Brazilian researchers find little benefit in vitamins C and E for sports recovery
They found that, while antioxidant supplementation reduced oxidative stress, it did not exert any ergogenic effect on football performance in the young athletes, particularly related to elevated markers of muscle damage or muscle soreness post-exercise.
The researchers’ objective was to study how supplementation of antioxidant vitamins C and E may affect oxidative stress, delayed-onset muscle soreness, and performance in football players during a three-day recovery period.
Antioxidants have received attention as a nutritional strategy for minimizing the detrimental effects of strenuous exercise-induced oxidative stress in skeletal muscle and other tissues, though scientific consensus about antioxidants’ benefits are still debated.
“Until now, there has been a general inconsistency of outcomes from investigations of the role of antioxidant supplementation in exercise performance, particularly regarding antioxidant vitamins,” the researchers wrote in their report, published in Nutrition.
Not the first study to question antioxidants for sports
They explained that free radicals have been considered harmful to tissues, prompting the use of nutritional antioxidants like vitamins among athletes with the aim of minimizing muscle damage and improving performance.
Despite multiple studies that have linked antioxidant supplementation to sports recovery, this current study was not the first to suggest that antioxidants may have no benefit for recovery in sports nutrition. “There is currently a controversy in the literature about the positive effects of antioxidant supplementation on athletic performance,” the researchers explained.
For example, a 2003 study using vitamin E found that it had no difference in anaerobic performance, speed, or maximal strength versus placebo. A 2007 study also found that a vitamin C and E combination found no significant differences in performance versus placebo.
Researchers from the present study admitted that there were limitations. For one, they looked at plasma markers of oxidative stress, which cannot reflect tissue oxidative stress.
However, they still did not recommend the use of vitamins C and E for sports recovery. “We believe there is no sufficient evidence that supports antioxidant supplementation as ergogenic aid, and vitamin supplementation, especially high dosage, must be avoid by athletes.”
Study details
The study lasted for four weeks. During this time, 21 male football athletes were randomly assigned to two groups, taking either a placebo or the antioxidant supplement (500 mg/d of vitamin C and 400 UI/d of vitamin E) for 15 days.
After the seventh day of supplementation, athletes conducted an exercise-induced oxidative stress test consisting of plyometric jumping and strength resistance sets to exhaustion. Blood samples, performance tests, and delayed-onset muscle soreness questionnaires were determined before the exercise protocols as well as 24, 48, and 72 hours after.
Source: Nutrition
Published online ahead of print,
“Antioxidant vitamin supplementation prevents oxidative stress but does not enhance performance in young football athletes”
Authors: Donizete C. X. de Oliveira, et al.
