Everyone loves to sleep. It would be hard for most people to make it through the day without it. However, while you are asleep, your body does not simply take a vacation. Instead, your body cycles through four stages that serve specific purposes to get you ready for your next day’s activities.
When the lights go out, it’s time for your body to get ready for sleep. But you might be surprised to learn that the active cycle of sleep actually starts with stage 1 of slumber. As you pass into this phase, also known as somnolence, various changes occur in your muscles and brain waves begin to slow.
Once you turn out the lights, your body’s sleep cycle is only just beginning. Learn what you need to know about the stages of sleeping.
Sleeping may seem passive, but your body works in four stages while you’re peacefully asleep in your bed. Learn about the different sleep stages and how the normal sleep cycle works.
What Is a Sleep Cycle?
Most of us know we need enough sleep to stay healthy and do our best at work. And the National Sleep Foundation recommends about 7–9 hours of sleep each night for adults. But most people don’t understand how your brain “resets” itself by going through a series of sleep cycles when you go to sleep each night, which was once thought to be just a period of inactivity.
A baby’s sleep cycle lasts about an hour and a half, while a teenager’s takes around ninety minutes to complete. Each of these stages is characterized by different physical and mental states of activity, consciousness, and hormones. Understanding these sleep stages is important because if your sleep cycle is interrupted (such as by an external disturbance such as light, or an internal one like alcohol consumption), it can affect you deeply.
A complete cycle of sleep stages lasts about an hour and forty minutes, but your entire sleep cycle can be as short as a few hours, or extend into several days. When it comes to children, the sleep cycles are much shorter, lasting only a few hours, while for adults the cycles can last up to 2 days.
The first three stages of sleep are classified as non-REM sleep, and the final stage is Rapid Eye Movement (REM) sleep.