EFFECT OF SQUAT TYPE ON POSTACTIVATION POTENTIATION

Abstract

PURPOSE: Postactivation potentiation (PAP) refers to increased muscular force generation due to previous muscular activity. Resistance exercise has been shown to induce PAP, therefore enhancing performance of a subsequent biomechanically similar explosive movement. Various interventions have been examined as potential PAP stimuli, with squats being the more effective one (e.g. Esformes et al, 2010). However, different squat types could yield different PAP and subsequent performance benefits due to different mechanical and physiological demands (Caterisano et al, 2002; Drinkwater et al, 2012). The aim of the study was to compare the effect of two commonly used squats, the parallel (PS) and quarter (QS), on PAP. METHODS: Twenty seven male, semi-professional rugby union players (mean±SD: age, 18±2 yrs; body mass, 87.19±5.42 kg; height, 180.7±5.14 cm) performed a countermovement jump (CMJ) followed by a 10 min rest and then 3 repetitions of either a PS or QS, at their respective 3RM loads, in a randomised, counterbalanced order. Following a 5 min rest, the subjects performed another CMJ. CMJ jump height (JH), peak power (PP), impulse (I), and flight time (FT) were assessed using a jump mat (Smartspeed, Brisbane, Australia). Pairwise comparisons between pre- and post-squat values for all variables were conducted for each squat type to examine whether PAP was induced. Additionally, delta values were compared to examine whether one squat type produced better CMJ results. RESULTS: Both squats induced PAP for all of the variables examined (P < 0.05), whilst the PS produced better results in all variables (P < 0.05). CONCLUSION: This is the first study to demonstrate that a) different squat types can induce PAP, and b) parallel squats have a more beneficial acute effect on CMJ performance compared to quarter squats. It has previously been shown that the gluteus muscle plays an important part in CMJ performance (Bobbert and van Soest, 2000). The deeper depth of the parallel squat activates this muscle more (Caterisano et al, 2002), possibly explaining the increased CMJ performance. However, as the movement demands of the two squats are also different, future studies should examine the mechanical characteristics of these two squats and their effect on the CMJ characteristics when PAP is induced.