Physical activity (PA), whether structured aerobic or resistance training or incidental physical activity, provides clinical benefits for a wide range of diseases and disabilities, regardless of age. Exercise has accumulated significant evidence as both a preventive and therapeutic approach for chronic conditions of modern living, including cardiovascular disease, type 2 diabetes, stroke, cognitive impairment, osteoarthritis, osteoporosis, and obesity. Healthy older adults—and especially those with chronic illnesses—are ideal candidates for physical exercise interventions aimed at reducing the burden of multimorbidity, disability, and premature mortality. Individualized, multicomponent exercise programs that incorporate resistance training, balance exercises, and gait training may serve as a cornerstone in preventing falls among older adults with physical frailty. Besides being safe for both healthy and physiologically vulnerable, frail older adults, a properly designed exercise program is free of the potential unwanted side effects caused by common medications that are prescribed in patients with chronic multi-morbidity. Dose-response relationships between changes in fitness and better health outcomes have been defined for some, but certainly not for all, diseases and syndromes. Some modalities or doses of exercise that are promoted for older adults (mild calisthenics and slow-paced walking) have little or no discernible effects on physical fitness, but they may yield benefits in other domains. An example of one multicomponent approach is the Vivifrail project described here. The Vivifrail project (an EU-funded project as part of the Erasmus+ program) is a pilot program, consisting of a rapid screening for physical frailty and sarcopenia, that also provides training on how to promote and prescribe physical exercise to older adults to maintain a level of function that attains the highest degree of functional status.