Interventional strategies to combat muscle disuse atrophy in humans: focus on neuromuscular electrical stimulation and dietary protein

Numerous situations, such as the recovery from illness or rehabilitation after injury, necessitate a period of muscle disuse in otherwise healthy individuals. Even a few days of immobilization or bed rest can lead to substantial loss of skeletal muscle tissue and compromise metabolic health. The decline in muscle mass is attributed largely to a decline in postabsorptive and postprandial muscle protein synthesis rates. Reintroduction of some level of muscle contraction by the application of neuromuscular electrical stimulation (NMES) can augment both postabsorptive and postprandial muscle protein synthesis rates and, as such, prevent or attenuate muscle loss during short-term disuse in various clinical populations. Whereas maintenance of habitual dietary protein consumption is a prerequisite for muscle mass maintenance, supplementing dietary protein above habitual intake levels does not prevent muscle loss during disuse in otherwise healthy humans. Combining the anabolic properties of physical activity (or surrogates) with appropriate nutritional support likely further increases the capacity to preserve skeletal muscle mass during a period of disuse. Therefore, effective interventional strategies to prevent or alleviate muscle disuse atrophy should include both exercise (mimetics) and appropriate nutritional support.