Exercise-induced hormesis

The consequences of physical activity on the brain can readily be integrated into a hormetic framework. Whereas low- to moderate-intensity exercise exerts positive effects on the body, excessive exercise can be detrimental for somatic health. Here we review the evidence linking physical activity with cellular and functional modifications in different organ systems, with a focus on the dose-response characteristics of this relationship. Voluntary running and short-term treadmill running within the range of intensities normally experienced during voluntary running both enhance metabolism and preserve function across multiple organ systems. In contrast, running to exhaustion has a negative impact on global functioning. Overall, the effects of exercise clearly depend on the amount and intensity of activity. These effects conform to the biological principle of hormesis.