Sarcopenia as the Biological Substrate of Physical Frailty.

Physical function decreases with aging, which may result in adverse outcomes (eg, disability, loss of independence, institutionalization, death). Physical function impairment is a common trait of frailty and sarcopenia. These two conditions, albeit highly common, have not yet received a unique operational definition, which has impeded their implementation in standard practice. Here, we introduce a conceptual model in which sarcopenia is proposed as the biological substrate and the pathway whereby the consequences of physical frailty develop. This conceptualization may open new venues for the design of interventions against physical frailty and promote the translation of findings to the clinical arena.