Exercise-induced oxidative stress: the effects of β-alanine supplementation in women

The purpose of this study was to evaluate the effects of beta-alanine supplementation on markers of oxidative stress. Twenty-four women (age: 21.7 +/- A 2.1 years; VO(2)max: 2.6 +/- A 0.3 l min(-1)) were randomly assigned, in a double-blind fashion, to a beta-alanine (BA, 2 x 800 mg tablets, 3x daily; CarnoSyn(A (R)); n = 13) or placebo (PL, 2 x 800 mg maltodextrin tablets, 3x daily; n = 11) group. A graded oxygen consumption test (VO(2)max) was performed to evaluate VO(2)max, time to exhaustion, ventilatory threshold and establish peak velocity (PV). A 40-min treadmill run was used to induce oxidative stress. Total antioxidant capacity, superoxide dismutase, 8-isoprostane (8ISO) and reduced glutathione were measured. Heart rate and ratings of perceived exertion were recorded during the 40 min run. Separate three- [4 x 2 x 2; acute (base vs. IP vs. 2 vs. 4 h) x chronic (pre- vs. post-) x treatment (BA vs. PL)] and two- [2 x 2; time (pre-supplement vs. post-supplement) x treatment (BA vs. PL)] way ANOVAs were used for analyses. There was a significant increase in VO(2)max (p = 0.009), independent of treatment, with no significant changes in TTE (p = 0.074) or VT (p = 0.344). Ratings of perceived exertion values were significantly improved from pre- to post-supplementation for the BA group only at 40 min (p = 0.02). The ANOVA model demonstrated no significant treatment effects on oxidative stress. The chronic effects of BA supplementation demonstrated little antioxidant potential, in women, and little influence on aerobic performance assessments.