2011, Volume 3, Issue 2
The Effects of Whey Protein Supplementation on Performance and Hormonal Adaptations Following Resistance Training in Novice Men
Hamid Arazi1, Mehdi Hakimi1, Kako Hoseini1
1Department of Physical Education and Sport Sciences, University of Guilan
Author for correspondence: Hamid Arazi; Department of Physical Education and Sport Sciences, University of Guilan; email: h_arazi2003[at]yahoo.com
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.
Key words: protein supplementation, resistance training, hormonal changes