The gym ball is so versatile it can be used to help someone who is just starting out in the gym as a beginner. For the more advanced sporters it can help by adding an extra level of instability, increasing the challenge of their workouts in a new and potentially unfamiliar way. The great thing about working on balance and stability is that you don't have to do advanced or intense exercises to improve. In fact, one simple tool, an exercise ball, can help you work all of these areas with a variety of simple, easy to follow exercises. Exercise balls -- also known as physioballs, Swiss balls, or fit balls -- are large, vinyl balls you can use to strengthen and stretch your body, improving core stability and balance. When used correctly, these simple spheres can help build a stronger, leaner and more resilient body. The exercises in this app help work on all areas of your body while allowing you to get familiar with the unstable surface of the ball. This is perfect as a beginner if you haven't had much experience using an exercise ball and want a gentle way to work your body.