If you think push-ups are effective, wait until you try them with the added intensity of the Lifeline Power Push Up Plus! It offers 24 different resistance force levels up to a maximum 80 lbs. of resistance force against your body. The Power Push Up Plus strengthens chest, shoulder, back and arm muscles with push-ups, flies, shoulder circles and punches. You can also tone your abdominal muscles, obliques, and lower back with push-up and press workouts.