Now I'm going to get a bit nerdy and take a deeper dive into sleep architecture - and explore a question that James Skinner posted over on the forum.
To start, I wanted to look at a few case examples of sleep cycles, so I asked some of my friends if I could borrow their (unidentified) data to explore a bit. I went right in and calculated their typical sleep cycle lengths over the course of the night and here's what I found:
Subject A: 80 minutes
Subject B: 88 minutes
Subject C: 105 minutes
Subject D: 130 minutes
Cumulative Average: 100 minutes per cycle
As you can see, there's quite a range here.
In looking at just these four people, average sleep cycles per person range from 85 to 130 minutes, and individual sleep cycles range from 65 to 155 minutes. Also, it looks like sleep cycles start short, get long, and, if you wait long enough, get short again over the course of the night.
So yes, James; it appears that an average of 90 minutes per sleep cycle holds true (and that data collected by Zeo supports this) but we should probably pay more attention to word "average" when we look at our own personal data (as well as remember that very few people are actually "average" :) )
This may not appear to be all that ground-breaking, but that said there may be some potential here for personal and scientific exploration. Some questions swimming in my head are:
What about you? What sort of questions do you have about your sleep and sleep cycle lengths?
Are you someone with textbook perfect "90 minute" cycles or do they vary?
If you haven't calculated your own sleep cycles, I've got a "how to" section here on our Forum; check it out and really see for yourself how long yours are.