I've been using this product for over a few weeks now and have to say it's definitely worth the investment if you have not already gotten yourself a stability ball. Between the two, they can achieve similar results. Use this product to build up your core strength and get those wonderful stomach muscles you always wanted. But it won't be easy! This will hurt for beginners, but over time you will start to see results as much as you feel them. Be sure to watch some workout videos in relation to this Ab Wheel to really benefit from performing this type of exercise correctly without straining your arms, neck, and lower back.