Coping with Physical Activity and Inactivity

Abstract

There is an impressive variation in activity and inactivity patterns among animal species, which illustrates the difficulties of generalising findings from one species to another. Oxidative stress appears to be a ubiquitous consequence of physical effort and also a threat for those species that enter cycles of short- or long-term dormant states and arousal. Hormesis may provide an important mechanistic and theoretical framework to examine the response to and the biological effects of physical effort and preparation for arousal from a dormant state. In this chapter, I examine the differing cases where oxidative stress and hormesis have possibly contributed to shape variation in activity patterns and the solutions animals have evolved to combat the damaging consequences of oxidative stress. I also examine the way animals exploit situations causing moderate stress to shape a phenotype that is better able to cope with the challenges of an intense physical effort or that occur when the organism passes from a metabolically depressed dormant state to an active one.