Equipment;
Garmin Fenix 3
Polar OH1 HRM

Sport;
Indoor interval pool swimming

Current Results;
The Fenix 3 data provides laps/intervals/stroke rate etc
The Sepearte OH1 provides the HR data (It records as a standalone device)

Target Result;
An easy workflow (online – so no installed programs, I use a locked down laptop when away) to combine the HR data to the FIT file

What I have tried;
I know how to synch the timestamps fairly close of the OH1 and the Fenix3 so that bit is sorted.
I can get close using the installed version (windows) of sportracks which combines the 2 files, the online version doesn’t combine in the same manner.
I have tried various online merge/combine programs (well loads), but I always end up losing at least (and more often most) of the data streams from the swim (laps/lap distance etc.)

Ask;
Does anyone have a proven method of doing this whist retaining all the data streams viewable in strava
Please no guesses, I’m IT savvyish,, just interested in anyone who has done it