Immediate effect of assisted and resisted training using different weight balls on ball speed and accuracy in baseball pitching

Abstract

The purpose of this study was to investigate the immediate effects of assisted and resisted training using different weight balls on ball speed and accuracy in baseball pitching. Eight male university baseball players were assigned as subjects. The experiment used a standard 145-gram baseball and two heavier or lighter balls with weights increased or decreased by 10% respectively. The subjects were required to pitch these balls and/or standard ball either six or eighteen times under different training trial conditions: 1) pitching the weighted ball only, 2) pitching the lightened ball only, 3) pitching the standard ball only, and 4) pitching three kinds of balls in order of the weighted, standard and lightened balls. Immediately after each training trial, the standard ball was pitched five times respectively (test trial). The ball speed of each trial was measured with a speed gun, and the distance from the center of target to the position of the ball pitched on the target was calculated using a video digitizing system. The results are summarized as follows: 1) In the training trials, the ball speed increased as the ball weight was decreased. 2) In the test trials, immediately after pitching the lightened ball both six (6A_test) and eighteen times (18A_test), and the three different kinds of balls eighteen times (18C_test), the ball speeds were seen to be significantly higher than that of other test trials (p<0.01). 3) Although there were no significant differences in the ball speed in the above three test trials, a relatively higher ball speed was observed in 18A_test. 4) As for the distance from the center of target to the position of the ball pitched on the target, there were no significant differences among any trials.