The Effect of Variable Resistance Training on Post-Activation Performance Enhancement: A Systematic Review and Three-Level Meta-analysis

BACKGROUND: Variable resistance training (VRT) has been proposed as a practical conditioning strategy to acutely enhance subsequent performance, but the evidence for its ability to induce post-activation performance enhancement (PAPE) remains inconsistent. This study systematically quantified the acute effect of VRT on PAPE using a systematic review with a three-level meta-analysis and explored key moderating variables. METHODS: Following PRISMA guidelines, systematic searches were conducted in PubMed, Web of Science, and EBSCO databases. Given the nested effect sizes within studies, a three-level meta-analysis model was employed to calculate Hedges' g, supplemented by subgroup analyses and meta-regression. RESULTS: Thirteen studies (95 effect sizes) were ultimately included. Main effects analysis revealed a significant modest effect of VRT on PAPE (k = 95, g = 0.27, p = 0.0016), though with substantial heterogeneity (I²= 60.1%). Subgroup analysis indicated significant modest improvements in jump performance: Tier-3 participants (g = 0.22) exhibited significant PAPE effects, whereas Tier-2 showed no significant effect; furthermore, PAPE effects were significant for multi-set training (g = 0.43, p = 0.002) and for equal intensity VRT designs (g = 0.39, p = 0.003). CONCLUSION: Acute VRT constitutes an effective strategy for inducing PAPE, yielding small to moderate positive effects. For the acute elicitation of PAPE, high-level athletes may benefit from using VRT during warm-ups or complex training, particularly when multiple sets, an equal-intensity design, and a relatively high proportion (≥ 30%) of variable resistance loading are applied.