Subjective-objective fit in tennis racket string-tension selection: perceived comfort, hitting performance, and fastest swing-speed associations.

BACKGROUND: Tennis racket string tension may influence ball speed, directional control, and perceived comfort, yet evidence from real hitting tasks remains limited. OBJECTIVE: This study examined the effects of five string tensions on forehand and backhand performance and tested whether subjective comfort aligns with objectively optimal tension. METHODS: Twenty-seven trained tennis players completed a repeated-measures experiment using five identical rackets strung at 40, 45, 50, 55, and 60 lb. Ball speed was derived from high-speed video, accuracy was scored using a concentric target, and perceived comfort was assessed using a 5-point Likert scale and final preferred-racket selection. Ball speed and accuracy were analyzed using 2 hitting sides × 5 string tensions × 2 sex groups mixed-design ANOVAs. Correlations examined associations among fastest racket swing speed, subjectively preferred tension, and individualized optimal-tension outcomes. RESULTS: Forehand ball speed was significantly higher than backhand ball speed, F(1,25) = 41.51, p < 0.001, ηp2 = 0.624. String tension did not significantly affect ball speed, whereas accuracy differed significantly across tensions, F(4,100) = 40.37, p < 0.001, ηp2 = 0.618, generally improving at higher tensions. A significant tension × sex interaction was also observed for accuracy, F(4,100) = 4.22, p = 0.003, ηp2 = 0.144. Fastest racket swing speed was positively associated with ball speed at the speed-optimal tension for both strokes, but not with optimal-tension values or best accuracy scores. Subjectively preferred tension showed limited agreement with objective speed- or accuracy-optimal tension, and no correlations remained significant after FDR correction. CONCLUSION: Within 40-60 lb, string tension influenced accuracy more consistently than ball speed. Perceived comfort provides complementary information but should not replace objective performance testing in individualized racket configuration.