I have a fitball that I have used only once. I bought it 2 weeks ago. It was so hard. I couldnt believe it. There was also the component of goodness me i hope i dont bust this plastic thing. But it held me up. Are there benefits to just sitting on the ball and watching tv? I think the ball should really be good for strengthening my back. I have a tendency to slump. I think its from carrying all this weight around and trying to (cover) myself. I need to seriously work on posture.