When selecting outdoor workouts, there’s a little button that I can click to push a workout to my Garmin device. This little button sends out a request to convert TrainerRoad’s workout into a format readable by Garmin and then upload it to their website via an api.
Is there anyway somebody can tell me how to get my hands on that file? Or do I just have to figure it out myself?
Out of interest…why?
Your Garmin device is just that, a device, so when you plug it into your computer it will show up as such in Explorer or Finder. Just open up the device, go to your_computer->Garmin->Garmin->workouts and you’ll see a list of FIT files.
You’ll need a utility to read the FIT file as it’s a binary format rather than plain text like GPX files.
I want to make my own graphs 
I can get the json file of my own workout from trainer road after the fact… but the actual workout that gets sent to Garmin itself is what I’m wondering about.
FWIW, Garmin Connect overlays target and actual recorded power. So you already have the graphs if you execute a TR outside workout on a Garmin bike computer.