Effects of acute caffeine ingestion on post-activation performance enhancement following individualized drop-jump conditioning in high-level male basketball players: a randomized, double-blind, placebo-controlled crossover trial

BACKGROUND: Post-activation performance enhancement (PAPE) is widely used as a pre-performance strategy to improve explosive performance. However, whether acute caffeine ingestion can further enhance PAPE following an individualized conditioning stimulus based on athletes' reactive strength profiles remains unclear. This study investigated the effects of acute caffeine ingestion on PAPE responses induced by a reactive strength index (RSI)-guided individualized drop-jump (DJ) protocol in high-level basketball players. METHODS: Twenty-one male National Athlete Grade I basketball players (Tier 3: Highly Trained/National Level) completed a randomized, double-blind, placebo-controlled crossover trial. Participants performed two experimental conditions involving caffeine ingestion (3 mg·kg-1 body mass) or placebo, combined with an RSI-guided individualized DJ conditioning protocol. Countermovement jump (CMJ) performance was assessed before and after conditioning at 15 s, 3 min, 6 min, 9 min, and 12 min. PAPE was defined as the change in CMJ height relative to the post-warm-up baseline. RESULTS: Individualized DJ conditioning induced a significant time-dependent change in CMJ performance, demonstrating a transient PAPE response (time effect, p < 0.001). However, caffeine ingestion did not significantly modify the temporal profile of PAPE compared with placebo (condition × time interaction, p > 0.05). No significant differences were observed between conditions in peak CMJ height, peak enhancement magnitude, time to peak performance, or cumulative PAPE responses (all p > 0.05). Individual response analysis indicated substantial variability in caffeine-related changes, while sensitivity analysis confirmed the stability of the temporal response pattern. CONCLUSION: Acute caffeine ingestion at 3 mg·kg-1 body mass did not provide additional ergogenic benefits beyond RSI-guided individualized DJ conditioning in high-level male basketball players. These findings suggest that individualized conditioning strategies may already optimize PAPE responses, with limited additional enhancement from acute caffeine supplementation under the investigated conditions.