Here’s a tool that syncs your Garmin Connect data to Strava.
I know a lot of people still log their data to both sites, because the analysis of aggregated data is perhaps better on Garmin Connect, and of course Strava is all about the social aspect and the leaderboards etc.
You know how computers in “the future” were supposed to free up our leisure time and make us more productive? Well, if you still upload to both GC and/or Strava/Runkeeper, then this app could literally save you 30 seconds each time. Use it wisely!
How about the other way around, i.e. importing Runkeeper data to Garmin Connect? That would suit me.