Empowering the vulnerable in internal medicine: a narrative review on physical exercise as a tool to tackle frailty.

Frailty is an increasingly recognized issue in internal medicine, which develops as a consequence of age-related decline in multiple physiological systems, underlying a vulnerable state of health due to poor homeostatic resources. Rapid muscle exhaustion, muscle weakness, dynapaenia, and sarcopenia are common features of frail patients. Indeed, frailty is associated with an increased risk of hospitalization and mortality, and it may be reversed through physical activity and other lifestyle interventions, so to prevent the decline of physical and mental functioning. We herein sought to describe in a narrative fashion the current knowledge about frailty and physical exercise, focusing only on original articles in which frailty was detected and quantified according to international, validated scales or other methods. We will finally discuss future perspectives with regard to the applications of physical exercise in the prevention or treatment of frailty.