Effects of 6-week flywheel resistance training on tennis serve velocity and accuracy

This study analyzed the impact of a 6-week joint-specific flywheel-based resistance training program on serve velocity (SV) and serve accuracy (SA) in junior tennis players. Fourteen participants were assigned to either an experimental group (FG; N.=7) training with an inertial conical pulley or a control group (CG; N.=7). SV, SA, one-handed and two-handed overhead medicine ball throws (MBT) were measured preintervention, at 3 weeks, and at 6 weeks. A large main effect of time (F=5.371, P=0.012, η2=0.309) and nonsignificant group- by-time interaction (F=2.102, P=0.144, η2=0.149) was found in SV. The FG demonstrated significant increases in SV from pretest to intertest (7.1 km·h-1, 4.5%, P=0.023, ES=1.5) and from pretest to posttest (7.3 km·h-1, 4.7%, P=0.035, ES=1.5). No changes in SV were observed in the CG. SA and MBT did not show significant changes over time in FG or CG. These findings suggest that incorporating flywheel-based joint-specific exercises into training programs positively affects SV without SA impairments in junior tennis players within a relatively short timeframe. Coaches can integrate similar layouts into training to optimize player performance.