We all know that our sleep is core to our health.
This is the time the body and brain recover, process memories, and prepare us for the next day.
There are many articles on the importance of sleep.
And the struggles we have falling asleep.
Many are even tracking sleep via devices like Fitbit, Apple Watch, and Oura Ring.
What I don’t see often is the discussion of sleep cycles.
Understanding these cycles can improve sleep quality and help you wake up feeling more rested.
Sleep cycles average around 90 minutes.
Those earlier in the night can be slightly shorter (70-90 minutes).
Later cycles might stretch closer to 90-120 minutes.
No matter the length, the structure of these cycles is the same.
Light sleep, followed by deep sleep, followed by REM sleep.
Here’s a summary of the sleep cycle stages and how they work:
Light Sleep: This is where you spend most of the night. The first 5-7 minutes is transition between wakefulness and sleep – our muscles start to relax and brain waves begin to slow. During the remaining light sleep, our body temperature drops, heart rate slows, and eye movements stop.
Deep Sleep: Also known as slow-wave sleep, these are the most restorative phases. The body repairs tissues, strengthens the immune system, and releases growth hormones. We’re harder to wake during deep sleep, and it lasts longer in the first part of the night.
REM Sleep (Rapid Eye Movement): The brain becomes more active, dreams occur, and memories are consolidated. REM sleep is crucial for learning and mood regulation. It typically starts about 90 minutes after falling asleep and gets longer as the night progresses.
My Perspective
I read about sleep cycles around 10 years ago. They have provided so much insight into my sleep.
When I wake in the night, I can see that it is roughly at either a 90 minute or 3-hour mark.
I rarely sleep for three consecutive cycles.
Watching the patterns over the years, I know that my ideal night is 5 cycles – 7.5 hours of sleep.
This insight combined with data from my fitness tracker has really improved my sleep.
Your Turn
Do you track your sleep?
Were you aware of sleep cycles?
How does an understanding of these rhythms change your perspective about your nightly sleep?