Efeito agudo do paracetamol na temperatura corporal, amonemia e desempenho em ciclistas durante exercício em ambiente termoneutro

Abstract

Introduction: although there are disagree, it has been suggested that antipyretics can reduce body temperature during exercise in different environment conditions. The aim of this study was to evaluate the acute effect of paracetamol on body temperature, ammonia metabolism and performances after exercise under a low heat stress environment. Methods: eight male endurance-trained cyclists were divided into two groups: paracetamol (PCT) and placebo (PLA) supplementation, double-blind and crossover. Both groups performed a 30 min cycling session followed by a maximum test (TE). Body temperature and blood samples were obtained at rest, during and after exercise. Cognitive-motor tasks were performed before and after the cycling session, and the exhaustion time was used to evaluate physical performance. Results: PLA body temperature increased significantly for moments 30 min and TE (37.5 ± 0.17 ºC and 37.4 ± 0.13 ºC, respectively), but not in PCT group. The blood ammonia, urea and urate concentrations there was no significant difference between the groups. A significant increase in lactate was observed at the TE moment in both groups. There was no significant difference in the exhaustion times between the groups and cognitive-motor tasks after the protocol. Conclusion: PCT (500 mg) delayed the elevation of body temperature during the continuous exercise, but not during the maximal incremental test. However, no effects were observed in plasma ammonia and physical or cognitive-motor performances because of PCT under low heat stress conditions.