The effect of flywheel training on functional neuromuscular performance in physically active youth

Aim The aim of this study was to investigate the effect of flywheel resistance training on functional neuromuscular performance in physically active youth. Method Forty-four healthy and physically active youth between 12-14 years of age (n=19 boys & n=25 girls) volunteered to participate and were randomized into three different groups of flywheel resistance training (FRT) (n=15, body mass = 42,9 ± 8,6 kg, time to Peak Height Velocity (PHV) = - 0,8 ± 1,6), traditional strength training (TST) (n=15, body mass = 44,7 ± 10,3 kg, time to PHV = - 0,8 ± 1,5) and a control group (CON) (n=14, body mass = 43,8 ± 9,0 kg, time to PHV- 0,8 ± 1,5. Squat jump (SQ), Countermovement jump (CMJ), 10-m acceleration, 20-m speed and 30-sprint was assessed pre- and post-intervention. All training groups performed 12 resistance training sessions over a 6-week intervention. The FRT-group performed bilateral flywheel resistance squats with 4 sets of 6 repetitions with 0,025 to 0,05 kgm2 and the TST-group performed bilateral barbell squats with 4 sets of 6 repetitions at a predicted 80 %1RM, while the control group only performed their regular sports training. Results Repeated measures two way-ANOVA, 3 x 2 (training group x time), showed no significant mean effects between groups after the intervention. A significant increase occurred in the control group for SQ; 2,4 ± 2,5 (cm) p ≤ 0,008 and CMJ; 2,2 ± 3,1 (cm) p ≤ 0,037. Both training groups increased significantly in body mass from pre- to post-tests by 2,0 ± 2,7 kg for the flywheel training group and 1,3 ± 0,9 kg in the traditional strength training group (p ≤ 0,05). Conclusions This study indicates that flywheel training can be used as a resistance training method for youth athletes without inducing training related injuries. Flywheel resistance training resulted in a small but non-significant increase from pre to post test in squat jump and 10-m sprint. Future studies on flywheel resistance training for youth needs to investigate the implementation of longer training periods, additional training sessions, more experienced youth in resistance training and faster movement speed