Chris Chow Li Tee, Mee Chee Chong, Viswanath Sundar, Chuen Leang Chok, Mohd Rizal Md Razali, Wee Kian Yeo, Olivier Girard
{"title":"Influence of exercise intensity and hypoxic exposure on physiological, perceptual and biomechanical responses to treadmill running","authors":"Chris Chow Li Tee, Mee Chee Chong, Viswanath Sundar, Chuen Leang Chok, Mohd Rizal Md Razali, Wee Kian Yeo, Olivier Girard","doi":"10.1080/17461391.2022.2109066","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>Acute physiological, perceptual and biomechanical consequences of manipulating both exercise intensity and hypoxic exposure during treadmill running were determined. On separate days, eleven trained individuals ran for 45 s (separated by 135 s of rest) on an instrumented treadmill at seven running speeds (8, 10, 12, 14, 16, 18 and 20 km.h<sup>−1</sup>) in normoxia (NM, FiO<sub>2</sub> = 20.9%), moderate hypoxia (MH, FiO<sub>2</sub> = 16.1%), high hypoxia (HH, FiO<sub>2</sub> = 14.1%) and severe hypoxia (SH, FiO<sub>2</sub> = 13.0%). Running mechanics were collected over 20 consecutive steps (i.e. after running ∼25 s), with concurrent assessment of physiological (heart rate and arterial oxygen saturation) and perceptual (overall perceived discomfort, difficulty breathing and leg discomfort) responses. Two-way repeated-measures ANOVA (seven speeds × four conditions) were used. There was a speed × condition interaction for heart rate (<i>p</i> = 0.045, ηp<sup>2 </sup>=<sup> </sup>0.22), with lower values in NM, MH and HH compared to SH at 8 km.h<sup>−1</sup> (125 ± 12, 125 ± 11, 128 ± 12 vs 132 ± 10 b.min<sup>−1</sup>). Overall perceived discomfort (8 and 16 km.h<sup>−1</sup>; <i>p</i> = 0.019 and <i>p</i> = 0.007, ηp<sup>2 </sup>= 0.21, respectively) and perceived difficulty breathing (all speeds; <i>p</i> = 0.023, ηp<sup>2 </sup>= 0.37) were greater in SH compared to MH, whereas leg discomfort was not influenced by hypoxic exposure. Minimal difference was observed in the twelve kinetics/kinematics variables with hypoxia (<i>p</i> > 0.122; η<sub>p</sub><sup>2 </sup>= 0.19). Running at slower speeds in combination with severe hypoxia elevates physiological and perceptual responses without a corresponding increase in ground reaction forces.</p>\n </div>","PeriodicalId":93999,"journal":{"name":"European journal of sport science","volume":"23 8","pages":"1581-1590"},"PeriodicalIF":0.0000,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1080/17461391.2022.2109066","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European journal of sport science","FirstCategoryId":"1085","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1080/17461391.2022.2109066","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Acute physiological, perceptual and biomechanical consequences of manipulating both exercise intensity and hypoxic exposure during treadmill running were determined. On separate days, eleven trained individuals ran for 45 s (separated by 135 s of rest) on an instrumented treadmill at seven running speeds (8, 10, 12, 14, 16, 18 and 20 km.h−1) in normoxia (NM, FiO2 = 20.9%), moderate hypoxia (MH, FiO2 = 16.1%), high hypoxia (HH, FiO2 = 14.1%) and severe hypoxia (SH, FiO2 = 13.0%). Running mechanics were collected over 20 consecutive steps (i.e. after running ∼25 s), with concurrent assessment of physiological (heart rate and arterial oxygen saturation) and perceptual (overall perceived discomfort, difficulty breathing and leg discomfort) responses. Two-way repeated-measures ANOVA (seven speeds × four conditions) were used. There was a speed × condition interaction for heart rate (p = 0.045, ηp2 =0.22), with lower values in NM, MH and HH compared to SH at 8 km.h−1 (125 ± 12, 125 ± 11, 128 ± 12 vs 132 ± 10 b.min−1). Overall perceived discomfort (8 and 16 km.h−1; p = 0.019 and p = 0.007, ηp2 = 0.21, respectively) and perceived difficulty breathing (all speeds; p = 0.023, ηp2 = 0.37) were greater in SH compared to MH, whereas leg discomfort was not influenced by hypoxic exposure. Minimal difference was observed in the twelve kinetics/kinematics variables with hypoxia (p > 0.122; ηp2 = 0.19). Running at slower speeds in combination with severe hypoxia elevates physiological and perceptual responses without a corresponding increase in ground reaction forces.