Understanding and Addressing Muscle Strength, Mass, and Function in Older Persons

In recent decades, advances in geroscience have taught us that what was formerly referred to as “old age” or “natural causes” is often explained by an accumulation of potentially preventable deficits in multiple body systems, a condition that is encapsulated in certain definitions of frailty.1,2 As research on frailty progressed, the role of declining muscle strength and muscle mass emerged as a key factor in frailty-associated functional decline.3–5 Consequently, reduction in muscle mass and performance, along with a concomitant increase in fat-to-muscle ratio—all of which had been previously labeled as “normal aging”—are now seen as important and potentially reversible causes of functional decline among many older adults.