Mechanical alterations during interval-training treadmill runs in high-level male team-sport players

Girard, O., Brocherie, F., Morin, J-B and Millet, G.P. (2017) Mechanical alterations during interval-training treadmill runs in high-level male team-sport players. Journal of Science and Medicine in Sport, 20 (1). pp. 87-91.

Abstract

Objectives
To examine mechanical alterations during interval-training treadmill runs in high-level team-sport players.

Design
Within-participants repeated measures.

Methods
Twenty high-level male field-hockey players performed six 30-s runs at 5.53 ± 0.19 m s−1 corresponding to 115% of their velocity associated with maximal oxygen uptake (vVO2max) with 30-s passive recovery on an instrumented treadmill. Continuous measurement of running kinetics/kinematics and spring-mass characteristics were performed and values were subsequently averaged over 20 s (8th–28th s) for comparison.

Results
Contact time (+1.1 ± 4.3%; p = 0.044), aerial time (+4.1 ± 5.3%; p = 0.001), step length (+2.4 ± 2.2%; p < 0.001) along with mean loading rates (+7.1 ± 10.6%; p = 0.026) increased from the first to the last interval, whereas step frequency (−2.3 ± 2.1%; p < 0.001) decreased. Both centre of mass vertical displacement (+3.0 ± 6.0%; p < 0.001) and leg compression (+2.8 ± 9.7%; p = 0.036), but not peak vertical forces (0.0 ± 4.1%; p = 0.761), increased with fatigue. Vertical stiffness decreased (−2.8 ± 6.9%; p = 0.012), whereas leg stiffness did not change across intervals (p = 0.149).

Conclusions
During interval-training treadmill runs, high-level team-sport players modified their mechanical behaviour towards lower vertical stiffness while preserving a constant leg stiffness. Maintenance of running velocity induced longer step lengths and decreased step frequencies that were also accompanied by increased impact loading rates. These mechanical alterations occurred early during the set.

Item Type:	Journal Article
Publisher:	Elsevier BV
Copyright:	© 2016 Sports Medicine Australia.
URI:	http://researchrepository.murdoch.edu.au/id/eprint/45558

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