Exercise is the fountain of youth. Evidently being active cuts the risk of premature death by about 50 percent. One recent study showed that aerobic exercise increased brain volume in older adults. A study of sedentary women ages 65 and up showed that those who increased their physical activity to the equivalent of walking  just half a mile a day were half as likely to die over the following six years. I pretty tell all my patients to exercise more. Even people with orthopedic issues can exercise in water.