High-dose vitamin C supplements diminish the benefits of exercise in athletic training and disease prevention.

Purpose – The purpose of this review is to summarize new research indicating that high-dose supplements of the antioxidant vitamin C can interfere with the benefits of physical exercise for athletic performance and the risk for chronic disease. Design/methodology/approach – This article reviews current original literature on the regulation of human metabolism by oxidants and antioxidants and evaluates the role of exercise and high-dose vitamin C in this context. The presentation in this article aims to be informative and accessible to both experts and non-experts. Findings – The evidence reviewed here indicates that single, high-dose supplements of the antioxidant vitamin C abolish the beneficial effects of athletic training on muscle recovery and strength as well as abolishing the benefits of exercise in lowering the risk for chronic disease. In contrast, an antioxidant-rich diet based on regular foods apparently enhances the benefits of exercise. These findings are consistent with an updated understanding of the critical importance of both oxidants and antioxidants in the regulation of human metabolism. While more research is needed to address the role of timing and level of antioxidant consumption, it is clear that a balance between oxidants and antioxidants is essential. Practical implications – The information presented in this review is important for both athletes and the public at large in their efforts to choose nutrition and exercise regimes appropriate to maximize the outcome of their training efforts and lower their risk for chronic disease. Originality/value – This article provides accessible and comprehensive information to researchers, nutritionists, and consumers interested in optimal nutrition during athletic training and for obtaining the full benefit of physical exercise in lowering the risk for chronic disease. [ABSTRACT FROM AUTHOR]