Hold one or both tubes securely in both hands from one side. Keep your hands directly in front of your sternum with palms facing downward and hands together. Create tension on the tubes. Pump your hands to create a downward burst towards the ground. As the tubes come back up, pump down again. Keep the rhythm and keep the path straight up and down. Transition your positioning to directly in front of the tubes, then to the opposite side all while keeping the motion in the tubes.