PERIPHERAL AND CENTRAL DEMANDS OF REPEATED-SPRINT EXERCISE WITH CONTINUOUS BLOOD FLOW RESTRICTION FOR TEAM-SPORT PLAYERS

Abstract

INTRODUCTION & AIMS Team-sport players’ repeated-sprint ability improves following repeated-sprint training with systemic hypoxia (reduced fraction of inspired oxygen) through enhanced metabolic demands compared to sea-level training. Localised hypoxia (i.e., blood flow restriction; BFR) presents a limb-specific alternative strategy, though central and peripheral demands during multiple-set repeated-sprint BFR exercise have not been quantified for team-sport players. Therefore, this study aimed to assess the impact of BFR during repeated-sprint exercise on performance, metabolic, neuromuscular, and perceptual responses for team-sport players. METHODS Twenty-six semi-professional and amateur team-sport players performed cycling repeated-sprint exercise (three sets of five 5-second sprints with 25 seconds of passive recovery) with continuous BFR at 45% arterial occlusion pressure or without. Power output, vastus lateralis muscle oxygenation, and cardiorespiratory responses were continuously monitored. Surface electromyography examined vastus lateralis, biceps femoris, and lateral gastrocnemius activation, and root mean square was calculated over eight consecutive cycle revolutions. Exercise-related sensations and blood lactate concentration were assessed following sets. Linear mixed models compared differences in dependent variable means between conditions and sets or repetitions. RESULTS Mean, peak power output, and oxygen consumption decreased (p < .01) with BFR (-5.0%, -4.5%, and -6.3%, respectively) compared to without. Vastus lateralis tissue saturation index reduced (p < .001) during sprints and recovery periods for BFR (-6.9% and -5.9%, respectively). Electromyography root mean square decreased (p < .01) for biceps femoris and lateral gastrocnemius muscles with BFR (-2.8% and -8.9%, respectively), but remained unchanged for the vastus lateralis. Perceived limb discomfort increased (p < .001) for BFR, though blood lactate concentration and rating of perceived exertion did not differ between conditions (p > .05). CONCLUSION Repeated-sprint exercise with BFR for team-sport players reduced performance and likely increased the physiological and perceptual stimulus for the periphery with greater reliance on anaerobic glycolysis, despite comparable or decreased central demands.