The effects of dumbbell versus TRX suspension training on shoulder strength, vertical jump, and spike speed in volleyball players

BACKGROUND: Limited research exists on how various resistance training methods, such as TRX and dumbbells, impact sport-specific technical skills and muscle performance in young athletes. OBJECTIVE: This study aimed to compare the effects of 8-week Total-Body Resistance Exercise (TRX) suspension training and Traditional Dumbbell Training (TDT) on shoulder muscle strength, leg power, and spike speed in young male volleyball players. METHODS: Twenty-five male volleyball players were randomly assigned to either the TRX suspension group (n = 13) or the TDT group (n = 12). Anthropometric measures, countermovement jump (CMJ) height, spike speed, and shoulder joint isokinetic strength tests were conducted pre- and post-intervention. Both groups continued their volleyball training (5 days/week) and added TRX or TDT sessions for 2 months (60-90 minutes/day, 3 times/week), including 8 multi-joint exercises (1-3 sets/12 reps, 60 min rest). Statistical analysis involved Mann-Whitney and Wilcoxon tests, with effect size calculations. RESULTS: Compared to the TDT group, the TRX group showed significant improvements in CMJ height (+12.17% vs. +0.83%; p = 0.001), CMJ power (+9.55% vs. -0.24 %; p = 0.01), and spike speed (+11.49% vs. +6.82%; p = 0.03) with a small to moderate effect size. CONCLUSIONS: In young male volleyball players, TRX suspension training may be more effective than dumbbell training in enhancing jump performance and spike speed.