Influence of trunk strength on sprint performance in swimmers: a cross-sectional analysis of torque-velocity relationships

This cross-sectional study assessed trunk strength at 60°/s and 120°/s angular velocities in swimmers and its relationship to 100-m sprint performance. Thirty-two elite swimmers (age: 19.49 ± 1.44 years; height: 177.77 ± 6.84 cm; body mass: 71.88 ± 8.50 kg) underwent isokinetic trunk testing and timed sprints. All tests demonstrated excellent reliability (ICC 0.96). Swimmers had significantly greater peak torque in extension compared to flexion ( p 0.01), and higher torque in left versus right rotation, though the latter was not significant. Contrary to the hypotheses, peak torque at 120°/s did not correlate more strongly with performance than at 60°/s, and rotation torque did not surpass flexion/extension metrics. After Benjamini–Hochberg FDR correction for 24 comparisons, no significant correlations remained (q 0.05), indicating initial associations were likely confounded by sex differences. These results suggest training should emphasize inter-segmental coordination over isolated strength gains, focusing on torque transfer from trunk to extremities. Interpretation of high-velocity torque data requires caution due to potential acceleration artifacts at early peak angles (5°–7°).