Effect of stable and unstable loads on post-activation performance enhancement in the countermovement jump
DOI:
https://doi.org/10.63750/f390w842Keywords:
water bag, force-time, jump kinematics, instability trainingAbstract
This study aimed to investigate the practicality of unstable loads and their effect on post-activation performance enhancement (PAPE), observed through force time kinematic variables in the countermovement jump (CMJ). Thirty-four collegiate male athletes participated in a randomized crossover experiment. Athletes were randomly assigned to first complete either the 20.4 kg barbell stable (ST) or 20.4 kg water bag unstable (US) load protocol After a 20-minute rest period, the subjects completed the other protocol. Protocols consisted of a baseline jump, two sets of three consecutive jumps with the load, then a second jump to retest. Force plate data were sampled at 1,000 Hz and predetermined landmarks of the force time curve were utilized to calculate key performance indicators. A two-way repeated measures ANOVA with condition (ST, US) and time (pre, post) as independent variables was used to assess outcome variables. Statistical significance was set at p < .05. No significant interaction or condition effects were present in findings (p > .05). Peak and average braking force (p = .001; p < .001 respectively), braking impulse (p < .001), takeoff velocity (p = .005), jump height (p = .006), center of mass (COM) depth (p = .006), and rate of force development (RFD) (p = .009) were all significantly different between the first and second jump for both ST and US conditions. The results of this study suggest that either stable or unstable loads may produce a PAPE effect, thus increasing the number of modalities available to achieve this outcome.
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Copyright (c) 2026 Anthony J Campbell MS, Charlie R Ottinger PhD, Lauren M Biscardi PhD (Author)
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