GPS Tracking with phone not reflecting heart rate zone mapping

[Randquest]

I am using  Samsung S21 Ultra with a Fitbit Inspire 3.  When I use GPS tracking for my walk and afterwards bring up the the excercise details, for heart zones it always indicates "not enough heart rate data available."  The odd thing is it still has activity zone minutes and I can see my daily heart rate measures through the entire period.  When I wear my watch when it is not llinked to phone, I get a nice graph of my heart rate color coded for the zones.  When linked to phone I only get mins and no zone color mapping.

Moderator edit: Subject for clarity.

[LZeeW]

@Randquest   I apologize if I'm misreading your post.  When you start GPS mapping from the Fitbit app, you are using a feature called MobileRun.  Your choices are run, walk, and hike.  This is an older feature and is designed for older model trackers that don't have an Exercise app.  It doesn't give your heart rate data in the details.  You need to use the Exercise app on your Inspire 3 to get the heart rate in your exercise details.

[Randquest]

In the Fitbit app I am clicking on the excercise tile... then tracking icon in upper right that looks like a stopwatch... then you can select run, walk or hike... then select play like arrow to start tracking.  My belief was the phone and fitbit tracker would be linked and be tied into phone GPS.

After excercise, if you click on the excercise tile and then the excercise event, the map comes up.  Across the top you see map, splits, zone min, etc.   Map has choices of default, heart zone and pace.   It is the heart zone that always says not enough data, even though zone minutes will show data and daily heart graph contains heart data during the excercise period.

I think I understand what you are telling me.  My old fitbit I did it this way but for my new Inspire 3, instead of doing from app, you need to do from watch.  I just ran a quick test and it appears to work.  I am curious why doesn't it work also in the same way from app if knows it is connected to a fitbit device?

[LZeeW]

@Randquest   I looked at your public profile and saw that you joined Fitbit in 2017.  Yes, your old Fitbit used to do this!  I used this with my old Charge HR in 2015.  MobileRun changed in 2019.  That's when it stopped showing the heart rate.  I never read a good explanation from Fitbit.

[Randquest]

Thanks for your help!

For others like me transitioning from an old device hopefully Fitbit will consider the app functioning the same whether you trigger from device or app but easy enough to do now I know and can actually see the display... which got really bad on my old Charge 3.

[RodrigoMFitbit · Accepted solution]

@LZeeW Thanks for your input!

@Randquest Nice to see you in the forums again. Thanks for reaching out about the heart rate tracking during a GPS exercise. I do see where you are coming from. However, MobileRun has changed as explained by @LZeeW. You need to start the training directly from your device in order for the heart rate to be shown on the training summary. I had the same experience when the changes took effect. I cannot explain why it no longer works like it used to, but I can confirm it was an intended change. Thanks for your understanding.