Incorrect GPS distance tracking

[SunsetRunner]

Having had my Charge 3 since Jan 19 and had no major issues, the last few days the GPS seems way off with the distance of my runs being under-recorded by about 20%. Seems to have coincided with the last update. I'm starting the run on my device rather than my phone (as last summer, the app suddenly stopped recording my heart rate info unless I do it this way), but it always connects without any problem.

Any help appreciated! 

[SunsetRunner]

Ran again today and tracked via my device and via the app. The device tracked 5.87k, the app tracked 6.95k and onthegomap.com logs the route as 7.3k. I'd be happy just tracking my runs via the app, but I can't get heart rate data this way anymore... Any suggestions welcome! 

[azwxguy]

Are your distances in km (kilometers)? Do you run with your phone/GPS on an armband? Do you check the recorded route on your phone after exercise is complete?

[SunsetRunner]

Hi!

Yes, all recorded in km. I have my phone (used for GPS) in my waistband and the route records OK, but seems to calculate the distance incorrectly. On the mapped route, it also shows big stretches of the route as being at a really slow pace (79 minutes/km! I'm slow, but not that slow!). 

[Bambalina]

I reported this to Fitbit back in September last year, I had no previous problems with my then charge 2 recording distance, this then changed after an update and it wasn't just a little bit off it was way off, measuring a 5k run at only 3k etc. I found that Fitbit were not very helpful and blamed it on various different circumstances, the area was too built up, poor GPS signal etc, etc... Even though the Strava app on my phone was able to record the distance with no problems and I was also running the same route each time (my local Parkrun) which i did explain to Fitbit at the time. I managed to kind of sort it by manually adjusting my stride length for both walking and running even though there hadn't previously been a problem.

My Husband bought me a charge 3 for Christmas, once again I am having the same issue measuring only 3k for a 5k run, but this time manually adjusting my stride length has not worked. I have fallen out of love with my Fitbit. Sorry that I can't be of any help.

[azwxguy]

Have you tried GPS tracking of another exercise, say a walk around the block. Then compare your measurements to see if the inaccuracies persist. It could be a setting on your phone also. Depending on phone (Apple, Android, different operating system builds) there may be an accuracy setting that might help. I use my Fitbit to GPS track bicycling and walking and I have noticed an improvement in map tracking and also distances over time. I have not compared any of these measurements with another device or app though. I am careful to suggest, as I really don't know for certain, but perhaps all of these separate tracking devices running on the same phone, using the same GPS source, can interfere with each other? Just a thought. Maybe borrow someone else's phone and get an independent measurement. It's odd that large, low complexity portions of the mapped route are so far off.