Physical Fitness Level of Volleyball Extracurricular Students at SMK Negeri 4 Palembang: The Effects of Depth Jumps and Jumps to Box Training on Leg Muscle Explosive Power

Abstract

Objectives. This study aimed to determine the effect of two plyometric training methods—depth jumps and jumps to box—on leg muscle explosive power among volleyball extracurricular students at SMK Negeri 4 Palembang.

Materials and Methods. A total of 30 male students were divided into two equal groups. Group A (n=15) performed depth jumps; Group B (n=15) performed jumps to box. Both groups trained for 16 sessions across four weeks. A vertical jump test was conducted pre- and post-intervention to measure explosive leg power.

Results. The depth jumps group improved from a mean pre-test score of 38.00 to 44.87, while the jumps to box group improved from 36.27 to 42.13. Independent sample t-tests showed significant improvement in both groups (p < 0.05), with greater gains in the depth jumps group.

Conclusions. Both training methods significantly improved leg muscle explosive power, with depth jumps showing superior effectiveness. These findings can be applied in school sports programs to enhance volleyball performance.