Effects of plyometric training on jumping, sprint performance, and lower body muscle strength in healthy adults: A systematic review and meta-analyses

Objective: To determine the effect of lower body plyometric training (PLY) on jumping, sprint performance, and lower body muscle strength in healthy adults. Methods: A systematic literature search (PubMed, Embase) was performed. Studies were included if they (a) described a lower body PLY intervention lasting >= 4 weeks; (b) included measures of jumping, sprint, and/or lower body muscle strength; (c) included healthy individuals >= 18 years; (d) included a training or non-training control group; and (e) were written in English. Meta-analyses identifying the effects of PLY on jumping, sprint, and lower body muscle strength were conducted providing the standardized mean difference (SMD). Results: A total of 826 records were identified of which 25 fulfilled the inclusion criteria, yielding 19, 11, and seven data points for the meta-analyses of jumping, sprint performance, and lower body muscle strength, respectively. The data showed improvements for all three performance variables after 4-12 weeks of PLY. The SMD (CI95%) across studies for jump height, sprint time, and muscle strength were 0.45 (0.16: 0.75), -0.59 (-1.01: -0.17), and 0.33 (0.03: 0.63), respectively, where the latter two showed within-sample heterogeneity. Conclusion: The systematic review and meta-analyses showed that PLY elicits a small-to-moderate positive effect on jumping, sprint performance, and lower body muscle strength in healthy adults being recreationally active or athletes.