Different heart rates using two fitbits at the same time

[Damc81]

I have a blaze and my girlfriend has a charge 2 and when either of us wear both at the same time they have different heart rates, why would this be? Are they setup to an individual person? I'm concerned as I'm not sure my blazes heart rate is accurate , thank you for any help

[FerdinandFitbit]

Hi there @Damc81. Great to see you in the Community Forums! 🙂

When it comes to heart rate readings, each tracker is set with the personal information of each person, that's why you're required to provide your age, height, weight and gender when creating an account as all this information is taken into consideration for your tracker to provide you with the most accurate info. That's why if you use somebody else's tracker, it will not reflect your information accurately and heart rate depends on a lot of factors which vary from person to person.

Hope this makes sense, let me know if you need anything else!

[Damc81]

Thank you very much for your answer, I assumed that was true but just wanted to rule out the possibility that one of our fitbits was defective.

thank you

[Rich_Laue]

Different?  But by how much?

Wearing 2 at the same time, are tyey on opposite arms and relatively in the same location, or next to each other?

Sorry but not enough details to comment on. 

[FerdinandFitbit]

Thanks for getting back @Damc81!

It would also be good to keep in mind what @Rich_Laue says, to see if both of the trackers are located very close to each other for example and in the same wrist.

If you have more questions, let us know!

[Perza]

Sincerely and with all respect to me this does not make sense.

How can the persons profile make any difference to what heart rate the tracker is reading from the wrist?

It starts to feel very much like Fitbit is fiddling the results of simple measurement data based on some other information and algorithms.

[ATeamCoach]

Ummm ... The heart rate should be the actual, current rate that the heart is beating.

I'm curious.... what other factors would Fitbit utilize to determine heart rate?

My wife put on my Charge 5 while wearing her Charge 5 on the other wrist. The heart rates were significantly different for about 5 min, but eventually the rates were the same.

[LZeeW]

Hello @ATeamCoach and welcome to the Community.  My background is physiology with some biomedical engineering tossed in.  I happen to disagree with the moderator’s explanation.  Completely.  Different models have different optical heart rate monitors and they have different accuracy.  The heart rate algorithms are proprietary.  But independent reviewers’ results suggest that Fitbit changes the algorithms with updates.  So it can be difficult to compare one model with another.   It doesn’t surprise me that the same model on different wrists can take some time to settle down.

[Rich_Laue]

Nobody has mentioned how much the heart rates differ by. 

A few beats, really not an issue.