Julgamento: ____________________________________________________________ AGRADECIMENTOS Agradeço à minha família pelo apoio e força em todos os momentos difíceis durante esta jornada até aqui.À minha namorada Mariana e amigos, com os quais compartilhei momentos bons e também vários ruins, e que sempre me deram força nesses momentos.Aos professores da EEFERP-USP, Enrico Fuini Puggina e Hugo Tourinho Filho que, além de muito me ensinarem, foram os responsáveis por me apresentar à este fascinante "mundo" da pós-graduação e da pesquisa científica, há mais de 5 anos.Principalmente o Hugo, que tanto me apoiou e auxiliou desde então, sem ele eu jamais teria chegado aqui.Ao meu orientador, professor Carlos Eduardo Martinelli Jr., por todo o apoio, paciência e auxílio no desenvolvimento não só desta pesquisa, mas no meu crescimento como pós-graduando e pessoa. The GH-IGF system has several anabolic effects and plays an important role in strength gain. Some studies suggest that Zinc, Magnesium and Pyridoxine ("ZMA") supplementation could increase GH/IGF and testosterone levels in young subjects. This hypothetical increase could lead to significant changes in body composition. ZMA is a very popular supplement, easily found in specialty stores, and it is presumed to cause increasing in GH/IGF and testosterone levels. However, studies are divergent regarding its efficacy. Therefore, the present study aimed to verify the effects of physical training associated with 8-week ZMA supplementation on the IGF-1, IGFBP-3 and testosterone levels in young males. Eighteen healthy male amateur football players were included in the study. They were divided into two groups: ZMA (supplemented group) and placebo.IGF-1, IGFBP-3 and testosterone concentrations were higher in the final evaluation (8 weeks) than at the beginning of the study. The increase was similar in the supplemented and in the placebo group. Both groups showed similar changes in anthropometric parameters attesting for lean mass gain and decrease in body fat mass. The findings suggest that extra doses of the micronutrients present in the ZMA do not bring any additional benefits, either in the body composition or in the hormonal levels in subjects under adequate diet.