Abstract:
The purpose of this research was to study electromyographic activities (EMG) of the knee extensors of six training programs with different resting intervals. Six training programs included three courses of combined concentric with eccentric training with a resting interval of 30 seconds, 2 minutes and 4 minutes, and three courses of eccentric training with the same resting periods. Fourteen male subjects were purposively sampled from Faculty of Sports Science, Chulalongkorn University, aged between 18 20 years old. The subjects were trained in all of six programs. Each program was performed 2 sets. The total length of this research was six weeks, one program per week. The subjects were tested to determine their relative strength by a leg press position from 90 degree of knee flexion before trainings. EMG were recorded during the trainings, and processed by using root mean square values. EMG from each muscle were normalized by converting to the percentages. EMG was obtained during maximal voluntary contraction. The obtained data were analyzed in terms of means and standard deviations. T- test were used to determine the significant differences of the obtained data at the level of .05. The results showed that : 1. The effect of 30 seconds resting interval on percentages of maximal voluntary contraction in Rectus femoris, Vastus medialis and Vastus lateralis during the combined concentric with eccentric training and the eccentric training were not significantly different. 2. The effect of 2 minutes and 4 minutes resting interval on percentages of maximal voluntary contraction in Rectus femoris, Vastus medialis and Vastus lateralis during the combined concentric with eccentric training and the eccentric training in set 2 were significantly decreased at .05 level