I had a call from a lady the other day who inquired as to where the best place to buy one of those big round bouncy thingys. Being facetious by nature, and just a little ornery, I asked if she meant one of these
or perhaps this 
After a few flustered moments, we settled upon this 
too bad I thought, because my next choice was a doosey! Anyhow, she wanted to purchase a stability ball. AKA an exercise ball, a Swiss Ball, a Therapy Ball, Physioball, etc, etc, etc. I advised her on what type of ball to get, what size, and where to purchase it, and she was happy, just as I am happy to segue into my article on The Stability Ball!
In my opinion, the stability ball is the first piece of equipment anyone should buy when they are looking for exercise equipment. There are a myriad of books and videos about training with stability balls. It is the most versatile tool in the personal trainers arsenal. You can sit on it, stand on it, lay on it, jump on it, jump off it, land on it, and not ot be overlooked, you can hold it while your erstwhile trainer attempts to knock it out of your grip, Aka (Acyclic Impact Training), one of my clients favorites! There are literally hundreds, if not thousands of exercises that one can do with this ball.
When I interview new clients, and if they have one of these, I have them sit on it while we discuss their goals, needs, etc. Within seconds I can determine their core strength, proprioception, balance, stability, etc. Sometimes I will have them do a few simple movements for me to aid in this process, but usually siting on it is sufficient. Therein lies one of the most basic benefits of the ball, taking the place of your chair/couch. By sitting on the ball in correct posture, and any other way of sitting on the ball gets uncomfortable after a few minutes, you begin to develop core strength, and balance, simply by supporting yourself in a gravitational pull.
Almost anything a workout bench can do, the ball can do better! Step ups are an issue, but bench presses, seated shoulder presses, front leaning rows, 
etc are dramatically more effective because of the ball and it's inherent demand for stabilization while you use it. Doing a dumbbell bench press on a bench can be demanding for the chest/shoulders/triceps, but does next to nothing for the core/legs/balance/ etc. Try doing a 1 arm seated shoulder press on the stability ball and tell me it feels the same as the bench. Not hardly! Substitute the ball for a bench for any of the exercises you normally do, and I guarantee you will notice an increase in balance, and stability almost immediately. We do lunges with the non weight bearing leg on the ball, roll outs for the core, all crunch variations, leg curls, hip raises, back and forth ball passes, Ys,Ts and Is, and a whole host of other movements 
that keep the workouts fun, demanding, and increasingly beneficial! We use it to warm up, to stretch, to cool down, and everything else you can imagine.
When selecting a stability ball, you definitely get what you pay for. Cheaper is not better! Get one with a rated burst resistance of at least 1000 pounds, or else you will find yourself flat on your back on the ground, looking up at a pair of rapidly descending dumbbells wondering how you ever got in this mess in the first place. Also, one with a textured surface helps prevent slipping. They usually come in 55 65, and 75 centimeter models. If you sit on one that is properly inflated, your hips should be slightly higher than your knees. Bounce up and down on a prospective model and see if it gives you a supportive and solid feedback. If not, keep looking. A couple of brands I recommend are Fitter and Versaball. If all else fails, give me a call, and we will get you fixed up with an industrial model like this
One word of caution, make sure you allow at least 45 minutes to an hour to digest your JEN Bar before you play on one of the above mentioned toys, or else you may end up like this
