I use my watch for all my outdoor activities, but for running on the treadmill I don't use the watch as I find it inaccurate. Instead I use an app which "talks" to the treadmill, records an accurate speed / distance trace (adjusted for a real-world factor so that broadly the pace on the treadmill results in a pace / effort level which I find to be closely related to the outdoor experience) and then outputs a .fit file.
I upload this .fit file to GC and then this cascades the activity properly to other services like Strava etc. All good.
The only two things that don't "work" as I'd like is that the activity doesn't get added to my watch's data in terms of the VO2Max calcs nor the training load.
Is there a way to force this for one, either or both of these things? I don't quite see why VO2Max can't be calculated server-side for an imported .fit file, and certainly don't see why training load doesn't get sync'd across. (That said, I don't pay for the service, so I don't complain too much!)