Purpose: Inertial flywheel device (YoYo Technology) is well known to induce strength adaptations and increase muscle mass after short term training. (Norrbrand 2011, Tesch 2004). Changes in muscle architectural parameters appropriate to improve peak torque has been described (Seynnes, 2007). However these adaptations were not directly related to specific performances like jump, velocity and change direction ability. Aim of the study is to evaluate quadriceps strength and architecture, lower limb fat free mass, and performance parameters after short term YoYo squat training. Methods: 31 healthy young males has been randomly assigned at training (TR) or control (CON) group. TR underwent 16 training sessions in 9 weeks each consisting in 60 maximal reps at YoYo squat. Maximal Voluntary Contraction (MVC), Fat Free Mass (FFM), Fascicle length and thickness, Squat Jump (SJ) and Countermovement Jump (CMJ) Height and time on 30m dash and 20m shuttle have been measured pre and post training. Analysis of covariate has been done after log transformation. Results: Compare to CON, TR showed higher MVC isometric (avg 25%, CI 95 13% to 38%), concentric (10%, 2%to 19%), eccentric (9%, 2% to 17%) extension (for each parameters, p<0,01). In TR, FFM (4%, 1% to 7%), fascicle length (8%, 1% to 16%), fascicle thickness (6%, 1% to 15%) increased compare to CON (p<0,01). SJ (9%, 2% to 16%), CMJ (8%, 1% to 14%), 20m shuttle(-4%, -7% to -1%) significantly improve (p<0,05) in TR compare to CON. 30m dash did not improve significantly compare to CON(-1%, -4% to2%, p=0,445), indicating that 20m shuttle performance is specially due by an augmented control of decreasing and increasing speed. Conclusion: Augmented strength and changed muscle structure are in agreement with previous study. Longer fascicle is correlated with higher velocity of sarcomere contraction (Blazevich 2006). Outcomes show positive transfers in sport performance tasks, like jumping or braking and change sprinting direction. Flywheel device can be successfully used to improve performance in sport in which jumping or speed are key factors. Blazevich A.J.,et al. J Anat 2006, 209:289–310 Norrbrand L, et al. Aviat Space and Environ Med 2011,82(1):13-9. Seynnes OR, et al J. Appl Physiol 2007, 102(1):368-73. Tesch PA, et al. Acta Physiol Scand 2004, 180(1):89-98.

Effects of Squat Flywheel Training on Strength, Muscle Structure and Performance.

CORATELLA, Giuseppe;SCHENA, Federico
2012

Abstract

Purpose: Inertial flywheel device (YoYo Technology) is well known to induce strength adaptations and increase muscle mass after short term training. (Norrbrand 2011, Tesch 2004). Changes in muscle architectural parameters appropriate to improve peak torque has been described (Seynnes, 2007). However these adaptations were not directly related to specific performances like jump, velocity and change direction ability. Aim of the study is to evaluate quadriceps strength and architecture, lower limb fat free mass, and performance parameters after short term YoYo squat training. Methods: 31 healthy young males has been randomly assigned at training (TR) or control (CON) group. TR underwent 16 training sessions in 9 weeks each consisting in 60 maximal reps at YoYo squat. Maximal Voluntary Contraction (MVC), Fat Free Mass (FFM), Fascicle length and thickness, Squat Jump (SJ) and Countermovement Jump (CMJ) Height and time on 30m dash and 20m shuttle have been measured pre and post training. Analysis of covariate has been done after log transformation. Results: Compare to CON, TR showed higher MVC isometric (avg 25%, CI 95 13% to 38%), concentric (10%, 2%to 19%), eccentric (9%, 2% to 17%) extension (for each parameters, p<0,01). In TR, FFM (4%, 1% to 7%), fascicle length (8%, 1% to 16%), fascicle thickness (6%, 1% to 15%) increased compare to CON (p<0,01). SJ (9%, 2% to 16%), CMJ (8%, 1% to 14%), 20m shuttle(-4%, -7% to -1%) significantly improve (p<0,05) in TR compare to CON. 30m dash did not improve significantly compare to CON(-1%, -4% to2%, p=0,445), indicating that 20m shuttle performance is specially due by an augmented control of decreasing and increasing speed. Conclusion: Augmented strength and changed muscle structure are in agreement with previous study. Longer fascicle is correlated with higher velocity of sarcomere contraction (Blazevich 2006). Outcomes show positive transfers in sport performance tasks, like jumping or braking and change sprinting direction. Flywheel device can be successfully used to improve performance in sport in which jumping or speed are key factors. Blazevich A.J.,et al. J Anat 2006, 209:289–310 Norrbrand L, et al. Aviat Space and Environ Med 2011,82(1):13-9. Seynnes OR, et al J. Appl Physiol 2007, 102(1):368-73. Tesch PA, et al. Acta Physiol Scand 2004, 180(1):89-98.
inertial flywheel; sports performance; strength training
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11562/573350
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