Vitamins A, C, and E- Vitamins A, C, and E all have antioxidant properties. Studies have shown that antioxidant supplementation prevents oxidative stress during exercise. However, because exercise increases the body’s natural defenses against oxidative stress, supplementation may attenuate the adaptive, beneficial effects of training. With that said, the majority of research studies on the effects of vitamin supplementation on performance have shown no effect. However, many studies that supplement Vitamin C at greater than 1 g/day more often than not show a negative effect of supplementation on exercise performance.

Key practice applications: It remains controversial whether athletes benefit from consuming antioxidant supplements. Athletes that consume healthy diets with ample fruits and vegetables likely consume enough antioxidants to meet their body’s needs. More research is needed to determine who can benefit from vitamin and antioxidant supplementation and what doses are optimal.