Up until age 65, the most important factor in living a healthy life is your genes. But after 65, you’re on your own. According to Laura Carstensen, the Director of the Stanford Center on Longevity, “After that [65], it’s predominantly about lifestyle. Exercise and nutrition become much more important.”

Keeping your body fit not only helps your mobility, but also keeps your mind sharp. Many try to fight off dementia by playing mental games and puzzles. And though they can help, Alzheimer’s Association board member Peggye Dilworth-Anderson says a better investment might be “a good pair of walking shoes.”

A study by the University of Pittsburgh showed that elderly adults who walked between 6 and 9 miles a week were less likely to have cognitive decline. The other good news is that exercise can also improve your social life. In fact, some of the most popular exercises among the elderly are those that involve social interactions. For example, one might join a walking group, play golf, or go out dancing.

Even active video games like Wii Sports can help. In the UK, Barchester Care Homes recently added Wii consoles to their facilities, allowing residents to exercise their arms and improve their hand-eye coordination by playing fun games.

However you choose to go about it, staying fit will help both your body and mind. Have fun!