Comparison of health readings between AW S11 and FitBit

[OW22]

I recently got the AW S11 in Titanium, 42mm. I've come back to AW. The last one I had was the Series 4, which I still have, and it works fine. For the past 2 years, I've been using the FitBit Charge 4. I usually use mechanical watches, i.e. "Timepieces".

I wore both watches, the S11 and FitBit, last night when sleeping and got very different readings for sleep scores, for instance. Both results yielded an overall rating of "excellent," with the S11 scoring 92 and the Fitbit scoring 93. But the recordings of REM, Deep sleep etc was very different as below. I know these are not iron-clad, medically accurate devices, but it's interesting to see the differences.

Some of the other readings differ as well. The FitBit gives me a resting heart rate of 54, while the S11 says 59. HRV on S11 is 53 and 37 on FitBit. Blood oxygen was the same for both at 97%. Respiratory rates are significantly different, with 12 breaths per minute on the FitBit and only 9.5 on the S11.

On VO2 max, 52 on S11 and 50-54 on FitBit.

I suppose that when you look at it, these watches, at best, provide a rough, overall indication of health and fitness, but are never going to be very accurate in what they report. Where they can be useful is giving you trends where you could spot changes in resting heart rates or HRV, respiratory rates, which might prompt you to go visit your doctor for a chat and maybe some tests to see if there's anything going on.

One area I've found these watches to be interesting is if you're ill with a cold or the flu, etc, you can definitely see the changes on your vitals via the watches. Heart rates go up, HRV comes way down, and respiratory rates go up, and blood oxygen % can come down.

 

[arc of the universe]

thanks for positing this comparison.
the data are interesting.

most health and fitness apps heavily use the data points you mention.
your data: S11 vs. Fitbit
Resting Heart Rate 59 vs 54
Heart Rate Variability 53 vs 37
apps compare these two numbers as you know to try to make an assessment of your fitness.
and in your case, S11 is both times the higher of the two.
however: since often times a ratio is made between the two above data points, in yr case since one of them (S11) is always higher than the other one, i think its likely that an app making use of this data would actually score your fitness the same, no matter if the data was the S11 or the Fitbit, since ratios would be similar.

your two devices' VO2 scores are very similar to either other.
this makes sense! since VO2 is a kind of super data point that can be used even by itself as a general overall fitness indicator. so, as i pointed out above, both watches are close to evaluating you the same fitness level, even if the the RHR and the HRV are different on the two different devices.

the sleep scores are also interesting.
although the different types of sleep are very different between the two, you provided that Fitbit scored you 93 which Fitbit rates as excellent. even though the S11 is recording the amounts of types of sleep differently, i am sure that if i had that data on my iPhone that the S11 recorded, the sleep score would also be listed as Very Good in apps that use the S11 data for sleep (such as Gentler Streak and Athlytic). so the rating for the sleep is also very similar between the Fitbit and the S11.