Acute Mechanical and Skin Temperature Responses to Different Interrepetition Rest Intervals During Full-Squat Exercise.

Abstract

This study aimed to (1)evaluate the acute effects of different interrepetition rest full-squat protocols on countermovement jump (CMJ) height, velocity loss (VL), and skin temperature (Tsk) and (2)determine whether the VL, the changes in Tsk, or the individual strength level is associated with the change in CMJ height. Sixteen resistance-trained men randomly performed 3 squat protocols at maximal intended velocity with 60% of the 1-repetition maximum (sets × repetitions [interrepetition rest]): traditional (2 × 6 [0s]), cluster 2 (2 × 6 [30s every 2 repetitions]), and cluster 1 (1 × 12; [36s every repetition]), plus a control session. CMJ height was assessed before and 2, 4, and 8minutes after the protocols. There was a significant main effect of protocol for the VL (F = 20.54, P < .001) and loss in mean power (F = 12.85, P < .001; traditional > cluster 2 > cluster 1). However, we found a comparable reduction of CMJ height after 8minutes: traditional (-3.4% [4.2%]), cluster 2 (-5.3% [4.9%]), cluster 1 (-5.4% [2.9%]), and control (-4.2% [3.6%]). Overall, mean Tsk acutely decreased after all the protocols. Higher individual strength level (but not VL or the changes in Tsk) was associated with lower CMJ-height loss (P < .05). Although different interrepetition rest full-squat protocols may alter the loss in velocity and power, they result in a similar decrease in Tsk and CMJ height, which could be more influenced by individual strength level than VL or changes in Tsk.