Contents
Intro
Getting a sufficient amount of sleep is important to feel rested and refreshed in the morning. But if you wake up during the wrong part of your sleep cycle, you may feel groggy and sleepy instead of refreshed.
Our brains naturally cycle through 90-minute periods of wakefulness and sleepiness throughout the night. By sleeping in 90-minute cycles, you are allowing your brain to complete all the necessary stages of sleep. This will leave you feeling more alert and rested when you wake up.
There are a few things you can do to make sure you are sleeping in 90-minute cycles. We’ll discuss those techniques, and why sleep cycles are so important in this article.
What happens during the 90-minute sleep cycle?
The first stage of sleep is when you first drift off to sleep. You can easily wake up during this stage. This is followed by a period of light sleep where your body starts to relax more. This is followed by a deeper stage of sleep where your breathing and heart rate slow down. Then you enter the deepest stage, called slow-wave sleep. Your body is at its most relaxed, and your brain waves are slowest. These are all non-REM stages of sleep.
Finally, you enter REM sleep, which is when you dream. Your eyes move rapidly, and your brain activity is greatly increased. The amount of REM sleep you get in each cycle increases throughout the night.
One thing to keep in mind is that 90 minutes is only an average. It’s not a set-in-stone number of minutes for everyone. Your personal sleep cycle may be longer or shorter than average. You can figure this out for yourself through trial & error by noticing how you feel when you wake up and taking note of how long you slept.
Check out our previous article on the stages of sleep for more in-depth information.
What happens if you wake up in the middle of the cycle?
In a perfect world, you would allow yourself to wake up naturally. This means your body reaches the end of a sleep cycle and wakes up before entering another cycle. This isn’t always easy to do. For most of us, we need to use an alarm clock to wake up in time for work or school. Sometimes your alarm clock will wake you up during deep sleep, which is unfortunately not ideal.
If you wake up during a sleep cycle, you may feel disoriented and groggy. You may also have difficulty getting back to sleep. It is best to try and relax and go back to sleep, or get out of bed and do something calming until you feel sleepy again.
How can you make sure you wake up at the end of a sleep cycle?
There are a couple of methods for waking up at the right time, even if you need to use an alarm clock. First is the manual method. Decide what time you need to wake up, then add up the amount of sleep cycles you need. Then work backwards to determine what time you need to go to bed to get your number of sleep cycles. This can be tricky, because the amount of time it takes to fall asleep can vary, but you can get pretty close if you know about how long it takes to fall asleep.
Another option is a sleep cycle phone app. There are numerous apps on the market that will calculate your sleep cycles for you and tell you what time to go to bed. Some of them will also monitor your sleep and wake you up when your sleep is lightest. Other devices like smart watches can perform these functions, too.
How many sleep cycles do you need?
The ideal number of sleep cycles for an adult is 4 to 6. This equals about 6 to 9 hours of sleep. Infants, young children, and teenagers generally need more sleep, and will do better with up to 11 sleep cycles every day. Elderly people can get by with less sleep, so they will fall on the lower end of the 4 to 6 range.
Every person is different. Listen to your body and experiment with the number of sleep cycles you get every night. When it comes to feeling refreshed upon waking, it’s more important to wake up at the end of a cycle, than it is to get 20 or 30 more minutes of sleep if it means you wake up during deep sleep.
