Think of your daily activities. Which activity is so important you should devote one-third of your time to doing it? Probably the first things that come to mind are working, spending time with your family, or doing leisure activities. But there’s something else you should be doing about one-third of your time—sleeping. Many people view sleep as merely a “down time” when their brains shut off and their bodies rest. People may cut back on sleep, thinking it won’t be a problem, because other responsibilities seem much more important. But research shows that a number of vital tasks carried out during sleep help people stay healthy and function at their best.