Mitochondrial dynamics: roles in exercise physiology and muscle mass regulation

How mitochondria alter their morphology to meet cellular demands epitomizes the ‘form follows function’ architectural principle. These remodeling events are collectively termed ‘mitochondrial dynamics’. The influence of mitochondrial dynamics and of the mitochondria-shaping proteins that control it on skeletal muscle physiology has become clearer. Endurance exercise prompts mitochondrial morphological changes that augment the respiratory capacity of the worked muscles. Mechanistically, exercise training increases mitochondrial fusion protein levels in skeletal muscle to promote the development of a hyperfused mitochondrial network that possesses denser cristae. Conversely, disruptions to the mitochondrial network through imbalances in mitochondrial dynamics lead to muscle atrophy. Insight into the connection between mitochondrial morphology and muscle-mass maintenance will help to pinpoint therapeutic targets that can be exploited to counteract sarcopenia and muscle atrophy in pathological conditions.