Unlocking Greater Load Potential: How Cluster Sets Enable Higher External Loads

ABSTRACT: Nagatani, T, Kendall, KL, Vial, S, Comfort, P, Searle, P, Klaver, M, and Haff, GG. Unlocking greater load potential: How cluster sets enable higher external loads. J Strength Cond Res XX(X): 000-000, 2026-The aim of this study was to examine how altering external loads within cluster sets acutely affects barbell kinematics, compared with traditional sets performed at lighter loads. Twenty strength-trained individuals performed 3 sets of 9 power cleans (relative 1 repetition maximum [1RM]: 1.21 ± 0.16 kg·kg-1) using 3 experimental protocols performed in a randomized repeated-measures design: traditional sets with 70% 1RM (TRAD), cluster sets of 3 with 30-second intraset rest between every 3 repetitions and 85% 1RM (CLU-3), and cluster sets of 1 with 30-second inter-repetition rest and 90% 1RM (CLU-1). A linear mixed-effects model was used to examine the effects of session and repetition on barbell peak velocity (PV). In addition, statistical parametric mapping was used to conduct waveform analysis of the vertical displacement-time and horizontal displacement-time curve data, respectively. TRAD resulted in the highest PV, but subjects experienced clear signs of fatigue over the course of a high-volume power clean bout, as indicated by declines in PV (velocity loss = -0.17 ± 0.02 m·s-1) and significant changes in vertical and horizontal barbell displacements (p ≤ 0.05) across the set. Conversely, both CLU-3 and CLU-1 allowed subjects to better maintain PV (velocity loss = -0.11 ± 0.03 and -0.03 ± 0.03 m·s-1, respectively) and relatively consistent barbell trajectories across the set, despite showing lower PV overall due to the use of greater external loads when compared with TRAD. Based on the results of this study, cluster sets can be designed to not only modulate exercise-induced fatigue and maintain lifting technique but also increase external loads during high-volume power clean sessions.