You may have heard sleep described as something of a magic pill for the body. With the right amount, timing, and quality, it can work wonders -- strengthen the immune system, improve blood sugar, even decrease the risk of heart attacks and strokes. Sleep differences have been reported for some time in men and women, but it is not well known whether the characteristics of sleep serve different functions in one gender over the other, especially as it relates to the heart. New research seeks answers.