Exercise is important for everyo

For adults, the recommended time for exercise stays the same. Adults need at least 2½ to 5 hours of moderate-intensity or 1 ¼ to 2 ½ hours of vigorous activity a week. At least two days a week, adults should include muscle-strengthening exercise like push-ups or lifting weights.

There is one key change, though. It used to be thought that aerobic activity had to be done for at least 10 minutes. Now even short times are known to help. Even a single, short time of activity gives short-term benefits such as lowering blood pressure, reducing anxiety and improving sleep.

The advice is similar for older adults. Older adults should also do things that promote balance, such as leg raises, to help avoid falls.

When brains are young, "it's the best opportunity" to set health habits that last.