Exercise-mediated regulation of mitochondrial dynamics in aging muscle: implications for mitochondrial diseases

The deterioration of mitochondrial function is a hallmark of aging muscle and markedly accelerates the onset and progression of a range of mitochondrial diseases. Symptoms including limited mobility, persistent fatigue, and muscle weakness are often attributed to impaired mitochondrial dynamics, involving key mechanisms such as mitophagy, fusion, and fission. Exercise has been shown to positively influence mitochondrial health by regulating mitochondrial biogenesis, dynamics, and turnover. This review examines the exercise-induced modulation of mitochondrial processes in aging muscle and delineates its prospects as an intervention for managing mitochondrial diseases. We highlight the molecular mechanisms by which exercise orchestrates mitochondrial dynamics, augments organelle function, and triggers mitophagy-all of which are crucial for the preservation of muscle cell homeostasis. Furthermore, we explore how pivotal molecular pathways such as AMPK, PGC-1α, and SIRT1 regulate mitochondrial adaptations to exercise. This review also underscores the therapeutic promise of exercise in attenuating mitochondrial disease progression via enhanced mitochondrial quality control and improved muscle function. By integrating findings from mitochondrial science, gerontology, and exercise physiology, this review positions exercise as a crucial regulator of mitochondrial dynamics and a viable non-pharmacological strategy for maintaining muscle integrity in the contexts of aging and mitochondrial disease.