The effects of exercise selection and rest interval on postactivation potentiation of vertical jump performance.

The purpose of this study was to determine if a power exercise would lead to greater postactivation potentiation (PAP) than a strength exercise, if a 4-or 5-minute rest interval led to greater PAP, the extent to which PAP was an individual phenomenon, and the effect of PAP on the ground reaction force (GRF) during a vertical jump (VJ). Subjects included 16 volleyball athletes (8 men and 8 women) from a Division I university. Participants were instructed to complete a pre-exercise countermovement jump for height. After the VJ, subjects performed 5 repetitions of either the back squat or hang clean (midthigh) with a load equal to their 5 repetition maximum (5RM). After the 5RM resistance exercise, countermovement jumps were completed at 4 or 5 minutes after the back squat or hang clean. Ground reaction force was measured using a force platform embedded in the ground, whereas VJ height was assessed using a Vertec jump apparatus. Data were analyzed using a factorial analysis of variance with repeated measures. Results revealed that there was no consistent rest interval or exercise that produced the largest increase in VJ height for all subjects, and there were no apparent differences because of gender. The condition that produced the largest increase in VJ height for each individual resulted in an average increase of 5.7% (2.72 +/- 1.21 cm; p < 0.001). There was no significant difference (p > 0.05) in peak GRF, and no significant correlation (r = -0.110, p = 0.707) between the increase in VJ height and increase in peak GRF. Results suggest that individually determining complex training variables will increase VJ height, thus acutely enhancing athletic performance.