Continuous blood flow restriction during repeated-sprint exercise increases peripheral but not systemic physiological and perceptual demands

This study examined the impact of continuous blood flow restriction (BFR) during repeated-sprint exercise (RSE) on acute performance, peripheral, systemic physiological, and perceptual responses. In a randomized crossover design, 26 adult male semi-professional and amateur team-sport players completed two RSE sessions (3 sets of 5 × 5-s sprints with 25 s of passive recovery and 3 min of rest) with continuous BFR (45% arterial occlusion; excluding during between-set rest periods) or without (non-BFR). Mean and peak power output were significantly lower (p < 0.001) during BFR compared to non-BFR (d_z = 0.85 and 0.77, respectively). Minimum tissue saturation index during the sprints and rest periods was significantly reduced (p < 0.001) for BFR (d_z = 1.26 and 1.21, respectively). Electromyography root mean square was significantly decreased (p < 0.01) for biceps femoris and lateral gastrocnemius muscles during BFR (d_z = 0.35 and 0.79, respectively), but remained unchanged for the vastus lateralis muscle in both conditions. Oxygen consumption and minute ventilation were significantly reduced (both p < 0.01) for BFR (d_z = 1.46 and 0.43, respectively). Perceived limb discomfort was significantly higher (p < 0.001) for BFR (d_z = 0.78). No differences (p > 0.05) in blood lactate concentration or rating of perceived exertion were observed between conditions. Blood flow-restricted RSE reduced performance and likely increased the physiological and perceptual stimulus for the periphery with greater reliance on anaerobic glycolysis, despite comparable or decreased systemic demands.