Background: The purpose of this study was to determine the effects of whey protein supplementation on performance and hormonal changes during an 8-week resistance training program in novice weight trained men.Material/Methods: Forty recreational weight trained men were randomly divided into a whey protein supplementation (WP) group (n=20), and a placebo (PL) group (n=20). Each group was given either whey protein or a placebo in a doubleblind manner to be taken orally for eight weeks (1.8g/kg/day). WP and PL groups performed the same weight training program 3 days, each week for 8 weeks. The training consisted of 3 sets of 8 repetitions, and the initial weight was 80% of the pre-1RM. Subjects were tested for performance and blood hormone concentrations before and after the 8-week period.Results: The WP group achieved greater increases in body weight, explosive muscular power, muscle strength and blood testosterone when compared to the PL group; however, cortisol concentrations were significantly more reduced in WP group when compared to the PL group.Conclusions: It can, therefore, be concluded that within 8 weeks whey protein supplementation was found to increase explosive muscular power, body weight and muscle strength.