I am trying to merge my TymeWear ventilation data with my normal activity files (outdoor rides, runs, TrainingPeaks virtual etc).
The merge feature in TymeWear doesn’t work. I have spent a week with AI trying to build a tool that does it, with no luck.
In simple terms I just want to append the activity fit file with the ventilation data (developer fields beginning with tyme* from th secondary fit file) where the timestamps match.
Is there a tool anywhere that can do this?
Here you go 
I’m not 100% sure whether the “File Combiner” simply appends files one after another or also merges records that share the same timestamp. I don’t have a file on hand to test it right now, but I’m hoping it can merge overlapping data as well. If anyone’s tried this, please confirm!
Alternative:
This one should combine and merge if the first tool doesn’t.
Neither of these works. At least not the free versions, Goetoes moght if you pay, but also might not.
They just use combine standard fields, not developer fields like TymeWear populates.
Fitfiletools can’t do that. It only appends activities.
Gotoes might be able with the payed version. It depends if the dev fields are correctly parsed. I’ve been doing this for years with Coros run files to merge Garmin AlphaHRV IQ data into them. But some data from the Garmin get’s lost. Gear data on a ride FIT for example is not being written to the merged file.
I have the paid version and willing to try it out for you. PM me the files and I’ll have a go at it.
BTW: this may sound and look simple, but it absolutely isn’t! It’s a nightmare to merge FIT file data, because FIT can store data in numerous ways.
You could try EnDuRA (www.endura.fit). On the analyse a session page select both FIT files when browsing to choose an activity. As long as the timestamps align then you should get a single merged activity. You can then export the CSV (select just the columns you want as there’s a lot of junk in there!) which I think you could import into intervals.
This is what I’m finding!
It may have been misunderstood by replying with Andres’s quote, but the offer to try it out was ment for you…
If it works, you can decide for yourself if if it’s worth the yearly fee.
Thank you, sorry I missed that. I’ll send you the fit files.
The software Fit File Repair Tools (not FitFileTools) will do it. I used to do that all the time on Zwift when I dual recorded so I could have the Garmin metrics from Zwift before Garmin started calculating them from Zwift files.
I use Golden Cheetah (free and open source) to merge rides (loaded via FIT files) and then exported as a (combined) FIT file
Are the dev fields (from IQ extensions) conserved in that export?
It’s been a while since I used Golden Cheetah and the last version I used, did not conserve them.
I just finished creating a Node.js script to merge Intervals Streams.csv with Calibre Bio CSV: https://storage.googleapis.com/intervals-icu-images/attachments/bcb3e5c4-8777-40ff-8b32-df1335c6969c. It’s easily modifiable to process other stream-based CSV files as long as they have time and heart rate fields.
With the new Intervals upload functionality, it just works. Download and upload activity streams CSV - #19 by pepe. David made this easy.
Sorry - I don’t capture any IQ extension fields, so I don’t know if they are conserved now.
Didn’t know GC can do that.
yup - on the “Activity” menu => Combine Activity
GoToes should work according to: https://gotoes.org/stravatoolsforum/viewtopic.php?t=264 /
https://gotoes.org/stravatoolsforum/viewtopic.php?p=515&hilit=rarely#importConnectIQ 
I tried, but Gotoes has a problem with the US formatted numbers from TymeWear. Gotoes expects Euro metric values in the FIT. Comma/dot is causing wrong interpretation.
I’ll point fulmar2 from GoToes to your posting - guess that should be an easy one to fix … 
