EFFECTS OF IN-SEASON SHORT-TERM PLYOMETRIC TRAINING PROGRAM ON LEG POWER, JUMP- AND SPRINT PERFORMANCE OF SOCCER PLAYERS

Chelly, MS, Ghenem, MA, Abid, K, Hermassi, S, Tabka, Z, and Shephard, RJ. Effects of in-season short-term plyometric training program on leg power, jump-and sprint performance of soccer players. J Strength Cond Res 24(10): 2670-2676, 2010-Our hypothesis was that the addition of an 8-week lower limb plyometric training program (hurdle and depth jumping) to normal in-season conditioning would enhance measures of competitive potential (peak power output [PP], jump force, jump height, and lower limb muscle volume) in junior soccer players. The subjects (23 men, age 19 +/- 0.7 years, body mass 70.5 +/- 4.7 kg, height 1.75 +/- 0.06 m, body fat 14.7 +/- 2.6%) were randomly assigned to a control (normal training) group (Gc; n = 11) and an experimental group (Gex, n = 12) that also performed biweekly plyometric training. A force-velocity ergometer test determined PP. Characteristics of the squat jump (SJ) and the countermovement jump (CMJ) (jump height, maximal force and velocity before take-off, and average power) were determined by force platform. Video-camera kinematic analyses over a 40-m sprint yielded running velocities for the first step (V(S)), the first 5 m (V(5m)) and between 35 and 40 m (V(max)). Leg muscle volume was estimated using a standard anthropometric kit. Gex showed gains relative to controls in PP (p < 0.01); SJ (height p < 0.01; velocity p < 0.001), CMJ height p < 0.001; velocity p < 0.001, average power p < 0.01) and all sprint velocities (p, 0.001 for V(5m) and V(max), p < 0.01 for V(S)). There was also a significant increase (p < 0.05) in thigh muscle volume, but leg muscle volume and mean thigh cross-sectional area remain unchanged. We conclude that biweekly plyometric training of junior soccer players (including adapted hurdle and depth jumps) improved important components of athletic performance relative to standard in-season training. Accordingly, such exercises are highly recommended as part of an annual soccer training program.