If you have been reading my columns for any length of time, you know by now that my favorite piece of exercise equipment is the large stability ball.

I teach four classes a week completely devoted to using the ball. Even though these classes are structured for all ages and levels of fitness, they are not "wimpy" workouts. And I can safely say that they offer the most effective workout for the center core, or "powerhouse" of our bodies, along with increasing our sense of balance. All of this contributes to good posture and muscle strength.

So, you can imagine my delight when I found a "ball chair" advertised in an exercise equipment catalog. I wrote the following question to our Ergonomic Strategist Dave Pfeil:

Dave, I just received the 2002 Catalog from Power Systems, and they have a ball chair. It is the huge stability ball on a rolling base (adjustable in height) and includes a backrest. I am so tempted to get it for myself … what do you think?" -CK, You can find his answer here.

Even though I didn't agree completely with his answer, I did buy myself a ball chair for Christmas. It arrived in late January and I have been using it ever since. In this article I am going to share the ins and outs of using a ball chair.

A ball chair isn't for everyone

As you know, I am a ball devotee. I am also someone who spends a large part of my working and playing time in front of the computer (so having the right kind of chair is imperative). And, once I have paid for something I am dedicated to making "it work."

I will admit that it has taken some time to get used to sitting on the ball, but I can finally say that I can't imagine going back to my former computer chair. And, as a bonus, I do feel that it has been a huge postural help along with offering an ergonomic solution to many tiring hours at the keyboard and on the mouse.

If you love working out on the ball and have the gumption to go through some of the adjustments and experiments I will describe below, go for it - but with the advantages of having advice from someone who has been-there-done-that.

Getting it set up

Along with my order for the chair, I also ordered a classy foot pump. The day the two arrived, I got busy trying to pump up the ball (and, Dave, the rubber for the chair is so thick, it would take an incredibly sharp object with a great deal of force behind it to ever puncture it). I pumped and I pumped and after getting so little air into the ball, I drove to a gas station to use their air. That turned out to be a total waste of time.

Fortunately, one of the clubs where I teach has an electric air pump for all of their balls. Eureka! I had the ball pumped up to its maximum size - I even took a yard stick with me to check the size. As soon as I had it positioned on its metal base (which is on wheels and does have plenty of mobility, so there is no problem with swiveling) I perched on top of it and went to work on the computer. After several hours, my buns were burning and aching. It was like sitting on a rock for hours.

And this is the secret of a ball chair. You must play with the level of air until you have a comfortable, yet supportive cushion. You must also work with the heights of the wheeled base and the small backrest until they are correct for you and your work area. All are adjustable, but, I must admit that I was glad to have my foot pump when I let out too much air.

And, of course, you must follow Dave's suggestions for positions of your eyes and monitor, your arms and keyboard, etc. The good news is that the rubber is so solid that once you have the ball at the perfect level, it stays there. I haven't pumped for ages.

The advantages of being "on the ball"

Once it is set up properly, the ball is a terrific tool. There is no way that I can slump, which I could in the traditional chair (thus, my eye level is always right on). There is no way that my arms can lose their positions (since there are no arm rests), and I have to maintain my center to stay in balance.

It doesn't happen that I fall off the ball, but in the beginning I would forget that I was jumping up from a ball when the phone rang. It is my theory that when we are in balance and centered, our thinking and work is also in balance and centered.

And, Dave was right when he said it would be "fun." That is one of the best parts, along with being able to take a quick break. I just lift the ball off its frame and do a series of abdominal crunches and gluteus leg lifts.

So, if you love adventure and the advantages of working with a stability ball, get yourself a ball chair.