My typical setup is to run a workout in Zwift and simultaneously record the HR, Power, Cadence, and Moxy data (SMO2 & THb) on my Garmin. However, the other night my Garmin didn’t pick of the power data from my trainer, but got everything else. Is there a publicly available tool out there that would allow me to merge the power data from the Zwift ride into the Garmin data? I tried GOTOES, but it doesn’t show an option for merging the Moxy data files… Is there maybe some sort of manual work around using excel or something?
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Maybe this online toolbox can help:
https://www.fitfiletools.com/#/top
Pretty sure Golden Cheetah can do this but it’s probably a lot of overload to install it for one time use.
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I’m a using https://www.fitfilerepairtool.info/ It is available but not free if that what you mean by “publicly available”
If it is just for this once off i’ll do it for you since i can’t remember the restrictions on the trial
If you’ve got both the files in fit format download to your pc then you can merge in www.endura.fit
On the activity page browse then select both files and they should be parsed and merged into a single activity. You can then download the csv with all the merged data ( or even save into EnDuRA 
)
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I might take you up on that offer. I’ve tried GOTOES and FitFileTools to no avail, and tried a couple of things to convert to a CSV but no luck with that either. About to try endura…
Seems like it should be such an easy task to copy/paste the power data from the Zwift file into the Garmin file…the two files are probably within 5 seconds of standing and ending from each other.
David has built the functionality to go in and edit the files, but that would be painful to manually type in 2 hours of 1 sec power data…but it’s that functionality that makes me believe this has to be a very easy task.
Okay; I think I have the merged csv file–at least it looks good in excel. How do I now get this back into a FIT file to upload to intervlas.icu, and training peaks? I tried the tools on http://garmin.kiesewetter.nl/, and CSV to GPX Converter Online - MyGeodata Cloud, but neither worked…
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Unfortunately that’s not something I’ve tried to do yet. It appears the original Garmin fit to csv code I use to read fit files has the functionality to convert from csv to fit so should be possible to develop something
It is a 1 min job with the right tool 
Just email them to intervals.icu @ majland.org and I’ll return the merged file tomorrow (just remove the spaces around @ )
/Anders
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Hey Wayde - I know this is an old post, but I wanted to mention that thanks to some people requesting this feature, I have added the ability to merge Moxy data (i.e. Connect IQ data fields) with other GPS files (GPX/TCX/FIT/CSV) to the GOTOES tools. To make it work, you need to upload your FIT file(s), and then on the 2nd page (where you enter the settings), you need to check the “ConnectIQ” checkbox. IF there is any ConnectIQ data in the file, it will be added to the export. Right now, it only supports ConnectIQ “streams” (the kind of data that shows as a graph on Garmin Connect). It does not import single point dta. Hope that is helpful at least a little. Also, if you use the contact form on the GOTOES page, you can send me files and I can either merge stuff for you or maybe add requested features.
Hi Anders— Could you share the right tool? I have ~1000 files from many years ago that I am looking to convert and will script them myself once I find the right tools.
hi everyone. i have a question about fit file repair tool. So when i try to combine a file from garmin and a file from zwift (same activity, but recorded from different devices) i end up with file that has double the time. How do i fix that?? So two files with 1hr activity when combined become a 2hr file. This makes sense, but that’s not what i am trying to do. Is there a way to do a selective merge of the two files (that does not combine the times)? So that i can take the GPS, speed, distance data from Zwift file and overwrite those fields in the Garmin file and still end up with a final file that is 1hr?
Sorry, i am a little new at this. Thanks for your help!
nina
Combine in merge mode, not append mode.
Synchronyze by a field share by the two files like harte rate
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