Title: Effects of Arginine Supplementation on Muscle Endurance and Blood Pressure Responses to Resistance Training
Abstract: Dietary supplement companies have claimed that "nitric oxide stimulating" arginine supplements enhance skeletal muscular endurance. PURPOSE: To determine whether an arginine supplement will affect local muscle endurance of the arm and shoulder girdle, or the blood pressure (BP) response to anaerobic exercise. METHODS: Eight trained college-aged males (23.13±4.02 yr) performed two trials of exercise separated by at least one week. Subjects were requested not to perform upper body resistance training within 72 hours of each trial, and lower body training within 48 hours. At four hours prior, and 30 minutes prior to exercise, a serving of an arginine supplement (3700 mg arginine alpha-ketoglutarate/serving) or placebo was administered. Resting BP was assessed pre-exercise after 15 minutes of seated rest, as well as 5 and 10 minutes post exercise. Subjects did not consume food or caloric drinks for 4 hours prior to testing to control for postprandial effects on BP. Three sets each of chin-ups, reverse chin-ups, and push-ups were performed to exhaustion with three minutes of rest between them. RESULTS: Subjects were able to execute fewer reverse chin-ups (6.63±1.41 vs. 7.62±1.85) during Set 2 after receiving the supplement as compared to the placebo (p<0.05). Although there were no other significant within-subjects effects, there were trends (p<0.10) toward lower BP 5 minutes post exercise (116.00±10.95 mm Hg vs. 124.50±5.93 mmHg) and fewer chin-ups during Set 3 (6.00±1.51 vs. 7.00±1.85) in the supplement trial. CONCLUSIONS: Arginine supplementation does not improve muscle endurance or significantly affect the BP response to anaerobic work. Since arginine supplementation may decrease the repetitions performed in a given set of resistanc