Autophagy - Autophagy and Exercise

Autophagy and Exercise

Autophagy is essential for basal homeostasis however; it is also extremely important in maintaining muscle homeostasis during physical exercise. Although the molecular level of this research is only partially understood, it is understood in the study of mice that autophagy is important for the ever changing demands in nutritional and energy needs of exercise, particularly through the metabolic pathways of protein catabolism. In a 2012 study conducted by the Tokyo Medical University in Japan, mutant mice with a knock-in mutation of BCL2 phosphorylation sites to produce progeny that showed normal levels of basal autophagy yet were deficient in stress-induced autophagy were tested to challenge this theory. Results showed that when compared to a control group (physiologically normal/unchanged), these mice illustrated a decrease in endurance and altered glucose metabolism during acute exercise.

Another study demonstrated that skeletal muscle fibres of collagen VI in mice showed signs of degeneration due to an insufficiency of autophagy and this lead to an accumulation of damaged mitochondria and excessive apoptosis. Exercise induced autophagy is unsuccessful however; when autophagy was induced post-exercise artificially, the accumulation of damaged organelles in collagen VI fibres was prevented and cellular homeostasis was maintained. Both studies demonstrate that autophagy induction may contribute to the beneficial metabolic effects of exercise and that it is essential in the maintaining muscle homeostasis during exercise, particularly in collagen VI fibres.