Antioxidants in physical exercise and sports performance

Abstract

Skeletal muscle contraction generates reactive oxygen species (ROS), which are signaling molecules involved in exercise and force generation. Although ROS levels are maintained at physiological levels by endogenous antioxidants, exercise can alter the oxidant-antioxidant balance in contracting muscles. Regular exercise strengthens the antioxidant defense system via ROS-mediated adaptive responses, while strenuous exercise induces ROS accumulation and oxidative stress. Excess ROS level damages intracellular components and impairs muscle function, potentially limiting physical performance. The manipulation of antioxidant status can restore redox homeostasis and reduce exercise-induced oxidative damages. However, the effectiveness of antioxidant supplementation is unclear due to the complicated and multifaceted roles of ROS in both exercise-induced oxidative injuries and adaptation. The intensity, duration, and types of exercise are also likely to contribute to the effect of ROS in exercise. This chapter provides an updated discus-sion on ROS and antioxidants in aerobic and anaerobic exercises as well as their multifaceted effects on oxidative balance and physical performance.