Physioball (swiss ball) Air Capacity...

I purchased my first physioball today so I can do some of the exercises from a book that I purchased recently. However, this is the first swiss ball I have owned. The gym has them already pumped up and ready, so I have used them before. My question is simple really: how do I know when the ball is at 100% capacity? I don’t want to have it under or over because that probably wouldn’t be of any benefit to me and may not be safe.

So any help is greatly appreciated.

Have Paul Chek do squats on it. If he falls off and breaks his ass (again), there’s too much air in it.
(seriously, try to match what you felt in the gym- but be careful)

I thought that was Juan that fell…at the NSCA conference.

Well I knew it was Juan or the other…

You guys are funnier than an Olympic gymnastics judge at a mathematics convention!

And if there’s not enough air in it there’ll be plenty of hot air around to fill it up.