抄録
This study examined the effects of repeated drop jumps (DJs) on stretch-shortening cycle (SSC) performance, whole-body reaction time (RT), and anaerobic power (AP) output across different surface types. This study employed a cross-over design. The participants were 17 healthy male undergraduate and graduate students. All participants completed 5 sets of 10 DJs from a 30-cm platform on 2 surface types: rigid and soft elastic (soft surface). After repeated DJ exercises, participants rested for 10 minutes. Participants’ SSC performance (through DJ and rebound jump (RJ)), RT, and AP output were then evaluated using a bicycle ergometer. Results showed that repeated DJ exercises on a soft surface reduced SSC performance, as reflected in lower DJ and RJ indices. In particular, jump height decreased for DJ, but ground contact time was not affected for DJ and RJ. However, RT and AP output were not significantly affected by the soft surface. These results indicate that repeated landing on the soft surface disrupted SSC performance by altering pre-activation and stiffness regulation, likely due to mat deformation and lasting proprioceptive effects. Furthermore, the mismatch in SSC timing after exercise on the soft surface may result from modified proprioceptive feedback during landing. Thus, repeated DJs on a soft elastic surface impair SSC performance but do not influence RT or AP output.
