Inconsistent Data When Uploaded From Microsoft Band?

Newbie to Strava, I love the UI and UE, however, I am confused about the data that is uploaded from the Microsoft Health App.  The data is inconsistent with what has been recorded by the Band and shared on the Health App. For example on the last run the data on the Microsoft Health App was 5.02 miles and a time of 45.25 with an Av Pace of 9.01 in Strava it's recorded as 4.9m  and a time of 45.19 and Av Pace of 9.12.  The splits were completely different too. Which information is accurate? Strava or Microsoft Health app?  Many thanks.

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  • Hi Steve,

    I think it's difficult to track down the answer without more information. Does the Microsoft Health band track your runs with GPS or by using the accelerometer? I suspect there is a difference in technology at play here. 

  • I get the same results.. the Band has GPS and is very accurate.. the Band syncs with Microsoft Health app via Bluetooth on your phone and matches the Band data perfectly, that data is then stored in the Microsoft Health Cloud. From there you can auto sync to other sites such as Runkeeper and Strava, Runkeeper reflects what is displayed in Health app but Strava always shows the miles short. I'm guessing its the way Strava is reading the info from Microsoft Health is the issue as Runkeeper is correct.

  • Actually it's not a technology difference... you can download the GPX track provided by Strava for your Microsoft Health-synced run, then re-upload the track to Strava as a separate activity and the pace/distance appears correctly. Strava is doing some kind of post-processing to Microsoft Health gps tracks that is inconsistent with simply uploading the same GPS track as a GPX file. Could someone reply with some information on what kind of processing is being done to MS Health-uploaded data differently from uploading the same GPX file manually? Looks like a bug to me... 

  • The answer by Ben is exactly my findings too.  I've been experimenting with the runs/files.      A run on the MS Band using GPS for say 10K.....shows as 10K on the MS health website.   When it is sent to shows as say 9.1 Km.       Now if you export the run (GPX) file from the file.      Then import the file back into Strava....         the new activity shows as 10Km!!    how messed up is that.     Can Strava comment on who is doing the conversion?     It's very strange as the data MUST all be there correct at some point....but the processing is awry.



  • This is exactly my findings as well. Yesterday, I did a run with my Band, and then my iPhone 6 running the Strava App. Both the band and the App gave me the same splits & distances. When the run was over the information was equal, yet when I sync'd my Band to the Health App, which is then auto-connected to Strava and created a new activity, The "Band" Strava Activity was 13 sec / mile slower than the "iPhone" Strava activity. I did the same things as mentioned by the other posters, to download the GPX file, delete the current activity (because Strava will recognize a duplicated during upload) and then upload that GPX and the pace is much more accurate. 

    I have a Strava Case open.

    Is there a fix for this. The pacing and distance works fine from the other sync'd apps from Microsoft Health (ie, RunKeeper and MapMyFitness) although Strava has a much better interface and I would rather give Strava my money, I just don't want all my workouts to be 10-15 seconds slower per mile!! 

  • I spoke to a Microsoft band support person about this and they state the issue lies in the way Strava process the data. Very annoying considering I've run 3 10k races recently and only get stats and PB notifications for segments up to 5k !

  • I've always had this issue too when tracking a run using my Band which is using GPS. For example a 3 mile run will show up in the Health dashboard as 3 miles, and usually around .1 of a mile less on Strava. Yet when I export the GPS file from Strava and then upload it into Garmin Connect the distance goes back up to 3 miles. I raised this as an issue with Strava support a few months back and sent lots of samples. I was told it was being raised as a bug report but have heard nothing since. The ticket number was  #446918.

  • Any update on this? Exact same issue with Band 2. Strava always slightly off. Other apps sync fine.

  • I just dont think they are going to fix this - which is a shame..... definitely the problem lies with Strava....and how it deals with the band data.       Other apps have all been fine.    Must be something fundamentally difficult to tackle.......but I think they will lose a lot of potential users by not correcting.    I really did want to stick with Strava to log everything in one place :-(

  • Hello - 

    I've done some investigation for you MS band users. 

    I've taken Paul Hardy's most recent 5k run and downloaded the original file that was sent to Strava from Microsoft Health. The format is TCX. At the beginning of the file is summary data, and throughout the file are data points recording the lat/lon, time, and accumulated distance for each point. 

    For example, the summary lists the total distance: 








    However, the very last data point in the file list the distance differently:














    So, here is what I think is happening. 

    When Strava processes the file, it does not simply take the summary data (correct distance) and plug it into the activity page - instead, it parses each data point to make the graphs etc. When it parses each distance point, the total distance for the activity as seen by this data is 4.9km. This is seen by the final data point above that lists the cumulative distance at the final point. 

    Strava has an admin tool where I can override the distance data in a file and recalculate the distance by measuring between the GPS coordinates. If the GPS coordinates are used to calculate distance, the distance totals a correct 5.0km. 

    If Strava were to simply process all MS data using distance calculated by GPS coordinates, then the distance would be correct. However, by default, Strava instead reads the raw distance data in the file. 


    In my opinion, this is problem stems from the file generated by MS - if the file had the correct distance data written into the data points, then this wouldn't be an issue. 

    I don't have a solution for you folks at this time, but I hope to shed some light on the situation and I'll make sure the rest of the Strava team is aware. 

