THERABAND Standard Exercise Balls - 30 inStrengthens muscles, improves posture, balance, and core stability, helps prevent back and spine pain Push the limits of your physical fitness by integrating stability exercises into your workout or rehab routine and develop the core muscles for fall prevention Use to exercise abdominals, back, glutes, hips and other muscles, great for rehab regimens and flexibility training THERABAND Standard Exercise Balls are tested up to 600 lbs. of static weight