The importance of muscle mass, strength, and metabolic function
in the performance of exercise, as well as the activities of
daily living (ADL), has never been questioned. Perhaps less well
recognized, muscle plays a central role in whole-body protein
metabolism, which is particularly important in the response to
stress. Furthermore, abundant evidence points to a key role of
altered muscle metabolism in the genesis, and therefore prevention,
of many common pathologic conditions and chronic diseases.
This review discusses the various roles of muscle metabolism
in health and disease, including consideration of possible
solutions to muscle loss. Particular emphasis will be given to the
notion that increasing protein or amino acid intakes may optimize
muscle strength and metabolism and thereby improve
health.