Antioxidant vitamin supplementation prevents oxidative stress but does not enhance performance in young football athletes

Abstract

Objectives: The aim of this study was to verify the effects of supplementation with antioxidants (vitamins C and E) on oxidative stress, delayed-onset muscle soreness (DOMS), and performance in football players during a recovery period after an exercise-induced oxidative stress protocol.

Methods: Twenty-one football athletes were randomly assigned to two groups: placebo and antioxidant-supplemented. Supplementation was performed in a double-blind, controlled manner using vitamin C (500 mg/d) and E (400 UI/d) for 15 d. After 7 d of supplementation, athletes were submitted to an exercise-induced oxidative stress protocol consisting of plyometric jumping and strength resistance sets to exhaustion. Blood samples, performance tests, and DOMS were determined before and 24, 48, and 72 h after exercise.

Results: Antioxidant supplementation was continued during the recuperation week and for a total of 15 d. Antioxidant supplementation caused a significant increase in plasma vitamins C and E. The antioxidant supplementation could inhibit oxidative stress characterized by elevated lipid peroxidation markers malondialdehyde and total lipid peroxidation as well as reduced ratio of glutathione to oxidized glutathione promoted by exercise. Antioxidant supplementation, however, did not significantly reduce the plasma creatine kinesis concentration or DOMS during the recovery days. Likewise, supplementation with vitamin C and E did not improve lower body power, agility, or anaerobic power, nor did it provide any indication of faster muscle recovery.

Conclusion: Antioxidant supplementation does not attenuate elevated markers of muscle damage or muscle soreness promoted by acute exercise and do not exert any ergogenic effect on football performance of young athletes, although it reduced oxidative stress.

Keywords: Muscle damage; Muscle soreness; Soccer; Vitamin C; Vitamin E.