The Human Sleep Cycle UnpackedThe typical sleep cycle lasts for 90 minutes. In these 90 minutes, the human body goes through five stages of sleep. If you are a visual learner, check out this helpful graphic on the sleep cycle from Psychology Today. The five stages are:
- Stage 1—Light Sleep: Light sleep lasts for about 5% of the sleep cycle and is when your muscles begin to relax, perhaps with some muscle twitching.
- Stage 2: This stage makes up the majority of your sleep cycle, from 45-55% of that 90 minute cycle. During this time your breathing and your heart rate slow down and your body temperature has a slight decrease as well.
- Stage 3—Deep Sleep: This lasts for just a short amount of time, only 4-6% of the cycle and is when your body begins to generate slow delta waves.
- Stage 4—Very Deep Sleep: Spanning 12-15% of your sleep cycle, your body is producing delta waves. There is very little movement in the body and breathing is rhythmic.
- Stage 5—Rapid Eye Movement: This is the section of your cycle when brainwaves speed up and people have dreams. The cycle lasts for 20-25% of the cycle. The breath is quick and shallow.