Plyometrics is a type of training methodology that can increase power output and explosiveness. Plyometrics involves an active muscle switching from a rapid eccentric muscle action to a rapid concentric muscle action or from a rapid deceleration to a rapid acceleration. This action of deceleration to acceleration is known as the stretch-shortening cycle. Muscles that start in a static position can not generate as much force as those using the stretch-shortening cycle since the eccentric to concentric muscle action uses the elastic energy stored in the muscle. A greater power output can be found when the stretch-shortening cycle is used because of the efficiency gained by releasing elastic energy stored in the muscles. The muscles react to the sudden stretch by sending a signal to the central nervous system to resist the sudden stretch. In other words, the muscle is going to rebound rapidly from the sudden stretch. Considering this information plyometric training has the potential to develop quicker reaction times that lead to an increase in an athlete’s speed and power. The study consisted of 30 male volleyball players from PSG College of Arts & Science, Coimbatore, their age ranged from 18 to 25 years. Subjects were randomly assigned Group I underwent plyometric training group and Group II control group. The plyometric training group carried out a set of plyometric exercises also designed by the researcher twice a week for six weeks. The control group was allowed to play their game, but they were not given any treatments. For the purpose of this research, two tests for the evaluation of the vertical jump were validated: vertical jump right foot and vertical jump left foot. The data was processed using Paired t-tests were used to test the effect of treatment groups individually between pre and post –tests of all the groups on variables used in the present study. The result of the study reveals that there was significant difference in 0.05 levels. Based on the findings of the research and the discussion, one could unfailingly conclude that the exercise model for the development of the vertical jump that had been used, as the fundamental factor of the experimental group, has contributed to the statistically relevant difference in the increase of the vertical jump in comparison to the control group, which had used technically tactical contents to develop the vertical jump and speed.

Keywords: Plyometrics, Vertical Jump and Speed