The one thing I always encourage is to keep active. No matter what age you are there is a sport that will not only help you keep your body fit but also keep your mind active.
When we are young, the sports tend to be more daring. The sports also tend to have a higher body impact such as football, atv racing, or skydiving. Even leisurely sports such as horseback riding is considered a high risk sport.
As we age, golf, hiking, power walking and bowling tend to replace those high energy demanding sports.They keep our interest and get us out of the house. The added bonus is that they also help us socialize, thus keeping our minds active.
No matter what your age, get out, meet people and get active.