Investigating the effects of resistance training on the functions of GH/IGF1 axis and L-arginine supplementation

Physical activity and diet are the factors that influence the body's structure. The purpose of this study was to compare the effects of four weeks of resistance training, and L-arginine supplement consumption on growth hormone (GH), and Insulin-like growth factor 1 (IGF-1) Axis. Forty amateur male bodybuilders (aged=22.93 +/-3.50yrs., Weight= 70.23 +/- 11.04 Kg), participated in thisstudy. Theywererandomly divided into four equal groups, Resistance (R), L-arginine (A), Resistance with L-arginine (RA), and Control (C). The Rgroup was assigned to a four week resistance training program. three times/week, three sets of tenexercises with 6-10 repetitions, at the 80-95% 1RM(One RepetitionMaximum), with 120 seconds rest between sets), Agroup is consumingl-L-arginine (0.1 g.kg(-1).day(-1)), RA group resistance training with consuming L-L-arginine, andCgroup continued their normal lifestyle without exercise training. GH, IGF1, IGFBP-III plasma levelswere measured before, and after the protocol. One-way ANOVA indicated significant change in GH, IGF, IGFBP-IIIbetween four groups, and Tukey test demonstrated significant increaseGH, IGF1, IGFBP-III plasma levels in R, and RA group. Based upon these findings, we concluded that resistance training at 80-95% 1RM intensity, and resistance training along with oral L-arginine showssignificantly increase secretion of GH, IGF-1, IGFBP-IIIin amateur males, but additionoralL-arginine toexercise programdo not show significant differenceinGH, IGF-1, and IGFBP-III.