Acute acetaminophen ingestion improves the recovery of neuromuscular fatigue following simulated soccer match-play.

Objectives: This study aimed to investigate the impact of acute acetaminophen ingestion on the responses of neuromuscular function, biomarkers of muscle damage, and physical performance during the 72-hour recovery period following simulated soccer match-play.

Design: The study followed a crossover randomized, double-blind, placebo-controlled trial design.

Methods: During the two experimental sessions, thirteen semi-professional male soccer players completed a 90-minute simulated soccer match, 60 min after oral ingestion of 1 g acetaminophen or placebo. Maximal voluntary contraction and twitch responses of the knee extensor muscles, elicited through electrical femoral nerve stimulation, were utilized to evaluate both peripheral fatigue (potentiated twitch force, Q_tw,pot) and central fatigue (voluntary activation). Performance was assessed through countermovement jump and 20 m sprint tests. Creatine kinase and lactate dehydrogenase were also measured.

Results: Smaller reductions were observed in maximal voluntary contraction (-13.3 ± 7.5 % vs. -24.7 ± 11.1 %) and voluntary activation (-3.8 ± 4.4 % vs. -12.9 ± 5.4 %) in the acetaminophen compared to the placebo condition immediately after simulated soccer match-play (p < 0.05). Afterward, these parameters were recovered 24 h earlier in the acetaminophen session compared to the placebo session. Furthermore, the 20 m sprint performance was significantly better throughout the recovery period in the acetaminophen session compared to the placebo session.

Conclusions: The findings of this study showed that acute ingestion of 1 g of acetaminophen (1 h before exercise) attenuated the decrease in maximal voluntary contraction and voluntary activation levels after exercise, as well as improved 20 m sprint performance.