Corporate wellness insights

Understanding the Sleep Cycle

Posted by Colleen Sideck, MPH, RDN on 12.26.2018

We may not remember what happens when we sleep, but that doesn’t mean our brain and body are taking time off! Sleep is a crucial time for rest and recovery, meaning that the brain and body are actively clearing built up toxins and repairing their tissues. Without restful sleep that takes you through all stages of the sleep cycle, it becomes more difficult for your brain to learn, concentrate, and create new memories.

The body cycles through the stages of sleep multiple times through the night. Each stage in the sleep cycle serves a distinct purpose in helping us maintain a clear mind and healthy body. If our sleep is frequently interrupted or shortened, we may not be cycling through the stages enough for adequate recovery. Read on to learn what happens to the body during each stage of the sleep cycle and how it benefits our health:

Stage 1

This short stage lasts 1 to 7 minutes and happens as we transition from being awake to being asleep. The body starts to relax: our heartbeat, breathing, brain waves and eye movements slow, and our muscles relax. Stage 1 sleep is light, meaning that we can be easily woken and may be somewhat alert.

Stage 2

In this stage, our sleep is also light, and our body relaxes even further. Eye movements stop, and body temperature decreases. Stage 2 sleep lasts 10 to 25 minutes and helps the body progress to deeper, more restorative sleep.

Stage 3

Stage 3 sleep is the first period of deep sleep that we enter during the night. Our body becomes its most relaxed. This stage is when the body repairs its muscles and tissues, restores its energy levels, and promotes cell growth. We need this stage to wake up feeling rested. Typically, stage 3 lasts 20 to 40 minutes.

REM Sleep

Rapid Eye Movement (REM) sleep is when the brain becomes more active. Most memory processing and storage occurs in this stage, which means we incorporate information from the day into our long-term memory. This stage is typically when dreaming occurs, and arm and leg muscles are temporarily paralyzed so that we don’t act out our dreams. Each REM stage can last up to 1 hour, and most adults have five or six REM cycles nightly.

Colleen is a member of the WCS Health Coaching team. As a Registered Dietitian, she is passionate about our team's ability to guide employees towards sustainable, healthy habits that help them lead their fullest life—inside and outside the workplace.