I am sure this subject has been posted, discussed, and answered before, but I could not find it. I'm sure if the thread exists, someone will point to it, so thank you in advance if you surface that thread. I discussed this with someone from Garmin at EuroBike last year and it was new to him. Yes, I've been mulling this over for some time and am just now finally posting it.
The issue: *all* workouts must be executed from the Fenix to be "counted" in the Fenix's history, odometers, and fitness indicators.
The problem: workouts run or recorded from another device in the Garmin ecosystem, such as an Edge bike computer, or that taps into the ecosystem, such as TrainerRoad run from an iPhone or other devices, are not recognized, or imported, into the Fenix.
Why this matters: by definition, the owner of a Fenix (Fenix 5X for me/us in this forum), is a data monger, or at least interested in data. The failure to incorporate workouts recorded on other devices, such as Garmin's Edge bike computers or TrainerRoad, means the Fenix has incomplete data. This makes the advanced metrics provided by the Fenix, a key value of this wrist-based computer, deficient as data is missing.
Workout around: To keep the Fenix's performance analytics current, or whole, I must record a cycling workout twice: once on the primary device, such as the Edge or TrainerRoad, and synchronously on the Fenix. I then must delete the duplicated workout from Garmin and any other logging system. As Fenix users are probably a bit attentive to their data and resulting trends, this may include platforms like TrainingPeaks and Strava, necessitating deleting duplicate workouts across these other platforms all for the purpose of keeping the Fenix's analytics current.
And yes, this matters only if one wants to refer to the Fenix's performance analytics, which has its limitations. This is, however, interesting and occasionally, if not potentially, useful information. It is far less useful when a theoretical half (for duathletes) or third (for triathletes) of the data is absent.
Perhaps I'm missing something and I'm creating unnecessary work for myself?