How do I merge multiple activities into one?

I have a Keiser M3i bike which is able to export a .tcx file of the activity.

I track my rides on my Epix 2 as well, however I cannot merge the two together.  In order to improve I want to track the cycle variables in conjunction with my Garmin's health in a single activity record.

I'm open to other ways to manage this, but this is the best I've discovered so far.  I've tried adding the bike as a sensor to the Garmin.  The search does not turn up the bike.

Is anyone else using an M3i with Garmin Connect with any success?