Is everyone's sleep cycle 90 minutes long?!
Question:
Is everyone's sleep cycle 90 minutes long?
All my sources say a sleep cycle is about 90 minutes long, but tracking my sleep, I think mine is about 70 minutes long. Is that possible/likely? How universal is this 90 minute sleep cycle thing?
Answers:
No, everyone's sleep cycles aren't 90 minutes long. Usually when people consider the length of a sleep cycle, what they are actually talking about is their REM latency {the time it takes you to reach Rapid Eye Movement stage of sleep from sleep onset (first time you fall asleep)}. The acceptable range is 70-120 minutes. So, yes, it is highly possible/likely. The 90-minute cycle is just a simple average.