As far as I know, for some reason there is no way, how to delete sport Aplications which you created by copying built-in sport apps!
When you choose "Remove App", aplication is just hiden under "+ Add" option.
Even if you connect your watch to PC (in USB mode MTP) and in folder GARMIN \ SPORTS delete specific sport application, after you restart a watch, the deleted application is back. Why? It probably could be solved only by factory reset, but it is a step, that I don't want to do because of such trifle.