Vitamin E supplements are a prudent part of an endurance athletes' supplement regimen according to a review study published in the journal, Sports Medicine. Endurance exercise is believed to contribute to a higher load of free radicals in the body. Vitamin E, as an antioxidant, limits the damage such free radicals can cause in body tissues, such as exercise-induced muscle cell damage and soreness.
In terms of sports performance, the preponderance of the evidence indicate that "vitamin E supplementation cannot improve physical performance in humans without a vitamin E deficiency at sea level, but may exceptionally improve physical performance at a high altitude." More research is needed to explore the role of vitamin E for overtraining athletes or athletes with compromised vitamin E status.
The conclusion drawn in this review was that: "Supplementation with 100 to 200 mg of vitamin E daily can be recommended to all endurance athletes to prevent exercise-induced oxidative damage and reap the full health benefits of exercise."