August 23rd, 2016 | Sleep

Understanding Sleep

Have you ever slept for ten or twelve hours but woken up tired? Or slept for a mere five hours and woken up refreshed? Why does this happen, and how can you improve your sleep quality?

Sleep quality can be at the heart of our mental and physical health - so it s important to understand what makes quality sleep. To start with, sleep can be broken down into rapid eye movement (REM) sleep and non-REM sleep.


During the course of a night, our bodies cycle through these two phases of sleep. In  non-REM (NREM) sleep  your body goes through three stages: first, it falls into a light sleep, then your muscles relax with with the help of some slow-wave brain activity, and finally the body enters deep sleep. Following non-REM sleep, your body enters  REM sleep, where your eyes will move rapidly (thus the name!) and your dreams are most vivid.


In our app, you may have noticed that we break sleep down into  light sleep  and  deep sleepwhen we give you your sleep data each night. What does this mean?

Light Sleep:

We spend the most time in light sleep during the course of each night. We count light sleep as the first two stages of non-REM sleep - so during this time, your brain is still active, but your body is starting to relax. At this point in the sleep cycle, your body will stir.

Deep Sleep:

Deep sleep is the stage of sleep where your brain rests. This usually happens within the first few hours of sleeping, and your body doesn't usually spend much time in deep sleep. Deep sleep can include both non-REM deep sleep (the last phase of sleep) as well as REM sleep. To feel refreshed and well-rested, it s important to receive between an hour and three hours of deep sleep each night. Pay close attention to your deep sleep time when you review your sleep on Amazfit - and work to increase the amount of time spent here!

Amazfit tracks light and deep sleep by the subtle movements that occur through the night. So while true sleep stages are detected by brain wave activity, we do our best to approximate light and deep sleep with the movement in your arms (or neck, if you are using Amazfit as a necklace).

In the course of each sleep cycle, the entire process of going from non-REM sleep to REM sleep stages takes 90 minutes on average. Being interrupted at any point in the middle of a sleep cycle can cause you to wake up feeling tired. This is another reason why you may sometimes wake up after sleeping 8 hours feeling groggy!


As you begin to understand more about sleep, you may wonder how to get high quality sleep each night. For high quality sleep, we recommend you to target between 1 and 3 hours of deep sleep each night. Deep sleep is the key to quality sleep, and we'll follow up in our next sleep post with a few more recommendations on how to reach and maintain deep sleep each night. Lastly, for high quality sleep,  don't hit that snooze button! Hitting snooze often gets you a few more minutes of sleep at the cost of waking up between sleep cycles, making you feel more tired overall.

The amount of time each person needs to sleep to feel well-rested can vary widely. As a starting point, we recommend you to try targeting 7.5 hours of sleep each night - this is the equivalent of five sleep cycles. Some people need less sleep than others - so listen to what your body tells you and adjust your sleep patterns accordingly.

Have you tried adjusting your sleep time and alarms in the morning? How many hours of sleep are you getting each night? Write in the comments below to share what's worked for you.

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Amazfit Team

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