The Acute Effects Of Back Squats On Mechanical Variables During Countermovement Vertical Jump Performance In Women

Abstract

PURPOSE: The aim of the present study was to investigate the acute effects of performing back squats on subsequent performance during a series of vertical jumps in women. METHODS: Twelve women were tested on three separate occasions, the first of which was used to determine their 1-repetition maximum (1-RM) parallel back squat. Following this, subjects performed a potentiation and a control treatment in a counterbalanced order. The potentiation treatment culminated with subjects performing parallel back squats with a load equivalent to 70% 1-RM for three repetitions, following which they performed 10 countermovement vertical jumps (CMJ) for maximal height every three minutes on a force platform. During the control treatment, subjects performed only the CMJs. From the force platform, jump height (JH) and average rate of force development (aRFD) were recorded during each jump. RESULTS: The difference between the maximum JH following the potentiation and control treatments was not substantial (p > 0.050). However, a trend was noted in the difference between maximum aRFD following the two treatments (p = 0.063), with the squat treatment tending to reduce subsequent aRFD. A small positive correlation was found between normalized 1-RM back squat load and the absolute change in JH (r = 0.10), while a moderate negative correlation was found between normalized 1-RM load and the absolute change in aRFD (r = -0.45). Large variations in response to the back squats were noted in the subjects. CONCLUSION: The use of resistance exercises performed prior to a series of vertical jumps can result in improvements in performance in certain individuals, although the gains tend to be small and dependent upon the mechanical variable measured. Such individual responses may render such PAP protocols impractical for strength and conditioning practitioners as the protocols are likely to require individualizing to each athlete.