Sedentary lifestyle is frequent in hemodialysis patients whose physical capabilities are largely reduced when compared with healthy subjects, and evidence exists that sedentary dialysis patients are at higher risk of death as compared to non-sedentary ones. Dialysis patients may suffer from cardiovascular disease, diabetes, malnutrition, depression, which limits their exercise capacity; conversely, regular physical exercise may favor rehabilitation and correction of several cardiovascular, metabolic and nutritional abnormalities. Many observational, population-based studies show that the level of physical activity is related to quality of life and nutritional status, as well as to the survival probability. Intervention studies are instead lacking; a randomized controlled multicenter trial is in progress in Italy to assess the effect of home-based exercise programs on survival and hospitalization rate in stable dialysis patients. Implementation of physical activity should be one of the goals of dialysis care management, but several barriers prevent a widespread implementation of physical exercise programs in the dialysis units. A lack of patients' or care-givers' motivation or willingness, and structural or functional resources are the most frequent obstacles to exercise implementation. Since the hemodialysis population is quite heterogeneous for physical abilities and comorbidities, exercise in not for everyone and individual prescription is required for a correct and safe implementation of physical activity.