Investigation of the effects of oral supplementation of arginine in the increase of muscular strength and mass

Abstract

Introduction: Oral administration of arginine has been associated with physical performance improvement due to probable decrease of muscular fatigue derived from the vasodilatation factor of the nitric oxide over the skeletal muscles. Objective: to evaluate the effects of oral administration of L-Arginine during an exercise program with weights. Methods: 20 male individuals, randomly divided in two groups: A and B, were submitted to eight weeks of training with weights (three times per week). Group A used 3 grams of L-Arginine + vitamin C during the eight weeks and group B used only vitamin C (control group). Results: After eight weeks of training, group A presented body weight values and lean mass significantly higher (p < 0.05), body fat percentage significantly lower (p < 0.05), and strength of lower limbs significantly higher (p < 0.05), while group B did not present significant differences for the same period. Conclusion: Oral administration of arginine associated with a training program with weights increased the stimuli of the exercise to the skeletal muscles level, enabling hence, increase of muscular strength and mass.