Impact of Blood Flow Restricted Cycle Training in College-Aged Triathletes on Performance and Physiological Parameters

Abstract

Aerobic exercise training with blood flow restriction (BFR) has been reported to increase aerobic capacity and muscle strength and volume. However, there is no evidence that such a training strategy increases performance in athletes. PURPOSE: To elucidate the effects of a 4 week BFR cycle training protocol on aerobic capacity, muscle function and performance variables in triathletes of a university club. METHODS: Eighteen healthy university triathletes were randomly assigned to BFR group (n = 12; 19 ± 1 yrs) or no BFR group serving as the control (CON; n = 6; 20 ± 1 yrs). Both groups trained by cycling for 30 minutes, 3 days/week for 4 weeks. BFR was performed for 15 minutes total during each session as 5 minutes with BFR followed by 5 minutes without BFR, by applying cuffs to the upper thighs. The BFR group was further subdivided into two groups: one group with compression set to 160 mmHg (constant pressure, BFR-CP, n = 6); in the other, the compression was gradually increased from 160 to190 mmHg over 4 weeks (incremental pressure, BFR-IP, n = 6). All tests were performed before (Pre) and after 4 weeks of training (Post). Triathlon-specific performance tests were used: 5000-m run and 1500-m swim time trials and a 20-min bike distance trial, as well as the evaluation of peak oxygen uptake (VO2peak), one legged knee extensor strength, and thigh muscle cross sectional area (CSA). Two-way repeated ANOVAs were used (BFR vs CON or BFR-CP vs BFR-IP and Pre vs Post) with significance accepted as p<0.05. RESULTS: VO2peak significantly increased after the training (main effect of time) and significant group-by-time interactions were detected (3198 to 3449 mL/min and 3152 to 3212 mL/min in BFR and CON). However, a post-hoc analysis indicated no significant interaction in VO2peak between BFR-CP (3137 to 3396 mL/min) and BFR-IP (3259 to 3501 mL/min). Although the 5000-m run time was significantly shorter after the training (main effect of time), no significant interaction were detected (20.3 to 19.8 min and 20.1 to 19.8 min in BFR and CON). Lastly, there were no significant effects of training on muscle strength or CSA, 1500-m swim time, or 20-min bike distance. CONCLUSIONS: In this group of university triathletes, 4 weeks of BFR cycle training increased aerobic capacity, but had no added effect on muscle strength and volume or performance test outcomes.