Your sleep cycle includes light, slow-wave, deep, and REM sleep, which repeat throughout the night. To get restful sleep, you need to spend the right amount of time in each stage of the sleep cycle.

Sleeping for 7 to 9 hours at night isn't the only way to catch some z's. Here are four alternative sleep cycles -- and they're pretty obscure. Annie Miller Medical Reviewer Annie Miller is a licensed ...

Ever wonder why some mornings you wake up ready to go, and others you feel like a zombie? The difference often comes down to when you wake up during your sleep cycle, and that’s exactly what a sleep ...