Effects of a Unilateral Plyometric Training Program and the Association of Training Motivation with Take-Off Power in Long-Jump Athletes

Abstract

Objectives: This study examined changes in take-off power following a unilateral plyometric training program and tested whether training motivation was associated with the magnitude of improvement among long-jump athletes from the Kuda Terbang Athletics Club, Bima City.

Materials and Methods: A one-group pretest–posttest quasi-experimental design was used. Ten active long-jump athletes aged 16–18 years were recruited through total sampling. The four-week intervention comprised three weekly sessions of single-leg hops, single-leg bounds, and single-leg box jumps. Take-off power was assessed with the Single-Leg Vertical Jump Test, and training motivation was measured with a 20-item Likert questionnaire (Cronbach’s α = 0.82). Data were analyzed using descriptive statistics, Shapiro–Wilk tests, a paired-samples t-test, and simple linear regression at α = 0.05.

Results: Mean single-leg vertical-jump height increased from 27.50 ± 3.02 cm to 28.30 ± 2.62 cm. The mean improvement was 0.80 cm (95% CI: 0.35–1.25), t(9) = 4.00, p = 0.003, with a large within-participant effect (dᵥ = 1.26). Motivation explained 56.2% of the variance in gain scores, F(1,8) = 10.264, p = 0.013; however, the association was negative (B = −0.099, β = −0.750), indicating smaller gains among athletes with higher motivation scores in this sample.

Conclusions: Four weeks of unilateral plyometric training were associated with a statistically significant improvement in take-off power. The negative motivation–gain association should not be interpreted causally because the study had only 10 participants, no control group, and restricted motivation scores. Larger controlled studies are required before drawing conclusions about motivation as a predictor of adaptation.