Taking antioxidant supplements to reduce muscles soreness after exercise could have almost no effect, according to a new Cochrane Review
People engaging in intense exercise often take antioxidant supplements, such as vitamin C and/or E or antioxidant-enriched foods, before and after exercise in the anticipation that these will help reduce muscle soreness. In a new review published in the Cochrane Library, researchers looked at the evidence from 50 studies. These all compared high-dose antioxidant supplementation with a placebo and their participants all engaged in strenuous exercise that was sufficient to cause muscle soreness. Of the 1089 participants included in the review, nearly nine out of ten of these were male and most participants were recreationally active or moderately trained.
The researchers found that high dose antioxidant supplementation, thus in excess of the normal recommended daily dose for antioxidants, does not appear to reduce muscle soreness early on after exercise or at one, two, three or four days after exercise. At all times, the slight differences in the average pain scores found for participants taking supplements compared with those taking placebos were smaller than the difference that people would consider important or even notice. Only nine studies reported on adverse effects and only two found adverse effects.
The evidence for muscle soreness is considered to be 'moderate' or 'low' quality. This was mainly because the majority of studies had aspects that could have affected the reliability of their results and in some cases because of variation in the results of the studies.
Dr Mayur Ranchordas, senior lecturer in sport and nutrition and exercise metabolism at Sheffield Hallam said: "Many people take antioxidant supplements or antioxidant-enriched foods before and after exercise in the belief that these will prevent or reduce muscle soreness after exercise.
"Some athletes are strategically taking antioxidant supplements in order to accelerate recovery during periods of intense competition rather than taking them every day. For example, in professional football, when there is a period of fixture congestion, a team may play three matches in an eight day period (e.g. Premier League fixtures Saturday to Saturday separated by a mid-week Champions League fixture), dietary antioxidants could be strategically used to reduce inflammation and muscle soreness. This would allow the players to recovery more quickly in preparation for the next match. In professional cycling, a Tour de France rider may take antioxidant supplements to accelerate recovery after each stage, in order to recover more quickly for the following day's stage.
"Various types of antioxidants supplements could be used to achieve this and some examples include tart cherry juice, blackcurrant nectar and pomegranate juice. Our review found that antioxidant supplementation may very slightly reduce muscle soreness in the first three days after exercise, however, these reductions were so small that they were unlikely to make any difference."
Dr Joseph Costello, senior lecturer in exercise physiology at the University of Portsmouth said: "Delayed-onset muscle soreness, or “DOMS,” affects many people after exercise and can impair future athletic performance. It usually peaks one to four days after exercise. Taking antioxidant supplements is one of the commonest strategies used by people who hope to reduce the risk of DOMS after engaging in strenuous physical activities. The findings from this review indicate that antioxidant supplementation does not appear to reduce muscle soreness at one, two, three or four days after exercise. These findings have important implications for athletes who use, or are considering the use of, antioxidant supplementation."