The effect of cluster sets and accentuated eccentric loading on vertical jump performance and strategy during lower-body complex training

This study assessed general and more detailed post-activation performance enhancement responses to cluster sets (CS) + accentuated eccentric loading (AEL) versus a traditional method (TRD) in vertical jump performance and strategy. Six men and six women completed lower-body complex training: countermovement jump was performed at baseline and 1-, 2-, 4-, and 6-min after back squat using CS + AEL and TRD in a randomized crossover manner. CS + AEL used 20 s of inter-repetition rests for back squat and 30% body mass dumbbells for countermovement jump (on the first repetition only across three repetitions at 2-, 4-, and 6-min post), unlike TRD. Data were analyzed as: condition × time (1-, 2-, 4-, and 6-min) and condition × time (2-, 4-, and 6-min) × rep (1, 2, and 3), with baseline as a covariate. Peak power was significantly (p < 0.05) decreased during CS + AEL at 4-min (g = −0.73) and increased during TRD at 2-min (g = 0.46) compared to respective baseline. Peak power was significantly reduced during CS + AEL at 4-min on rep 2 (g = −0.85) and 3 (g = −1.28) and elevated during TRD at 2-min on rep 3 (g = 0.72) compared to respective rep 1. Despite a significant interaction for concentric duration, none of the repetitions were statistically different compared to respective rep 1. CS + AEL compromised post-activation performance enhancement at 4-min post, potentially due to rep-to-rep decreases in peak power on rep 2 and 3, unlike TRD.