Use the ZoN Balance Ball to add variety to daily workouts while toning and strengthening core muscles. The ZoN Balance Ball provides an effective, low-impact workout that you can do virtually anywhere to develop muscular fitness and improve flexibility, strength and balance, especially in the all-important core area. When training on a round surface, you not only train the primary muscle groups, but also the smaller stabilizing muscles as well. Anti-burst, non-slip material lets you concentrate fully on your workout without worry and cushions the body while performing exercises.