I see, thanks for sharing. The last things come to my mind I can share with you are the following:
Sleep diary is quite helpful. And best way is to do it the old-fashioned way.
In my case I was writing it down, directly after getting up and later I put it to some excel sheet to calculate my bed time, time asleep and sleep efficiency.
Bedtime, sleep onset time, wake up events, total time awake and when you got up.
Its enough to estimate the times falling asleep and being awake since your feeling is something you trust and will not change a lot over time. Its also enough to estimate in 5 minutes or even 10 mintue steps no need to break it down to single minutes.
Related to time awake: Our brain will tell us only that we slept, when it was ~15 min+
So, if we are still bit restless and moving around. We fall asleep but wake up within that 15 mins time window, the brain will tell you: you did not sleep. If this happens like 5 times in a row, we think we was awake 1h but in reality, we slept like 45 mins.
Let’s talk about wearables.
I am a huge fan of data but its important to understand what data we see and why. Put it in a framework and never rely on absolute numbers but on trends.
My thought: if the tracker measure things wrong, it hopefully does this consistent so if a trend is moving this information is more reliable.
However, for getting an idea how good or bad some specific brand is I suggest this guy: https://www.youtube.com/@TheQuantifiedScientist
Also, they need to calibrate so give it time until you work with the data.
That’s said, if you do a sleep diary, fill this first before your mind get fed with the Data.
Extra:
Of course, I went to the exercise to compare my felt times to the data (Whoop in my case). In over 2 months of collected and compared data I found out an average discrepancy of only 5%. That’s amazing but I saw several nights where the discrepancy was 25%. It’s a mix of over and underestimating.
Like I said, its important to put it in the framework. The discrepancy was about total time awake so the time falling asleep + wake time. Turns out that Whoop was completely underestimating my onset in many cases but overestimating my wake time in the night.
Why is that? Well, the wearables only work with limited options. Movement + HR/HRV. So, laying still not moving triggers the sleep usually quite fast.
Sleep stage differentiation is one of the hardest exercises for wearables. Simple example REM, intense dream, you might move a lot, the wearable thinks you are awake.
Conclusion:
Sleep diary is very helpful to get an overall idea about your sleep. With all nights documented you also will not miss out the good ones. Over time you will get a much better understanding how things really are and not only have the last bad night in your mind.