Exercise Activity GPS track not exporting fully to strava

[chrisbrand]

I regularly use the Fitbit Sense 2 to log my running, distance, time, heart rate, GPS track.  I have Fitbit synched with Strava, so when the runs are completed, they are shared to Strava.

Recently all of my runs are synched to Strava, with correct distance, time, heart rate, but the map shows that the run ends around 2km after it starts.  When I download the .TCX file from Strava, the LAT/LON values are frozen with every update after the point where the track stops (around 2km).

Interestingly, if i download the file from FITBIT, i see that at the point where the Strava map freezes, the update rate changes from 1 data point per second, to 1 data point every 5 seconds.   Further, if i upload this file to Strava, everything shows correctly.

Questions:

1. Why does my Fitbit change from 1 sample per second to 1 sample every 5 seconds after 2km?

2. Why does the synch process not work, but manually it is fine?

Note, i saw a similar issue on the Strava help page.  They state that Fitbit is switching to A-GPS, where cellular location is assisting the GPS data.  But, Fitbit does not send this in the autosynch file.

Solved: Re: Fitbit to Strava sync looses GPS track informa... - Page 3 - Strava Community Hub

Thanks

[N8teGee]

Hi @chrisbrand.

I can't really answer your question, but my interpretation from what you describe is that it seems the Fitbit is losing GPS signal and then using other means. The Sense 2 has quite poor GPS capabilities (in my opinion down to antenna design). Is it possible to set the watch to use connected GPS exclusively? I assume you will have your phone with you anyway. This will hopefully work around the onboard GPS issues and also the issue of it switching between the two. Then test again to see if it will sync everything correctly to Strava.

[chrisbrand]

These runs should be using the cellphone GPS. I think it is the cellphone that augments the GPS signal with the cellular signal.

Either way, I think the Fitbit should do better here. Most people are using strava and this is not acceptable.
I will buy a garmin watch instead if they can’t figure this out.

[Triletics]

@N8teGee there is a recently introduced bug that exports incomplete routes into Strava. The route is correct in Fitbit (there's a whole route) but not in Strava. I assume it's a Fitbit side issue as I don't experience anything like that with other platforms. Fitbit broke something again 🤷

[chrisbrand]

Exactly.

The point at which the route ends on Strava is the point where Fitbit changes sample rate from 1/sec to 5/sec.  
Fitbit need to send Strava the location information that they provide in their own .tcx file.

[P1NXT]

I have exactly the same issue, Sense with the Fitbit app and Strava. The Fitbit run is clipped, but confusingly, it is not always clipped or the same failure. Strava shows it clipped but doesn't record heart rate.

The first time was July 29th, but July 30th was OK. (not clipped on Strava, heart rate not recorded)

The second time was July 31st (clipped at 1.1km), but August 1st and 2nd were OK.

Next time,August 5th clipped at 2.2km. August 6th 1.3km.

[chrisbrand]

I expect it depends exactly when the phone changes GPS type.

i bet if you run without the phone, or turn Bluetooth off, so it uses the watch GPS…. It will probably not happen.

[Triletics]

@chrisbrand not true. I use Sense which supports only built-in GPS and the issue happens to me as well.