Efeito da suplementação aguda de Melatonina em variáveis de desempenho físico em homens fisicamente ativos submetidos ao treino intervalado de alta intensidade: um estudo duplo-cego cruzado

Abstract

Aims: The present study evaluated the acute effect of acute melatonin supplementation (5mg) on cardiometabolic variables. Method: For this purpose, 12 physically active men (22.1 ± 1.3 years; 1.7 ± 01 meters; 74.7 ± 12.1 kg; 24.3 ± 2.7 m/kg2; 17.3 ± 5.2 %F) were measured in a double-blind crossover protocol where participants were measured before, during and after a high-intensity interval training protocol [4 X 4 min at 95% of maximum heart rate (HRmax) with a 3-min interval at 60-70% of HRmax] followed by 30 min of recovery. At rest, the following variables were measured: HR, systolic blood pressure (SBP), diastolic blood pressure (DBP), lactate and maximum oxygen consumption (VO2max). At the end of each stage and interval, the following were measured: VO2, ventilatory equivalent of oxygen (VE/VO2), ventilatory equivalent of carbon dioxide (VE/CO2) and HR. During recovery, VO2, VCO2, respiratory quotient (RQ), resting metabolic rate (RMR), SBP, DBP and HR were measured. Statistical analyses were performed using SPSS version 25 and differences of p≤0.05 were considered significant. Result: The Melatonin condition resulted in higher VO2 in Sprints 1, 2, 3 and 4 (p=0.03), Interval 1 (p=0.025) and all recovery moments (p≤0.046). For VE/VO2, there were differences at all measurement moments except Sprint 1 (p = 0.053). A similar result was observed for VE/VO2, where there was a difference at all moments except Sprint and Interval 1 (p>0.05). At rest, the Melatonin condition showed higher RMR and lower RQ at all measurement times (p≤0.005). There were no differences for SBP, DBP and lactate (p>0.05). Conclusion: acute supplementation with 5 mg of melatonin exerts an ergogenic effect, increasing VO2, VE/VO2 and VE/VCO2 during HIIT, as well as improving RQ, RMR and VO2 for up to 30 minutes after exercise. However, supplementation does not appear to have a significant impact on blood pressure or lactate levels.