Sit on floor with legs far apart or sit straddled on bench. Turns torso to one side with reaching hand above other hand, ready to receive ball from behind. Partner stands with medicine ball throwing distance behind slightly over to receiving side.
Partner tosses ball to receiving side. Catch medicine ball and immediately move ball to opposite side by rotating torso. Pull medicine ball beside far hip. Immediately rotate torso back to opposite side and throw ball back to partner. Repeat same sequence. When finished, receive ball from opposite direction and continue.