Frailty is a state of vulnerability that involves an increased risk of adverse events in older adults. It is a condition with a complex etiology and pathophysiology. At present, there are functional tools for its assessment that are simple and reliable. Physical inactivity is a major risk factor for sarcopenia, a core aspect of frailty. Currently, multicomponent exercise programs, and especially resistance exercise, are the most relevant interventions to slow down disability and other adverse outcomes. Moreover, these programs are valuable interventions in other frailty domains such as falls, cognitive decline and depression. However, in frail aged patients it is necessary to explore optimal resistance training components and develop specific clinical guides of physical activity for this target population.