Start from Blaze - Incorrect distance, start from phone - correct distance

[reefoid]

Recently I noticed that Fitbit was showing incorrect disctances for my exercise.  For instance a ride that I know is 9.4km was showing as 8.4km, a 5km walk was being report as 4.2km.  These are all recorded using connected GPS via the Exercise page on the Blaze.

After a bit of experimentation I've noticed that if I initiate the exercise from my Blaze the distance is nearly always under-calculated.  However, if I initiate the exercise from the Fitbit android app on my phone (so bypassing the Blaze), the distance is nearly always correct.  Using Strava or Google Fit in parallel confirms this.  The route maps generated in all apps are identical, but the distance shown by Fitbit can be under-calculated by as much as 20% but only when the exercise is initiated from the Blaze.

Even more confusingly, I have my Fitbit and Strava accounts linked so exercise is automatically uploaded from Fitbit to Strava.  When these routes are uploaded to Strava, the correct distances are shown in Strava.  The correct distance is also shown if I upload the tcx file from Fitbit and upload to mygpsfiles.com.

For example, this morning I did a bike ride and recorded it using both my Blaze and Strava.  At the end of my ride, Strava showed 9.4km, Fitbit showed 8.4km.  The route maps in both are identical.  Fitbit has just exported the data to Strava and the distance is now shown as 9.4km.

So the error appears to be in the way that Fitbit calculates distance when using connected GPS.

I could probably live with this if there was a way to initiate a bike ride direct from the app, but you only get the option to initiate a run, walk or hike in the Fitbit app.  Why can't I initiate a bike ride from the app?

Any advice appreciated.  Anyone else experiencing this?  

[reefoid]

And just to confirm the issue, here is a screenshot of this morning's ride in Fitbit showing 8.6km distance.

And here is the same data after it has been exported to Strava, showing 9.5km.

So the exact same data, but two different distances.

[AngelaMa]

Hello @reefoid welcome to the Fitbit Community! Sometimes the Blaze looses connection with the phone and this might be why the distance information is not as accurate as using MobileRun on your phone. 

Thanks for participating in the Community, hope to see you around more often! 🙂 

[bbarrera]

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@AngelaFitbit wrote:

Sometimes the Blaze looses connection with the phone and this might be why the distance information is not as accurate as using MobileRun on your phone. 

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@AngelaMa thats been my suspicion, would be good for Fitbit to confirm and go on record that a solution is forthcoming. 

@reefoid you aren't alone, this problem has been reported since the Blaze launched.

Regarding your point that MobileRun only supports Walk, Run and Hike, and why not biking - its a good question. From the day the Blaze was announced, I believe the Blaze should have implemented Connected GPS using MobileRun on the phone (to avoid sending all the GPS data over Bluetooth, and deciding what to do if Bluetooth connection is momentarily interrupted). I'm oversimplifying, but all Fitbit needed to do was a) turn MobileRun into MobileTrack (add biking, skiing, etc), and b) send summary stat updates to Blaze (including final stats at end).

Unfortunately Connected GPS today appears to assume an uninterrupted bluetooth connection, and it doesn't do a good job cleaning up the GPS track if data is missing (bluetooth interrupted) or there are "jumps" in location (phone momentarily loses GPS lock, and the location jumps hundreds or thousands of feet). Its a lot easier to cleanup GPS tracks on the phone because of all the processing power. 

[Ozrod58]

I have the opposite problem - a run that measures 11.6 km on Google Earth and when the run is activated from Fitbit App on my phone measured 12.35 km when activated direct from the Blaze (with GPS available from my phone in my pocket). All I really need to know is if I can correct the distance manually as it also plays havoc with my VO2 max estimate.  Thanks Fitbitters!!

[lorielle_48]

My Blaze was recording distance and steps accurately until recently. I walk/run the same track and suddenly it's almost 1/2 mile shorter than ir used to be. Im on the treadmill right now and the step count is off by over 1,000 steps and the distance is off by over half a mike. After reading this post, I now suspect that this problem started soon after I started using Bluetooth headphones. I will test this theory tomorrow. However, FitBit's response above is weak! Can't you attempt to fix the problem since so many users have brought it to your attention?

[AlejandraFitbit]

It's great to see you around @lorielle_48. Fitbit trackers can potentially miss steps while you're walking on a treadmill at very low speed. Are you holding the treadmill's bar while being on it? If you are, I recommend not doing this to have a better accuracy. 

Also, you can restart your tracker and take a look at this post where you will be able to see some tips to make your Blaze more accurate. Now, if you think that your device stills being inaccurate, feel free to provide me with some photos of your information.

See you later. 

[Rich_Laue]

@lorielle_48 is the track an indoor or outdoor track? Is the connected GPS being used or not? Without GPS and on the treadmill the tracker uses tye stride setting fo distance.

[lorielle_48]

It's not just on the treadmill it's also at my local walking track that I know is a little over 3 miles and used to track that but, now says it's 2.33. I use GPS every time.

Tried not using my Bluetooth headphones but it didn't work. If I initiate exercise from the app it works properly. However, this is extremely inconvenient and defeats the purpose of having a FitBit.

Sent from my iPhone