Adding data to a file?

Is there a simple way to add data to an existing file? I’ve started wearing a CGM, and I would like to include the data points that are captured by the device during my rides. Aside from manual scans–which are hard to do when riding–the unit records a glucose reading every 15 minutes. I can reasonably figure out the approximate time of the reading during the ride that the data point was recorded. It seems like this was something that was contemplated with an Ambient CO2 data request (Add Ambient CO2 data?) that was being investigated?

If you can get the GCM to talk to your Garmin and store the data as records in the .fit file then it might be possible to get it into I had a look at your most recent ride and didn’t see anything obvious in the .fit file. There were records for SmO2 and THb.