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Effect of two maximal isometric contractions on eccentric exercise-induced muscle damage of the elbow flexors

journal contribution
posted on 2013-06-01, 00:00 authored by T C Chen, H-L Chen, M-J Lin, C-H Chen, Alan Pearce, K Nosaka
This study investigated the time wise protective effect conferred by two maximal voluntary isometric contractions (2MVCs) at 20° elbow flexion on muscle damage induced by 30 maximal isokinetic (60° s(-1)) eccentric contractions of the elbow flexors (MaxECC). Sixty-five young untrained men were randomly assigned to a control group that did not perform 2MVCs, or one of four experimental groups (n = 13 per group) who performed 2MVCs either immediately (0d), 2 (2d), 4 (4d) or 7 days (7d) before MaxECC. Changes in maximal isokinetic (60° s(-1)) concentric torque (MVC-CON), optimum angle (OA), range of motion, upper arm circumference, muscle soreness, plasma creatine kinase activity and myoglobin concentration, and ultrasound echo-intensity following MaxECC were compared among the groups by a two-way repeated measures ANOVA. No significant changes in any variables were evident following 2MVCs. The 2d and 4d groups showed 16-62 % smaller (P < 0.05) changes in all variables following MaxECC than the control, 0d and 7d groups. The 2d group showed 14-34 % smaller (P < 0.05) changes in all variables except for OA compared with the 4d group. The changes in the variables were similar among the control, 0d and 7d groups. These results show that 2MVCs that were performed between 2 and 4 days before MaxECC attenuated the magnitude of muscle damage, but no such effect was evident if the 2MVCs were performed immediately or 7 days before MaxECC. It is concluded that the protective effect conferred by 2MVCs is relatively short-lived, and there is a window for the effect to be conferred.

History

Journal

European journal of applied physiology

Volume

113

Issue

6

Pagination

1545 - 1554

Publisher

Springer

Location

Berlin, Germany

eISSN

1439-6327

Language

eng

Publication classification

C Journal article; C1.1 Refereed article in a scholarly journal

Copyright notice

2013, Springer-Verlag Berlin Heidelberg