"Exercise, exercise, exercise. It's the only wonder drug we have," Leipzig says. Adults who are physically active not only have a lower risk of disease, depression and chronic pain from conditions like arthritis and back pain but are also less vulnerable to dementia than their inactive peers. The government's exercise recommendations for older adults are identical to those for younger ones. Leipzig underscores a point made by other prevention specialists. "It has to be reasonable," she says. "Walking 30 minutes a day, parking farther away at the supermarket — whatever it takes."