Physiology and Immunology, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Luisa Corral
- Exercise Physiology Unit, Department of Physiological Sciences, Faculty of Medicine and Health Sciences, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Antoni Ricart
- Exercise Physiology Unit, Department of Physiological Sciences, Faculty of Medicine and Health Sciences, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Casimiro Javierre
- Exercise Physiology Unit, Department of Physiological Sciences, Faculty of Medicine and Health Sciences, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Teresa Pages
- Physiology Section, Department of Cell Biology, Physiology and Immunology, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Josep L. Ventura
- Exercise Physiology Unit, Department of Physiological Sciences, Faculty of Medicine and Health Sciences, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| |
Collapse
|
24
|
Koivisto AE, Paulsen G, Paur I, Garthe I, Tønnessen E, Raastad T, Bastani NE, Hallén J, Blomhoff R, Bøhn SK. Antioxidant-rich foods and response to altitude training: A randomized controlled trial in elite endurance athletes. Scand J Med Sci Sports 2018; 28:1982-1995. [PMID: 29749641 DOI: 10.1111/sms.13212] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2018] [Indexed: 01/04/2023]
Abstract
High doses of isolated antioxidant supplements such as vitamin C and E have demonstrated the potential to blunt cellular adaptations to training. It is, however, unknown whether intake of high doses of antioxidants from foods has similar effects. Hence, the aim of the study was to investigate whether intake of antioxidant-rich foods affects adaptations to altitude training in elite athletes. In a randomized controlled trial, 31 national team endurance athletes (23 ± 5 years) ingested antioxidant-rich foods (n = 16) or eucaloric control foods (n = 15) daily during a 3-week altitude training camp (2320 m). Changes from baseline to post-altitude in hemoglobin mass (Hbmass ; optimized CO rebreathing), maximal oxygen uptake (VO2max ; n = 16) or 100 m swimming performance (n = 10), and blood parameters were compared between the groups. The antioxidant group significantly increased total intake of antioxidant-rich foods (~118%) compared to the control group during the intervention. The total study population improved VO2max by 2.5% (1.7 mL/kg/min, P = .006) and Hbmass by 4.7% (48 g, P < .001), but not 100 m swimming performance. No difference was found between the groups regarding changes in Hbmass , VO2max or swimming performance. However, hemoglobin concentration increased more in the antioxidant group (effect size = 0.7; P = .045) with a concomitantly larger decrease in plasma and blood volumes compared to control group. Changes in ferritin and erythropoietin from pre- to post-altitude did not differ between the groups. Doubling the intake of antioxidant-rich foods was well tolerated and did not negatively influence the adaptive response to altitude training in elite endurance athletes.
Collapse
Affiliation(s)
| | - G Paulsen
- Norwegian Olympic Sports Centre, Oslo, Norway.,Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - I Paur
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Division of Cancer Medicine, Oslo University Hospital, Oslo, Norway
| | - I Garthe
- Norwegian Olympic Sports Centre, Oslo, Norway
| | - E Tønnessen
- Norwegian Olympic Sports Centre, Oslo, Norway
| | - T Raastad
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - N E Bastani
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - J Hallén
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - R Blomhoff
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Division of Cancer Medicine, Oslo University Hospital, Oslo, Norway
| | - S K Bøhn
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| |
Collapse
|