Antioxidants Do Not Prevent Postexercise Peroxidation and May Delay Muscle Recovery

Abstract

TEIXEIRA, V. H., H. F. VALENTE, S. I. CASAL, A. F. MARQUES, and P. A. MOREIRA. Antioxidants Do Not Prevent Postexercise Peroxidation and May Delay Muscle Recovery. Med. Sci. Sports Exerc., Vol. 41, No. 9 pp. 1752-1760, 2009. Purpose: This study aimed to determine the effects of 4 wk of antioxidants (AOX) supplementation on exercise-induced lipid peroxidation, muscle damage, and inflammation in kayakers. Methods: Subjects (n = 20) were randomly assigned to receive a placebo (PLA) or an AOX capsule (AOX; 272 mg of alpha-tocopherol, 400 mg of vitamin C, 30 mg of beta-carotene, 2 mg of lutein, 400 mu g of selenium, 30 mg of zinc, and 600 mg of magnesium). Blood samples were collected at rest and 15 min after a 1000-m kayak race, both before and after the supplementation period, for analysis of a-tocopherol, a-carotene, beta-carotene, lycopene, lutein plus zeaxanthin, vitamin C, uric acid, total AOX status (TAS), thiobarbituric reactive acid substances (TBARS) and interleukin-6 (IL-6) levels, and creatine kinase (CK), superoxide dismutase (SOD), glutathione reductase (Gr), and glutathione peroxidase (GPx) activities. Results: With supplementation, plasma a-tocopherol (P = 0.003) and beta-carotene (P = 0.007) augmented significantly in the AOX group. IL-6 (exercise, P = 0.039), TBARS (exercise, P < 0.001), and uric acid (exercise, P = 0.032) increased significantly in response to the exercise regardless of treatment group. Cortisol level raised more from pre- to postsupplementation period in the PLA group (time x supplementation, P = 0.002). Although TAS declined after exercise before intervention, it increased above preexercise values after the 4-wk period in the AOX group (supplementation x time x exercise, P = 0.034). CK increased after exercise in both groups (exercise effect, P < 0.001) and decreased from week 0 to week 4 more markedly in the PLA group (supplementation x time, P = 0.049). Conclusions: AOX supplementation does not offer protection against exercise-induced lipid peroxidation and inflammation and may hinder the recovery of muscle damage.