It's the night before the big game, the big race or some other big event, so you want to be well rested. But now it's 3 in the morning and you're watching the glowing clock. What to do? First, stop fighting sleep. Sleep comes in on quiet cat feet. Calming your mind needs practice. Here's the science:

Training your mind for sleep is a lot like training your body to build more strength. The brain doesn't build bigger muscle fibers, but it does build more brain cells. Just as an athletic movement has to be stored in the muscle memory to be retained, newly learned information has to be stored in the brain memory. That requires new electrical pathways to be built among the brain nerves, as well as the addition of new chemical receptors on millions of brain cells.

Think of your mind as a river flowing past, while you are just watching this flowing river. Don't allow your mind to grasp at any of the thoughts that float in this river. Be aware of those thoughts, but let them flow by. After a few tries, you'll find that this mind-calming exercise relaxes the attention you were paying to extraneous things, and the natural physical relaxation works to make you drowsy. Now you are welcoming sleep, not fighting it.


Exercise may help prevent dementia

A new study released by the American Heart Association (AHA) found that regular physical activity could help older people lower their chances of developing dementia. The study found that those who engaged in moderate exercise for 30 minutes at least three times a week reduced their risk of developing vascular-related dementia by 40 percent and cognitive impairment of any kind by 60 percent.

Dr. Ana Verdelho, lead author of the study, says that exercise "is particularly important for people with vascular risk factors such as hypertension, stroke or diabetes." The AHA recommends 150 minutes of moderate exercise or 75 minutes of vigorous exercise per week to reap the benefits of physical activity.