With all the wearable trackers available, chances are you have one that tracks your sleep. Having this information is one thing, but what does it all mean? I’m going to share what the stages of sleep are and what’s happening within each stage.
There are two categories of sleep, Non-REM, and REM sleep. In Non-REM sleep, it breaks down further into three stages that you will cycle through before getting to REM sleep. There will be marked physiological changes in REM sleep, such as increased respiration, increased brain activity, eye movement, and your muscles will relax.
N1 is the first stage of Non-REM sleep, and it is a very light stage of sleep. Have you ever had a time when someone has woken you up, and you swear you weren’t sleeping? You were probably in N1 sleep. N1 sleep is the transition period from being awake to falling asleep. It can last about 5-10 minutes.
Next comes stage N2 (NREM2). Your breathing and heart rate start to slow down, and your muscles begin to relax. You will spend about 50% of the night in N2 sleep. This stage lasts about 30 to 60 minutes.
After that, you will fall into stage N3 (NREM3); this is better known as deep restorative sleep. This stage is when your body repairs muscles, stimulates growth, and boosts immune function. This stage usually lasts between 45-90 minutes and is longer in the 1st half of the night.
The last stage of sleep is REM sleep. REM stands for Rapid Eye Movement and is the stage where dreaming occurs, and your memories are consolidated and stored. The amount of REM sleep increase in length with each cycle.
A full sleep cycle, consisting of all four stages, lasts about 90 minutes and will keep cycling until you wake up. All stages of sleep are essential, and one is not more important than the other.
Remember that sleep is a physiological process and cannot be forced. The best way to ensure a good night’s sleep is to be relaxed enough to let the biological process happen independently. Good sleep has a ripple effect in the body that can help with fat loss, stress reduction, and a healthier immune system.
Nasca, T, M.D. & Goldberg, R, M.D. (n.d.) The importance of sleep and understanding sleep stages. [Web Page]. Retrieved from:https://www.sleephealth.org/sleep-health/importance-of-sleep-understanding-sleep-stages/#:~:text=Stage%20N1%20%28NREM1%29%20sleep%20is%20a%20transition%20period,breathing%20and%20heart%20rate%20will%20begin%20to%20slow.
What are REM and Non REM Sleep? (n.d.) Retrieved July 13, 2019, WebMD:https://www.webmd.com/sleep-disorders/sleep-101
Sleep Basics (n.d.) Retrieved July 13, 2019, Cleveland Clinic: https://my.clevelandclinic.org/health/articles/12148-sleep-basics