Muscle Oxygenation and Autonomic Recovery After Repeated Sprint in Competitive Soccer Players

This study evaluates the acute and short-term recovery responses to repeated sprint exercise in competitive male soccer players. Forty-eight licensed male soccer players complete an 8 × 30 m repeated sprint protocol under field conditions, with 25 seconds of active recovery between sprints. The study examines several aspects of recovery. Muscle oxygenation is assessed using portable near-infrared spectroscopy sensors placed on the vastus lateralis and biceps femoris muscles. Cardiac autonomic recovery is evaluated using heart rate variability measurements obtained at baseline, 5 minutes, 30 minutes, and 24 hours after the repeated sprint protocol. Countermovement jump performance is measured before the protocol, 10 minutes after the protocol, and 24 hours later. Sprint performance, blood lactate concentration, and perceived exertion are also recorded to characterize the physiological and performance demands of the repeated sprint protocol. The study aims to determine how muscle oxygenation, cardiac autonomic recovery, and neuromuscular performance change during the recovery period following repeated sprint exercise and whether these recovery indicators are associated with repeated sprint performance.