Physical fragility is defined as “a medical syndrome with multiple causes and factors that contribute to its development and that is characterized by decreased strength and resistance as well as reduced physiological functioning, which increase an individual’s vulnerability to functional dependence or death.” Different multi-systemic pathophysiological processes are involved in the pathogenesis of frailty syndrome, one of the most important being the loss of muscle mass associated with aging or sarcopenia. Several studies have demonstrated that physical frailty increases with age. Physical exercise is the best form of intervention for preventing and treating frailty. In older adults with chronic illnesses, identifying frailty is very important for decision-making, individualizing management, and considering their values and care preferences.