Blood flow restriction combined with swimming sprint training does not improve performance in moderately trained swimmers

The goal of this work was to compare the effect of a 4-week period of sprint training with blood flow restriction (BFR) and a control group without BFR (CON) on swimming performance, stroke kinematics, and tethered force. A total of 19 male and female, moderately trained swimmers were divided into two groups: CON (n = 9, 3 women, 23 ± 4 years, 1.67 ± 0.07 m, 66.2 ± 8.6 kg) or BFR (n = 10, 3 women, 23 ± 4 years, 1.70 ± 0.09 m, 67.9 ± 9.4 kg). Both groups followed the same training program and intervention sets, except for the use of BFR. Average speed, stroke length, stroke rate, 50 m performance, and tethered swimming force were compared using repeated-measures analysis of variance (ANOVA). No significant changes were observed in stroke length, stroke rate, or 50 m performance in either group. Main time effect was observed in average speed (p = 0.005) and tethered force (p = 0.029), with no between-group differences. Within-group effect sizes were trivial to medium for all variables (−0.09 to 0.75). Adding BFR to sprint training for 4 weeks did not induce superior improvements compared to sprint training alone in the variables assessed in this study.