The impact of exercise and nutrition in the regulation of skeletal muscle mass
J Physiol 2018 Jul 16. doi:10.1113/JP275443. [Epub ahead of print]
1 Department of Kinesiology, McMaster University, Canada.
2 Center for Human Nutrition, Washington University School of Medicine, St. Louis, MO, USA.
The maintenance of skeletal muscle mass and strength throughout life is a key determinant of human health and well-being. There is a gradual loss of both skeletal muscle mass and strength with aging (a process termed sarcopenia) that increases the risk of functional dependence, morbidity, and mortality. Understanding the factors that regulate the size of human muscle mass, particularly during the later years of life, has therefore become an area of intense scientific inquiry. The amount of muscle mass is determined by coordinated changes in muscle protein synthesis (MPS) and muscle protein breakdown (MPB). In this review, we assess both classical and contemporary work that has examined how resistance exercise and nutrition impact MPS and MPB. Special consideration is given to the role of different sources of dietary protein (food vs. supplements) and non-protein nutrients such as Omega-3 fatty acids in regulating MPS. We also critically evaluate recent studies that have employed novel 'omic' technologies, such as dynamic protein profiling, to probe for changes in rates of MPS and MPB at the individual protein level following exercise. Finally, we provide suggestions for future research that we hope will yield important information for the development of exercise and nutritional strategies to counteract muscle loss in a variety of clinical settings. This article is protected by copyright. All rights reserved.