Manipulating Internal and External Loads During Repeated Cycling Sprints: A Comparison of Continuous and Intermittent Blood Flow Restriction

This study examined the impact of blood flow restriction (BFR) application method (continuous vs. intermittent) during repeated-sprint exercise (RSE) on performance, physiological, and perceptual responses. Twelve adult male semi-professional Australian football players completed 4 RSE sessions (3 x [5 x 5-second maximal sprints:25-second passive recovery], 3-minute rest between the sets) with BFR applied continuously (C-BFR; excluding interset rest periods), intermittently during only sprints (I-BFRWORK), or intraset rest periods (I-BFRREST) or not at all (Non-BFR). An alpha level of p < 0.05 was used to determine significance. Mean power output was greater for Non-BFR ( p < 0.001, d(z) = 1.58 ), I-BFRWORK ( p = 0.002, d(z) = 0.63 ), and I-BFRREST ( p = 0.003, d(z) = 0.69 ) than for C-BFR and for Non-BFR ( p = 0.043, d(z) = 0.55 ) compared with I-BFRREST. Blood lactate concentration ( p = 0.166) did not differ between the conditions. Mean oxygen consumption was higher during Non-BFR ( p < 0.001, d(z) = 1.29 and 2.31; respectively) and I-BFRWORK (p < 0.001, d(z) = 0.74 and 1.63; respectively) than during I-BFRREST and C-BFR and for I-BFRREST ( p = 0.002, d(z) = 0.57) compared with C-BFR. Ratings of perceived exertion were greater for I-BFRREST ( p = 0.042, d(z) = 0.51) and C-BFR ( p = 0.011, d(z) = 0.90) than for Non-BFR and during C-BFR ( p = 0.023, d(z) = 0.54) compared with I-BFRWORK. Applying C-BFR or I-BFRREST reduced mechanical output and cardiorespiratory demands of RSE and were perceived as more difficult. Practitioners should be aware that BFR application method influences internal and external demands during RSE.