2012 UKSCA poster

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EFFECT OF SQUAT TYPE ON POSTACTIVATION POTENTIATION Joseph I. Esformes 1† , Annicka Jones 1 , Jeremy Moody 1 , and Theodoros M. Bampouras 2 1 Cardiff Metropolitan University, Cardiff School of Sport, Cardiff, UK 2 University of Cumbria, Faculty of Health and Wellbeing, Lancaster, UK Introduction: Postactivation potentiation (PAP) refers to increased muscular force generation due to previous muscular activity. The use of strength-power potentiating complex pairs for enhancing power performance often entails the use of a heavy load squat exercise followed by a jumping, ballistic activity. However, in addition to the load, the variation in the depth to which the squat is performed can affect the performance outcome. For example, different squat depths can have different mechanical and physiological demands (Caterisano et al, 2002; Drinkwater et al, 2012), which could yield different PAP levels and subsequent performance. Therefore, the aim of the study was to compare the effect of prior execution of parallel (PS) or quarter squats (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 baseline countermovement jump (BL-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 (POST-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 BL-CMJ and POST-CMJ 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: The subjects’ 3RM load for PS and QS were 183.3±17.3 kg and 200.7±17.3 kg, respectively. All POST-CMJ variables improved significantly compared to BL-CMJ for both PS and QS (P<0.05; Table 1). In addition, delta values for PS were significantly higher than QS for all variables examined (P<0.05; Table 1). Table 1. Performance variables scores (mean±SD) for countermovement jump (CMJ) before (BL-CMJ) and after (POST-CMJ) the quarter and parallel squat conditioning contraction stimuli and Δ values (difference POST-CMJ – BL-CMJ). Discussion: 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 following parallel squats. 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. Corresponding author: [email protected] UK Strength & Conditioning Association, Royal Holloway College, London, UK, 15–16 September, 2012 Quarter Squat Parallel Squat Variables BL-CMJ POST-CMJ Δ BL-CMJ POST-CMJ Δ Jump Height (cm) 36 ± 4 40 ± 4* 3.5 ± 2 36 ± 4 41 ± 4* 4.6 ± 2 Impulse (N•s) 247 ± 22 259 ± 23* 12 ± 5 247 ± 24 262 ± 24* 15 ± 6 Peak power (W) 4367 ± 393 4582 ± 397* 215 ± 96 4367 ± 427 4652 ± 405* 285 ± 109 Flight time (ms) 545 ± 32 571 ± 32* 26 ± 11 545 ± 33 579 ± 31* 34 ± 13 *, significantly different to BL-CMJ (P < 0.05); †, significantly different to QS Δ values (P < 0.05).

Transcript of 2012 UKSCA poster

EFFECT OF SQUAT TYPE ON POSTACTIVATION POTENTIATION Joseph I. Esformes1†, Annicka Jones1, Jeremy Moody1, and Theodoros M. Bampouras2

1Cardiff Metropolitan University, Cardiff School of Sport, Cardiff, UK2University of Cumbria, Faculty of Health and Wellbeing, Lancaster, UK

Introduction: Postactivation potentiation (PAP) refers to increased muscular force generation due to previous muscular activity. The use of strength-power potentiating complex pairs for enhancing power performance often entails the use of a heavy load squat exercise followed by a jumping, ballistic activity. However, in addition to the load, the variation in the depth to which the squat is performed can affect the performance outcome. For example, different squat depths can have different mechanical and physiological demands (Caterisano et al, 2002; Drinkwater et al, 2012), which could yield different PAP levels and subsequent performance. Therefore, the aim of the study was to compare the effect of prior execution of parallel (PS) or quarter squats (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 baseline countermovement jump (BL-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 (POST-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 BL-CMJ and POST-CMJ 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: The subjects’ 3RM load for PS and QS were 183.3±17.3 kg and 200.7±17.3 kg, respectively. All POST-CMJ variables improved significantly compared to BL-CMJ for both PS and QS (P<0.05; Table 1). In addition, delta values for PS were significantly higher than QS for all variables examined (P<0.05; Table 1).

Table 1. Performance variables scores (mean±SD) for countermovement jump (CMJ) before (BL-CMJ) and after (POST-CMJ) the quarter and parallel squat conditioning contraction stimuli and Δ values (difference POST-CMJ – BL-CMJ).

Discussion: 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 following parallel squats. 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.

ReferencesBobbert and van Soest (2001). Exercise and Sport Science Reviews. 29, 95–102.Caterisano et al. (2002). Journal of Strength and Conditioning Research. 16, 428-432.Drinkwater et al. (2012). Journal of Strength and Conditioning Research. 26, 890-896.

†Corresponding author: [email protected]

UK Strength & Conditioning Association, Royal Holloway College, London, UK, 15–16 September, 2012

Quarter Squat Parallel SquatVariables BL-CMJ POST-CMJ Δ BL-CMJ POST-CMJ ΔJump Height (cm) 36 ± 4 40 ± 4* 3.5 ± 2 36 ± 4 41 ± 4* 4.6 ± 2†

Impulse (N•s) 247 ± 22 259 ± 23* 12 ± 5 247 ± 24 262 ± 24* 15 ± 6†

Peak power (W) 4367 ± 393 4582 ± 397* 215 ± 96 4367 ± 427 4652 ± 405* 285 ± 109†

Flight time (ms) 545 ± 32 571 ± 32* 26 ± 11 545 ± 33 579 ± 31* 34 ± 13†

*, significantly different to BL-CMJ (P < 0.05); †, significantly different to QS Δ values (P < 0.05).