Effects of Three Modified Plyometric Depth Jumps and Periodized Weight Training on Lower Extremity Power (Report‪)‬

Introduction The term "plyometrics" refers to specific exercises which encompass a rapid stretching of muscle that is undergoing eccentric stress followed by a concentric, rapid contraction of that muscle for the purpose of developing a forceful movement over a short period of time (Chu, 1983). One particular plyometric activity, the depth jump, has been shown to improve power in the vertical jump (Batholemew, 1985; Miller, 1982; Parcells, 1977; Verkhoshanski & Tatyan, 1983). Depth jumps are a type of dynamic exercise where an individual steps off a box 20 to 80 centimeters in height, lands, and performs an explosive vertical jump (Wilson, Murphy, & Giorgi, 1996). The depth jump is thought to enhance vertical jump performance through the quickening of the amortization phase, which is the electromechanical delay from the initiation of eccentric to the initiation of concentric muscle actions of the movement (Steben & Steben, 1981).