Effects of 8-week ischemic preconditioning on swimming performance and power output in male 100-m freestyle swimmers: a randomized controlled trial.

Purpose: This study aimed to investigate the long-term effects of an 8-week ischemic preconditioning (IPC) intervention on the athletic performance of male freestyle swimmers.

Methods: Eighteen male 100-m freestyle swimmers were randomly assigned to either the IPC group (n = 9) or the sham operation group (n = 9), with interventions administered three times per week over the course of 8 weeks. Athletic performance was evaluated through 100-m freestyle race tests and Wingate 30-s tests at baseline, at the 4th week, and at the 9th week. The data were analyzed via two-way repeated-measures ANOVA.

Results: After 8 weeks of intervention, the IPC group demonstrated significantly improved performance in the 100-m race compared with the placebo group (57.57 ± 2.30 vs. 59.90 ± 2.30, p = 0.048, d = 1.01). The enhancement in the second half of the 100-m performance was more pronounced in the IPC group than in the placebo group (30.15 ± 1.00 vs. 32.32 ± 1.97, p = 0.009, d = 1.39). Significant increases in peak power (817.27 ± 144.77 vs. 674.93 ± 54.75, p = 0.014, d = 1.30), mean power (679.60 ± 85.12 vs. 541.64 ± 78.33, p = 0.003, d = 1.69), and blood lactate levels (16.07 ± 1.22 vs. 14.7 ± 0.97, p = 0.018, d = 1.24) were detected. Conversely, a significant decrease was noted in the fatigue index (51.28 ± 6.20 vs. 60.34 ± 10.60, p = 0.042, d = 1.04) and time to peak (2942.67 ± 1782.08 vs. 4758.00 ± 1830.71, p = 0.049, d = 1.00).

Conclusion: An 8-week IPC intervention can effectively enhance the athletic performance of freestyle swimmers, potentially by improving anaerobic power output and delaying fatigue, as measured by the Wingate 30 s test. This finding suggests a novel intervention strategy for swim training.