The effects of different velocity loss thresholds on post-activation performance enhancement in basketball players

Aim This study investigated the effects of different velocity loss (VL) thresholds during squat exercise at 80% of one-repetition maximum (1RM) on post-activation performance enhancement (PAPE) in basketball players. Methods Nineteen male collegiate basketball players completed three familiarization sessions and four randomized crossover experimental sessions: control (passive rest), 5% VL, 10% VL, and 20% VL. Countermovement jump height (JH), peak power output (PPO), and reactive strength index modified (RSIm) were measured pre-test and at 3-min and 8-min post-squat. Linear mixed-effects models (LMMs) evaluated the effects of time, condition, and mean-centered relative strength on the outcome variables and repetition counts. To identify responders who exhibited meaningful improvements in jump height, the smallest worthwhile change (SWC) was calculated. Results At the group level, no significant condition × time interactions or main effects of condition were observed for JH, PPO, or RSIm ( p > 0.05), indicating no uniform PAPE effect across protocols. Furthermore, no statistically significant strength × time × condition interaction effects were observed. Repetition counts did not differ between the 5% and 10% VL conditions but were significantly lower in both conditions compared to the 20% VL condition ( p < 0.01). Individual analysis showed the 20% VL condition yielded the highest number of responders ( n = 11; 58%). Conclusion Squat protocols using 5–20% VL at 80% 1RM did not produce significant group-level CMJ performance improvements, suggesting that a comprehensive warm-up may create a performance ceiling. Furthermore, these responses were not moderated by relative strength. However, the high inter-individual variability and responder rates at higher VL thresholds highlight the importance of individualized PAPE programming.