1. Aim for lucky number seven.
 


The next time you're tempted to stay up later than you should, remember how comfy that pillow will feel -- and how good a full night's sleep is for your heart.

In one study, young and middle-age adults who slept 7 hours a night had less calcium in their arteries (an early sign of heart disease) than those who slept 5 hours or less or those who slept 9 hours or more.

The type of shut-eye they got was important, too. Adults who said they got good-quality sleep also had healthier arteries than those who didn't sleep soundly.

If you have trouble falling asleep or staying asleep at night, or if you don't feel refreshed after a full night in bed, talk to your doctor about how healthier sleep habits might improve your slumber.