You won't increase muscle mass or strength by sitting on the ball, but that's not its main benefit anyway. The reason to sit on the exercise ball is that it prevents you from sitting in one position for too long. This keeps your muscles from contracting constantly, in a single position, for a long time - which just…

The mayor of Portland will be super disappointed.

I've never done this, but I don't understand why it is necessary to berate people for trying something new in order to improve their lives. Admittedly, this is one of the lazier ways, but until all of our bosses start letting us use treadmills while we work people are going try and squeeze in their exercise while at…