Influence of rest intervals after assisted jumping on bodyweight vertical jump performance.

Assisted jumping (an overspeed concept) is a method used to improve vertical jump performance. However, research is lacking on the optimal program design to maximize performance outcomes. The purpose of this study was to determine the influence of rest intervals after assisted jumping on bodyweight (BW) vertical jumps. Twenty healthy recreationally trained men (age: 22.85 ± 1.84 years; height: 179.44 ± 5.99 cm; mass: 81.73 ± 9.51 kg) attended 5 sessions. For all sessions, subjects performed the same dynamic warm-up and then executed 1 set of 5 consecutive assisted jumps at 30% BW reduction. They then rested for 30 seconds (C30), 1 minute (C1), 2 minutes (C2), or 4 minutes (C4), followed by 3 BW jumps with no assistance. Baseline (CB) jump height was measured without preceding assisted jumps. Analyses of variance revealed a main effect for takeoff velocity, with 1 and 4 minutes being greater than baseline (C1: 3.36 ± 0.40 m·s(-1); C4: 3.27 ± 0.41 m·s(-1); CB: 3.13 ± 0.32 m·s(-1)). Relative peak power also demonstrated a main effect, with 1 minute being greater than all other conditions (C1: 75.22 ± 10.83 W·kg(-1)). Jump height and relative ground reaction force demonstrated no differences between conditions. These results indicate overspeed jumping acutely enhances explosive BW jumping velocity and power. This acute performance enhancement is probably a result of increased motor neuron excitability and motor unit synchronization.