Comparative effects of unilateral and bilateral plyometric training on physical fitness in adolescent team-sport athletes: a systematic review and meta-analysis

Objective This study aimed to compare the relative effects of unilateral and bilateral plyometric training on jump, sprint, and change-of-direction performance in adolescent team-sport athletes. Methods A systematic search was conducted in PubMed, Web of Science, Scopus, and Embase databases. Effect sizes were calculated from pre- and post-training changes and pooled using a random-effects model, expressed as SMD (Hedges’ g) and its 95% CI. Results A total of 11 studies involving 388 participants were included. Between-group comparisons showed no significant differences for countermovement jump (CMJ) (SMD = −0.06, 95% CI −0.32 to 0.20, I² = 0%, p = 0.649), standing long jump (SLJ) (SMD = −0.20, 95% CI −0.55 to 0.15, I² = 0%, p = 0.268), ≤10 m sprint (SMD = −0.22, 95% CI −0.53 to 0.09, I² = 0%, p = 0.164), ≥20 m sprint (SMD = −0.06, 95% CI −0.31 to 0.20, I² = 0%, p = 0.669), or change-of-direction (COD) (SMD = −0.01, 95% CI −0.33 to 0.31, I² = 27.9%, p = 0.946). Unilateral plyometric training showed greater improvements in single-leg tasks, including single-leg CMJ (SMD = 0.34, 95% CI 0.07 to 0.61, I² = 0%, p = 0.013) and single-leg COD (SMD = −0.61, 95% CI −1.01 to −0.21, I² = 0%, p = 0.003). Conclusion This study found no clear between-group advantage between unilateral and bilateral plyometric training for bilateral jump performance (CMJ and SLJ), sprint performance (≤10 m and ≥20 m), or COD. However, unilateral plyometric training appeared to provide greater benefits in single-leg tasks, particularly single-leg CMJ and single-leg COD, suggesting a possible task-specific advantage. Systematic review registration https://www.crd.york.ac.uk/prospero/ , identifier PROSPERO CRD420261324213.