Received December 23, 2015; Accepted February 24, 2016.
Abstract
PURPOSE The purpose of this study was to examine the effects of muscle contraction speed on number of repetitions, exercise duration and muscle activation during push-up exercise in men. METHODS The study employed a randomized, counter-balanced crossover design with two testing sessions that were 3 months apart. Twelve, healthy, male collegiate students were asked to perform two exercises separately, normal-speed push-up (ECC: 1-s, CON: 1-s) and speedy-push-up (maximum speed), until repetition failure of volitional contraction.
Outcomes were number of repetitions, exercise duration and muscle activation of the pectoralis major measured through surface electromyography (sEMG) during push-up exercises. The sEMG data were normalized to maximal voluntary isometric contraction (MVIC) and expressed as a percentage (%MVIC) in both ECC phase and CON phase. RESULTS Number of repetitions (t=-5.352, p<.001), exercise duration (t=-5.837, p<.001) and muscle activity (t=-4.525, p=.023) were significantly different between two exercise conditions. CONCLUSIONS Normal-speed push-up exercise increased exercise duration and muscular activity while, and speedy push-up exercise increased number of repetitions. Further studies are warranted to elucidate associations between muscle adaptation stimulus and muscle contraction speed.
Keywords :
push-up exercise, muscle contraction speed, number of repetitions, exercise duration, muscle activation