Narrator: This is Science Today. The National Sleep Foundation recommends that adults need seven to nine hours of sleep per night. But a national poll of women and sleep has found that more than half of the women surveyed are getting fewer than one or two nights of good sleep each week. Study leader, Kathryn Lee, a professor in the School of Nursing at the University of California, San Francisco says sixty-five percent of these women drink caffeinated beverages to cope with the lack of sleep.

Lee: One of the issues is that they take in so much caffeine that helps them get through their fatigue and gives them more energy, but it's a very temporary fix and they end up being very fatigued in the afternoon, after that caffeine's worn off.

Narrator: Lee says rather than reach for a caffeinated beverage during the day to make up for sleep deprivation, go for a walk.

Lee: Being active will help you sleep better at night. Studies have shown that if you have an exercise program you get more deep sleep during the night and feel more rested during the day.

Narrator: For Science Today, I'm Larissa Branin.