For doing bench jumps, place the aerobic step on a firm ground and stand on the right side of the aerobic step in its width side. Hold on to the corners of the aerobic step which are away from you; with elbow locks. Align an erect torso, with wide shoulders; bent your knees in a jumping position and fasten your feet together. Now, for bench jumps, jump from the right side to the left side; making sure that you go as high up in the air as you possibly can. And jump back to the right side. Make sure that your shoulders and arms don't get out of position.