Role of exercise in age-related sarcopenia

Sarcopenia is an age-associated decline of skeletal muscle mass and function and is known to lead to frailty, cachexia, osteoporosis, meta-bolic syndromes, and death. Notwithstanding the increasing incidence of sarcopenia, the molecular and cellular mechanisms driving age-re-lated sarcopenia are not completely understood. This article reviews current definitions of sarcopenia, its potential mechanisms, and effects of exercise on sarcopenia. The pathogenesis of age-related sarcopenia is multifactorial and includes myostatin, inflammatory cytokines, and mitochondria-derived problems. Especially, age-induced mitochondrial dysfunction triggers the production of reactive oxygen species (ROS) by mitochondria, impedes mitochondrial dynamics, interrupts mitophagy, and leads to mitochondria-mediated apoptosis. Aerobic exercise pro-vides at least a partial solution to sarcopenia as it ameliorates mito-chondria-derived problems, and resistance exercise strengthens mus-cle mass and function. Furthermore, combinations of these exercise types provide the benefits of both. Collectively, this review summarizes potential mechanisms of age-related sarcopenia and emphasizes the use of exercise as a therapeutic strategy, suggesting that combined ex-ercise provides the most beneficial means of combating age-related sarcopenia.