Blood Flow Restriction during Rest Periods of High-Intensity Interval Training Enhances Endurance Performance: A Randomized Placebo-Controlled Study.

Abstract

This study investigated the effects of incorporating blood flow restriction (BFR) during rest periods between sets of high-intensity interval training (HIIT) on aerobic, sprint, and muscular performance in recreationally active participants. Forty healthy males (28.7 ± 6.0 yr) were pair matched and randomized into either blood flow restriction (BFR + HIIT) or sham (SHAM + HIIT) groups and completed nine sessions of HIIT (three sets, 8 × 30 s cycling at 90%-105% maximal aerobic power (W max ), 30 s active recovery, with 4 min rest between sets) over 3 wk. The BFR + HIIT group had 80% limb occlusion pressure applied for the first 2 min of rest between sets, whereas the SHAM + HIIT group cycled under sham hypoxic conditions. Training variables (power output, heart rate, perceived effort, and pain) were similar between groups. Posttraining, endurance performance significantly improved in BFR + HIIT compared with SHAM + HIIT, indicated by greater increases in W max (+25.6 vs +17.2 W, P = 0.014) and time to exhaustion (+61.7 vs +38.4 s, P = 0.008) during an incremental graded cycling test, and increased mean power output (TT MPO : +20.3 vs +9.3 W, P = 0.017) and reduced time to completion (-79.1 vs -39.3 s, P = 0.014) during a 20 km time trial. Conversely, no differences were found between groups in power outputs assessed by the 30 s cycling sprint test, or in muscular power and strength, as measured by countermovement jump and isometric mid-thigh pull tests. Using BFR during rest periods of HIIT enhances aerobic performance without altering training variables, although it may not provide additional advantages for sprint power or strength development.