Melatonin administrated immediately before an intense exercise reverses oxidative stress, improves immunological defenses and lipid metabolism in football players.

Acute sport exercise leads to a strong stimulation of muscle tissue and a change in the organism energy demands. This study was designed to investigate the effect of oral melatonin supplementation on human physiological functions associated with acute exercise. Immune, endocrine and metabolic parameters were measured in 16 young male football players, who were divided into two groups, an experimental group (supplementation with 6 mg of melatonin administered 30 min prior to exercise) and a control group (placebo without melatonin). They performed a continuous exercise of high intensity (135 beats/min). Samples were collected 30 min before the exercise and 3, 15 and 60 min during the exercise. The results indicated that the acute sport training presented: a) increased lipid peroxidation products (MDA) in both groups, control and experimental, with levels significantly decreased in the group treated with melatonin after 15 and 60 min of high-intensity exercise, b) the total antioxidant activity (TAS) was lower in the control group than in the experimental, the latter showing significant differences at 60 min of high-intensity exercise c) the lipid profile of subjects in the experimental group showed lower triglyceride levels than the control group after 15 and 60 min of high-intensity exercise, d) immunological studies only showed, in the experimental group, an increase in IgA levels at 60 min after the exercise, and finally there were no significant differences between the groups for any of the other variables. In conclusion these results indicated that treatment with melatonin in acute sports exercise reversed oxidative stress, improved defenses and lipid metabolism, which would result in an improvement in fitness.