Comparison of Loaded Countermovement Jump with Different Variable Resistance Intensities on Inducing Post-Activation Potentiation

Abstract

The aim of the study was to establish the optimum variable resistance (VR) intensity for loaded countermovement jump (LCMJ) to induce post-activation potentiation (PAP). Eleven male athletes (age 23 ± 2.3 years, height 1.77 ± 0.05 m, body mass 73.7 ± 9.0 kg) attended one familiarization and four testing sessions. Subjects performed their own pre-competition warm up before performing two countermovement jumps (CMJ) for baseline measure. Subsequently, they performed 2 × 3 unloaded (UCMJ) or loaded CMJ (LCMJ) with one of the three VR intensities, Orange (6.7 ± 0.6 kg), Red (14.0 ± 0.9 kg) and Blue (24.0 ± 1.4 kg), in random order, before performing two more CMJ for post-test measure. Each testing session was separated by at least 48 h. There was significant increase in jump height in all conditions (P 0.05). There were small to moderate effect when comparing Orange and the other conditions. Peak force and velocity increased in Red (P < 0.05) and Orange (P < 0.05), respectively. Change in jump height was significantly correlated to change in peak velocity (r = 0.46, P = 0.002) and peak power (r = 0.46, P = 0.002). The findings of the study showed that UCMJ and LCMJ were effective in improving jump height acutely, and an intensity level of about 10% body weight contributed by VR seems to be the optimum resistance level.