Abstract

The purpose of this study was to evaluate and compare the effect of nutritional supplementation (arginine/lysine (AL), versus Exceed (EX), versus placebo (PI)) and resistance-training (RT) on changes in body composition, strength and insulin-like growth factor-1 (IGF) levels. The study involved 37 physically active college men, 20-30 yrs, randomly assigned to one of 5 groups: placebo/control (P/C, n=7); P/RT (n=8); AL/C (n=7); AL/RT (n=8); or EX/RT (n=7). An AL supplement at a dosage of 132 mg/kg fat-free body (FFB) or placebo was administered to controls and training groups, whereas the EX/RT group received one to 1 1/2 cans of Exceed daily, adjusted to ensure a one-pound gain in body weight each week. During the 10-week program, exercise subjects participated in a progressive resistance training program stressing all major muscle groups. Significant increases in total strength (bench press + squat + dead lift 1 RMs) after the 10-week intervention were seen in all resistance-trained groups compared to controls, with no apparent advantage provided by nutritional supplementation. Further, while all RT groups significantly increased FFB mass more than non-exercising controls, the EX/RT group significantly increased FFB mass to a greater extent than did the other resistance trained groups. Finally, resting levels of plasma IGF-I were found unchanged in all groups following the 10-week intervention, suggesting no effect of AL supplementation on human growth hormone levels. Verf.-Referat (gekuerzt)