So be sure to rest up and get your ZZZs!
You may think your body just shuts down when you sleep. However, your body goes through an amazing and complex process. As you go through the four stages of sleep each night, your body triggers processes that help you achieve that rested and healthy feeling the next morning. Here's a graphic from the Huffington Post that shows each stage of the sleep cycle and the effects that being in that stage have on your body. For more information on the the cycles and their effects, check out the full article, Your Body Does Incredible Things When You Aren't Awake.