Partner 1 completes 1 round while partner 2 rests. Then partner 2 completes the next round while partner 1 rests. Continue until 20 rnds are done (10 each). A 400m run is done on completion of 20 rnds, time is called once both people have crossed the finish line.
One more thing… partner up with somebody you don't know, it's make a friend day at CFD!