Siatras TA, Mittas VP, Mameletzi DN, Vamvakoudis EA
This study was conducted to determine the acute effect of different static stretching durations on quadriceps isometric and isokinetic peak torque production. The 50 participants were randomly allocated into five equivalent sized groups and were asked to perform a stretching exercise of different duration (no stretch, 10-second stretch, 20-second stretch, 30-second stretch, and 60-second stretch). The knee flexion range of motion and the isometric and concentric isokinetic peak torques of the quadriceps were measured before and after a static stretching exercise in the four experimental groups. The same parameters were examined in the control group (no stretch) without stretching, before and after a 5-minute passive rest. Significant knee joint flexibility increases and significant isometric and isokinetic peak torque reductions have been shown to occur only after 30 and 60 seconds of quadriceps static stretching. Stretching reduced isometric peak torque by 8.5% and 16.0%, respectively. The authors suggest that torque decrements are related to changes of muscle neuromechanical properties.
Static stretching exercises of a muscle group for more than 30 seconds of duration should be avoided before performances requiring maximal strength.
Journal of Strength and Conditioning Research, 2008, 22(1), 40-6
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