Does a user's age affect their Daily Active Minutes data from fitbit?

[henryla]

Hi there,

I have an app that collects a user's Fitbit Active Minutes (not Active Zone Minutes) and was wondering for the same user, if they change their birthday, does that affect their active minutes data? 

And what happens when a user already have data and changes their birthday and what will happen to the existing data.

Thank you!

[Guy_]

Hi @henryla - changing birthday can affect how active minutes are calculated. Age affects heart rate settings used in the calculation.

It is unlikely to change historic data. One way to test this is to make the change, it can always be put back.

As changing birthday might have to be done in the Google account (also, to keep aligned or even required) it may affect other functions than just Fitbit.

[YachatsMike]

Active Zone Minutes are based on time in HR  zones.  Heart rate zones are based are derived from %HRmax.  If you haven't set your own value, Fitbit uses 220 - age as your default HRmax.  Every year your HRmax calculation drops by a beat.

There are lots of discussions on "better" ways to determine HRmax.  I'll leave that research to you.  You can manually change the value for your HRmax in the Fitbit App.

[henryla]

I see, thank you!

I tested it a bit and it seems like it's changing historic data as well. 

[henryla]

Ahh thank you! I will look into this a bit more.