The role of dietary antioxidants in exercise-induced oxidative stress and athletic performance

Highly active individuals have a higher mortality than their sedentary counterparts; possibly a response to the chronic production of reactive species produced during prolonged moderate to vigorous activity. Habitual consumption of antioxidant-rich foods is associated with reduced risk of disease; however the contribution of dietary antioxidants to the health and performance of active individuals is still debated. Health benefits of fruit and vegetables have been attributed to their antioxidant content. This review looks at balance between reactive species and the maintenance of redox homeostasis by antioxidants. For active individuals‟ dietary sources of antioxidants, their absorption and metabolism are discussed with recognition of the limitations in the methodology of determining oxidative stress and antioxidant status. Although evidence is not convincing, there is some indication that active individuals require higher amounts of antioxidants than sedentary people, and therefore a higher dietary intake. Recommendations cannot be made at this stage, however whole foods provide a range of antioxidant and matrix combinations not available in a single antioxidant nutrient supplement. Reactive Species, Exercise and Oxidative Stress Physical activity and oxidative stress Prolonged moderate to vigorous physical activity is known to have many beneficial effects; however it also increases the production of reactive species. The impact of the reactive species on the health and performance of athletes is still very much debated, and for many years the general consensus was that reactive species contribute to muscle damage, immune dysfunction and fatigue. This indoctrinated view may under rate the important role reactive species play in athletic adaptation to training. Research demonstrates a link between disease risk and regular participation in large volumes of intense exercise for men (Paffenbarger, Hyde, Wing & Hsieh, 1986). During 12 to 16 years of follow-up in the Harvard Alumini Health study death rates declined as energy expended on activity increased from less than 500 to 3500 kcal per week, beyond which rates increased