Fig. 9.

Effect of PGC1α on chronic systemic inflammation. Physical activity determines the amount of PGC1α in skeletal muscle: the more activity, the more PGC1α. PGC1 α, in turn, controls the adaptation of muscle fibers to exercise and confers several benefits. Consequently, a reduction in systemic inflammation is observed in individuals who exercise, particularly in those who engage in chronic exercise. By contrast, inactivity, and thus small amounts of PGC1α in skeletal muscle, results in a chronic systemic inflammatory state, which has serious pathological consequences. This inactivity-driven systemic inflammation is further exacerbated by obesity (not shown). FOXO3, forkhead box O3; ROS, reactive oxygen species. (Nature 2008;454:463–9. With permission).