Lower back exercise.
- Begin by laying on your stomach on the exercise ball. Anchor your feet against a wall, BOSU, or similar item. Hold the medicine ball to your chest with both hands.
- Using the muscles of the lower back, slowly lift your upper body so that it is in a straight line with your legs. Hold for a few seconds and return to the starting position. Repeat this exercise 15-20 times. Be sure to do this exercise slowly so that you are giving your back muscles a proper workout, rather than just using the momentum from bouncing off the exercise ball.