  • Hi Elle,


    Thanks for looking into this further......that is very interesting....   would it explain how/why other apps cope with that file better ?              Also - does seem odd that when you use strava to export the (under distance) file.....then re-import....I've seen the distance correct itself?


    Hope you guys find a solution as it's really annoying to miss-out on 5k, 10k PBs etc....just because it records it as say 4.8 in Strava etc.


    Happy New Year



  • Wow - thanks Elle. 

    Really appreciate you making the effort. (I haven't looked at the data files, but I'm guessing that GPS accuracy and/or augementation by other sensors/pedometers would be my first port of call).

    In short the variances seem small enough to not be a train smash. For sanity's sake it would make sense that Strava and MS Health at least just pick the same metrics for summary displays (regardless of which are actually correct). At least that's my view :-)

    It's weirdly annoying when you run specific distances (like a 5/10k) and you always just just just miss your goal distance/pace :P

    Thanks in advance!

  • Paul, the outcome when exporting the GPX from Strava makes sense to me. This is because I know that we recalculate the distance in the GPX file based on the GPS coordinates, not the original data. 

    In the meantime, I'd recommend this as a possible workaround. It's a little bit of extra work, but until a better solution comes along as least you can get the correct distance up on Strava. 

    Kobus - I think the GPS accuracy is fine - I think how the MS software processes the distance in the file that they send to Strava is where things mess up. This can be a problem with Garmin files too. 

    What I don't know is how the MS band calculates distance and why the total in the last point is different from the summary value. 

  • Cool.  thanks Elle. That makes sense.     I've found it difficult to raise a ticket to Microsoft...... I take it your developers could probably pose the question to MS and see if they can fix/investigate at their end ?

  • After playing with this integration for two weeks the inconsistency is big enough to make it impractical to use. If the pace difference is more than 15s/km then it's impossible to track your own progress. 

    I'll try and sync my Band 2 with RunKeeper. That should at least definitively tell us if the issue is on the Strava or the Microsoft side.

  • Ok, so here are the results from my little experiment. I did one very short bit (200m) and one longer one (4km) and synced the results from MS Health (Band 2) to both Strava and RunKeeper to see where things go awry.

    Microsoft Health (same as on Band 2)

    4.02km 5:50/km

    0.2km 5:32/km

    Synced to:


    3.9km 5:58/km

    0.2km 5:03/km


    4.02km 5:50/km

    0.2km 5:31/km

    I'm not sure if this is correct, but it seems pretty clear that the error is on the Strava side? The short run difference with RunKeeper seems to just be a rounding difference, so that data is correct. Would be great if the Strava guys can fix this import issue - would hate to have to go back to RK :P


  • I raised a separate support request before I found this thread and the issue occurs on both my Microsoft Band 2 and a friends TomTom sports watch so it's definitely a Strava issue and not specific just to Microsoft Band 2.  I hope they fix it soon as we are just comparing and publishing our results on other tools now which means I may as well cancel my Strava premium subscription if this isn't resolved before the renewal. :-(

  • Hi Ellie.  Would you like me to put you in contact with someone at Microsoft in the Band team?  Guessing you might already be speaking to someone but happy to facilitate.

  • So the interesting part is that if you export the GPX of the acticity which came from a band and has the incorrect distance, delete the activity and then manually upload the activity from the Strava created GPX file the distance is now correct........

  • Trying again to add my comment since the first one did not appear :-(

    There is something strange going on since if you export the GPX from an activity synced from the MS Band which is short on total distance, delete the original run and then manually import the GPX you created at the start the distance comes up correctly so I cannot see that it has magically created 200m on the data points so must be to do with the processing routine. 

  • Dear Elle Anderson,

    Just wondering if you had any update to this incredibly simple issue? Would you guys be able to make Strava calculate the distance from the summary data that comes specifically from Microsoft Health at least? Or maybe give users access to the admin tool? I am talking to Microsoft Band developer devbent on reddit about this issue ( and it does not look like they are planning to change the TCX file to Strava. Seeing as Runkeeper and MapMyRun both are able to pull the correct distances from the summary rather the final GPS trackpoint, it doesn't seem to fix on your end.

  • Really good thread here and I appreciate the research done to date.  I am a band 2 user and it is frustrating to lose 0.2 miles with each run I import into strava, especially when I am with my friends and their runs show faster pace.  most users are not going to do the workaround. any way we can get the MS and Strava technical folks together to broker a common format so that I get accurate results?   I can probably get you in touch with the correct MS resource.

  • The big factor here is that Strava is the only service that integrates with Microsoft Health that has this issue. MapMyFitness, Runkeeper, the others - none of them have this issue. It's clearly a Strava problem.

  • Thanks to Jeremy from support for un-deleting this thread.

    Any update guys? This is getting a little ridiculous.

  • Just wondering if there is somebody who cares about this issue ?

  • I don't care anymore, I just use Microsoft Health now as Strata can't be bothered with support...

  • Glad to see the support forums are important for strava ;)

  • Very disappointing to see the lack of progress. Is it really that hard or time consuming to fix? Surely not? I haven't coded for a while but it doesn't seem like it would take much effort to sort this!

  • dear strava support. have you spoken to the team at microsoft? as I stated earlier, the impact is inaccurate results when I upload ms band results into strava. my distances are consistently off by 0.2 miles which totally throw off my average pace and distance. can you just connect with microsoft and agree how to view the data consistently? please?

  • Very annoying issue. Impacting the enjoyment I used to get from Strava.

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