I dont think that's an option on any device... If you 'pause' the workout you're essentially pausing the activity including the recording of said activity.
When doing a workout with the Wahoo Elemnt, you can pause the workout and your ride will still continue to record in the background (you are just pausing the workout bit). You can also take a step back or move forward on each interval if you want to. I though this was a basic funtion between all headunits that have a workouot mode. It is very handy and with the roads around me I use it a lot. If Garmin cannot do this then I may have to return it. :-(
