Background/Purpose The effectiveness of aquatic and land based plyometrics is measured in the amount of time spent transitioning from eccentric to concentric movements (amortization) and ground contact time. Land-based training programs have been extensively investigated, but limited information examining aquatic-based plyometrics exists. The purpose of this study was to determine differences between aquatic and land-based plyometric training with respect to ground contact time.
Method Twelve (5 M; 7 F) healthy adults (27.4±3.0 yrs; 79.1±17.3 kg; 179.5±8.2 cm) not engaged in any formal exercise or any type of plyometric training program were randomly assigned into 2 groups (aquatic and land). Both groups received identical plyometric training sessions for 3 weeks, with increasing foot contacts each session, in each environment. Following sessions 2, 4, and 6 ground contact time was measured using a 17”x23” CVP switch mat on the land and in the water.
Analysis/Results Between-within subjects-groups repeated-measures ANOVA determined group by trial effects and interactions. Significance was set a priori at P<.05. A significant main effect for trials (F2,20=18.25, P<.001). Trial 1 (.97ms ±.33 ms) was significantly different than trial 2 (.71 ms ±.15 ms) and trial 3 (.61 ms ±.12 ms) and trial 2 was significantly different than 3.
Conclusions Both groups decreased their contact time over the trial periods similarly. There were no significant differences in ground contact time between the groups, suggesting that buoyancy may not adversely affect ground contact times, or the length of time spent in the amortization phase in the water during plyometric jumping as theorized.