For each two players put 5 coloured pawns in a square of about 6x6 meters, distance of your choice, and a pawn in the middle.
Player 1 starts at the center pawn. Player 2 names a color after which player 1 sprints as fast as possible to the pawn and back to the center pawn.1 minute at a time and then change.
Count how many times you hit the center pawn. Winner is the one who does so the most.