Skeletal Muscle Metabolism

Age-related skeletal muscle loss (termed 'sarcopenia') may be partially underpinned by impairments in the muscle response to nutrition. Disuse events (i.e. illness and hospitalization) result in muscle atrophy, through impairments in protein synthesis and, to some degree, protein breakdown. This is particularly relevant given that older adults take ~650 steps/day on hospital wards and have great difficulty recovering muscle mass during rehabilitation training. Inactivity may also impair muscle mitochondrial function. Thus, interventions to protect skeletal muscle during disuse events are of paramount importance. It is difficult to implement dietary strategies to prevent disuse-induced atrophy in the elderly, due to malnutrition. A more feasible approach may be to introduce small nutritional compounds with pharmaceutical properties (termed 'nutraceuticals') to enhance muscle anabolic and attenuate catabolic processes. However, nutritional interventions alone may not completely prevent disuse-induced musculoskeletal deterioration. Resistance exercise can effectively maintain muscle mass and function when implemented during disuse events. Unfortunately, for many older individuals, heavy-load exercise is not feasible or safe during disuse events. Thus, there is a clear need to develop feasible loading interventions to protect muscle mass and function during and following disuse events