I used Cardio or Strength, though Strength these days is a bit more specific in that now assumes you're trying to do sets and will try and guess what movement you're doing and how many reps you've done. If you're patient enough you can make a copy of the Cardio app and rename it to Crossfit (for example) and this description will carry over to Garmin Connect. I say you need to be patient as it's kind of painful entering the description on the watch. I kind of wish you could use the Mobile App for tasks like this.
