Get into push-up position. Place one hand on top of the BOSU ball and place the other hand directly under the shoulder in a standard push-up position. Lower into pushup position, keeping hips flat and square to the ground. Exhale and push the body up toward starting position. As you push up, step the inside leg (closest to BOSU) out and bring the outside hand (floor position) up onto the BOSU ball, switching the hands from one position to the other bring both feet back together. Lower into pushup position with the new arm on the BOSU ball, alternate each hand with each pushup. Repeat.