Time-specific post-activation performance enhancement after drop jump and optimal-load jump squat in young elite rhythmic gymnasts

Abstract Background This study compared the acute effects of drop jump and jump squat with optimal power load on countermovement jump height at various rest intervals, and examined the relationships between strength level and the individual peak countermovement jump height. Eleven elite youth rhythmic gymnasts completed three randomized crossover sessions: one set of six drop jump repetitions, one set of six jump squat repetitions, and a control condition. Countermovement jump height was measured before, 30 s, 3 min, 6 min, and 9 min after each condition. Analyses included repeated-measures comparisons across time and baseline vs. each athlete’s individual peak; correlations tested relationships with relative back squat maximum strength. The two-way repeated-measures analysis of variance showed a condition × time interaction ( F (8, 80) = 3.685, p = 0.001, η 2 = 0.269) and a main effect of time ( F (4, 40) = 3.61, p = 0.013, η 2 = 0.265). Post hoc tests indicated that the jump squat condition significantly improved countermovement jump height at 3 min than at 6 min ( p = 0.015, d = 0.42). A greater improvement at 30 s was observed after drop jump than after jump squat ( p = 0.023, d = 0.49). No fixed post-conditioning time point showed a significant increase compared with baseline. However, individual peak analysis indicated higher CMJ height than baseline in both drop jump ( t = 4.068, p = 0.002, d = 0.42) and jump squat ( t = 2.844, p = 0.017, d = 0.35) conditions. No correlation ( r = – 0.404 to 0.05, p = 0.218 to 0.924) was found between maximum strength and post-intervention peak countermovement jump height. In early-adolescent rhythmic gymnasts, drop jump may offer an earlier, small enhancement of countermovement jump performance. Given the heterogeneity in time-to-peak, individualized timing rather than fixed windows is recommended for pre-performance routines.