Exercise-Induced Oxidative Stress: Theory and Practical Implications for Older Adults

Abstract

Exercise has been promoted as an essential component of a healthy lifestyle during aging. However, benefits of exercise may be partially offset by increased oxidative stress associated with higher oxygen consumption during physical activity. In this review, we discuss the significance of exercise-induced oxidative stress in the aging process. Evidence supports the free radical theory, which posits that the extent of oxidative damage (caused by oxygen metabolism) predicts biological aging. Although oxidative stress tends to increase during exercise, a mild increase appears to upregulate antioxidant defenses and, hence, provide health benefits. A similar phenomenon has been depicted by the hormesis theory. However, intense or prolonged bouts of exercise may overwhelm antioxidant capacity and accelerate the aging process, particularly in an older adult. The risk of exercise-induced oxidative damage may also increase when the exercise regimen is irregular or interrupted for several weeks. Practical implications for older adults are discussed.