There's a new bold study published in European Journal of Sport Science: Antioxidant Supplementation and Endurance Training: Win or Loss?
We all know that antioxidants can play an important role in our defence against free radicals - those seemingly 'bad guys' that cause all sorts of disease and damage in our bodies. We also know that free radical production is greater during exercise.
Most endurance athletes have thought that it would be wise to take common antioxidant supplements like vitamin C regularly. It's has also become a convenient habit for many to take a multivitamin daily, just in case we might need it.
However this Swiss study questions the wisdom of taking antioxidant supplements during endurance training, because they may generally be quite counterproductive. In other words, taking antioxidants might actually prevent the very results we spend all those hours to train for.
"Could it be that many are unknowingly counteracting training effectiveness through banal practices such as consuming an antioxidant-rich recovery drink after an endurance training session or taking a daily multivitamin?", the study asks.
There is evidence for negative effects of antioxidants for those who wish to improve their performance capacity. Also whenever some muscle injury occurs, vitamins C and E have been shown to delay healing and recovery.
Quite surprisingly, free radicals are now understood to have many positive effects as well. They seem to play a particularly important role for endurance athletes. Free radicals help us achieve various physical fitness adaptations through training.
The practical recommendation for normal endurance training would be to rely on antioxidants found in healthy foods, and avoid artificial supplements unless there is some special situation like a high-altitude training camp or diagnosed deficiency.