What's up with this sleep score?

[Floatious]

Last night, I slept about 4 1/2 hours, woke up for an hour, and fell back asleep for another 2 or so. I checked the app both times I woke up and got the following scores:

What's up with that? I get 2 hours additional sleep, but my time asleep rating does not improve, and my overall sleep score plummets because of the awake time is increased restlessness and awake time vs deep/rem.

Why is this? Is it because I manually adjusted my wake time because the second round of sleep initially showed up as a separate entry without the typical sleep score metrics? Because I guarantee you, I would be an absolute zombie today without the extra 2 hours, yet Fitbit seems to think it made my sleep worse.

[RiekoC]

Hello @Floatious 

Like you, I've also experienced lower sleep scores when I've had to combine 2 separate logs into a single one. 

Your sleep score adjusted after you combined your 2 sleep logs as you noted. Because the sleep score calculates for the entire time for your sleep log, your Deep & REM score dropped as did your Restoration due to the hour you were awake. The most important thing is that you got the additional 2 hours of sleep that you needed and your score stayed in the Fair range. 

It's hard not to stress out when we see our sleep scores aren't as good as we'd like. The score is there to give us some awareness if we are getting enough and good rest to recuperate from our day as well as help with workout planning. 

You might want to check out this page which gives more information about the Fitbit sleep score (<-- click link). 

[JMark235]

Just curious as to what tracker you use, whether you are using the Fitbit premium option and whether you are on an iPhone or Android because the sleep data I see on IOS with a Versa 2 is very different.

In my case, REM and Deep Sleep durations are displayed separately rather than combined, I don't get scores for each of the metrics individually that are used to calculate sleep score and there is no indication of how 'restorative' (the Restoration metric) my sleep was. I'm thinking that the restoration score could help to explain apparent anomalies with my equipment where a longer sleep duration with a lot more REM & Deep Sleep minutes results in a lower score even when the resting heart rate is identical and the sleeping heart rate with the lower score also appears to be below the resting heart an approximately equal amount of time. I say appears because the only way for me to estimate this metric is by looking at the 2 heart rate graphs.

Thanks

[MrBosco]

I think the sleep score function is something that has to be taken with a huge grain of salt.

The day before yesterday I saw my doctor and got both the flu and covid vaccines.  I was also asked to wear a 24hr blood pressure monitor to evaluate my medication.

That night I mild flu-like symptoms from the vaccines - chills, a mild headache and mild muscle pains.  I also had the blood pressure monitor going off every 40 minutes, which is loud and slightly painful when the cuff inflates fully.  I didn't get any real sleep.  At best I dozed, a bit like that time between hitting the snooze button and the alarm going off a second time - nearly asleep but not quite, still aware of sounds but with muddled snoozy thoughts.  My heartrate graph shows that I never reached my true sleeping heart rate.  The results of the BP monitoring confirm that I was never fully asleep, as my BP didn't drop overnight as it should.  I was wrecked tired the next day.

Fitbit tells me I got 7 hours and 45 minutes of sleep that night, with a sleep score of 76.  It further tells me I had two periods of deep sleep with a total time of 1 hour and 46 minutes.  This is ludicrous.  I have no idea how Fitbit calculates the light, REM and deep sleep metrics, but I can confirm that it can't really tell if you're actually, properly asleep in the first place.

[Floatious]

Oops! I should have clarified in my original post: I'm using a Charge 6 on an Android phone with a premium subscription. Hope that helps!

[LZeeW]

@Floatious   It's going to be hard to get a satisfactory answer.  Sleep scores are a proprietary (secret) analysis of quantity and quality.