The Effects of Simultaneous L-arginine Supplementation and Resistance Training on Muscle Strength and Some Blood Fat Profiles and Body Composition in Adolescent Boys

The main objective of this research was to investigate the effects of L-arginine supplementation and resistance training on muscle strength and some blood fat profiles and body composition in adolescent boys. Thirty-six adolescent boys (age: 16.81±1.19 years; BMI: 20.17±4.15 kg/m2) were randomly divided into three groups (experimental groups 1 and 2 as well as a control group). Participants in both experimental groups trained three times a week and performed 3 sets of 8-15 repetitions of resistance exercise with the intensity of 60-75% of one repetition maximum for 8-weeks. The first experimental group took two grams of L-arginine supplements along with performing resistance training, while the second experimental group took the same amount of a placebo (Starch). The participants’ weight, body mass index (BMI), high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol (CT), triglyceride (TG), LDL to HDL ratio (LHR), arm circumference (AC), thigh circumference (ThC), and maximum strength of bench press, back press, barbell press, squat, and leg press were measured at baseline and after eight weeks of exercise. Data were analyzed using mixed ANOVA with Tukey post-hoc (α≤0.05). Significant improvements in the participants’ weight, BMI, chest bench, back press, barbell press, squat, and leg press were observed in both experimental groups (P<0.05). The first experimental group showed significant improvements in LDL, TC, TG, and AC (P<0.05). There was no significant difference in HDL, LHR, and ThC in any groups (P>0.05). Control groups, however, did not show significant difference in any of the parameters (P>0.05). This study showed that eight-weeks of resistance training along with taking L-arginine supplements can positively affect muscle strength and some blood lipid profiles as well as body composition in adolescent boys.