Abstract
Physical exercise-mediated production of reactive oxygen species has been shown to cause oxidative stress, particularly in contracting skeletal muscles. Growing evidence indicates that exercise-induced oxidative stress plays an indispensable role in upregulating signaling pathways required to promote not only skeletal muscle, but also whole body adaptation to physical exercise. It is becoming increasingly clear that exercise-related beneficial adaptations are strongly regulated by exercise-induced oxidative stress, consistent with hormesis theory. According to the hormesis hypothesis, exercise-induced mild to moderate oxidative stress through reactive oxygen species generation stimulates favorable exercise-related physiological adaptations. Additionally, repeated exposure to oxidative stress induced by physical training can trigger various hormesis-based adaptations (i.e., hormetic adaptive responses), including activation of antioxidative defense mechanisms. This brief review provides an overview of several conceptual frameworks related to exercise-mediated hormetic adaptive responses rather than a detailed critique of individual reports.
