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AuthorMtibaa K.
AuthorZarrouk N.
AuthorGirard O.
AuthorRyu J.H.
AuthorHautier C.
AuthorRacinais S.
Available date2020-04-01T06:59:41Z
Publication Date2019
Publication NameJournal of Science and Medicine in Sport
ResourceScopus
ISSN14402440
URIhttp://dx.doi.org/10.1016/j.jsams.2019.07.008
URIhttp://hdl.handle.net/10576/13662
AbstractObjectives To determine the effects of heat stress on ankle proprioception and running gait pattern. Design Counterbalanced repeated measures. Methods 12 trained runners performed a proprioception test (active movement discrimination) before and immediately after a 30 min, self-paced treadmill run in HOT (39 °C) and COOL (22 °C) ambient conditions. Velocity was imposed during the first and last minute (70% of maximal aerobic velocity, 13.3 ± 0.8 km h−1) for determination of running mechanics and spring–mass characteristics. Results Rectal (39.7 ± 0.4 vs. 39.4 ± 0.4 °C), skin (36.3 ± 1.1 vs. 31.8 ± 1.1 °C) and average body (38.3 ± 0.2 vs. 36.4 ± 0.4 °C) temperatures together with heart rate (178 ± 8 vs. 174 ± 6 bpm) and thermal discomfort (6.5 ± 0.5 vs. 4.3 ± 1.3) were all higher at the end of the HOT compared to COOL run (all p < 0.05). Distance covered was lower in HOT than COOL (−5.1 ± 3.6%, p < 0.001). Average error during the proprioception test increased after running in HOT (+11%, p < 0.05) but not in COOL (−2%). There was no significant difference for most segmental and joint angles at heel contact, except for a global increase in pelvis retroversion and decrease in ankle dorsi-flexion angles with time (p < 0.05). Step frequency decreased (−2.5 ± 3.6%) and step length increased (+2.6 ± 3.8%) over time (p < 0.05), independently of condition. Spring–mass characteristics remained unchanged (all p > 0.05). Conclusions Heat stress exacerbates thermal, cardiovascular and perceptual responses, while running velocity was slower during a 30 min self-paced treadmill run. Heat stress also impairs ankle proprioception during an active movement discrimination task, but it has no influence on gait pattern assessed at a constant, sub-maximal velocity.
SponsorThe authors thank Clint Hansen for his methodological input. The authors thank Mohammed Aziz Farooq for his support with the statistical analysis. The authors thank the participants for their involvement. The results of this study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. This study was internally funded by Aspetar Orthopedic and Sports Medicine Hospital . This project was conducted using an instrumented treadmill that was funded by QNRF (NPRP 4-760-3-217).
Languageen
PublisherElsevier Ltd
SubjectHyperthermia
Kinematics
Kinetics
Self-paced exercise
Sense of position
TitleHeat stress impairs proprioception but not running mechanics
TypeArticle
Pagination1361-1366
Issue Number12
Volume Number22
dc.accessType Abstract Only


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