Acute effects of heavy-load squats on consecutive vertical jump performance

Introduction.-The aim of this study was to explore the effects of heavy-load concentric and isometric half-squats on consecutive counter-movement jump (CMJ) performance. Methods.-Seventeen young men (aged 20-35 years) participated in this study. Baseline CMJ was assessed using an accelerometer (Myotest Pro) and one RM back half-squat was assessed using a regular resistance training machine (Smith machine). 72 hours later, CMJ was assessed immediately after (CMJconc0), 2 minutes after (CMJconc2) and 4 minutes after (CMJconc4) three repetitions at 85% one-repetition maximum half-squat. Seventy-two hours later, CMJ was assessed immediately after (CMJiso0), 2 minutes after (CMJiso2) and 4 minutes after (CMJiso4) one isometric contraction at 100% one-repetition maximum half-squat. CMJconc0, CMJconc4, CMJiso0 and CMJiso4 values were significantly lower than baseline CMJ value. Conclusion.-This study shows negative effects of heavy-load half-squats on consecutive vertical jump (CMJ) performance. (C) 2010 Elsevier Masson SAS. All rights reserved.