WENDY: Has anyone ever used one of those exercise balls? We have one floating around our basement, and so after reading a tip in some magazine I used it as a chair last night while working on the computer. It was supposed to strengthen your core muscles -- balancing on that thing makes you subtly tighten your abs (or else you fall off). It was fun -- and boy, this morning, my abs hurt.

Does anyone else have a fitness toy that they like to use to shake it up a little?

THERESA: I've used those big exercise balls for squats, but I never thought of using it as a chair to work my abs. Amazing. I like resistance bands, especially for strengthening my legs.

YVONNE: The exercise ball is fantastic. Good job using it with the computer last night. That's actually a use I haven't tried. You're right about it being super for toning and slimming the core area. My trainer and I use it for squats, flies, pullovers, crunches and more.

APRIL: I am so glad we are discussing this, because I have no idea how to use those exercise balls. Every time I try, I slip off! Can someone teach me what I'm doing wrong?

DIANE: The exercise balls are a tremendous tool for such a variety of workouts. Here at Fitness Together we have a range of sizes that we use for all of our clientele. You will see someone doing abdominal work in one studio, another person balancing on the ball for ski training and yet another doing hamstring curls by pulling the ball into the core. I could go on and on! I have a ball chair in my office that I utilize each day while at my desk. When no one is around, I stand on it to increase my core strength and balance! WENDY: Wow, after last night I can't imagine STANDING on one of these things!

April, when I've used one it's been for squats. I put it behind my back -- sort of in my mid-back -- against the wall and then do a deep squat. You are leaning against the ball, so you can really lean back and do a good squat. Last night though, I just sat on it and used my laptop. It was great (and sort of fun, too). I've never used it for the variety of exercises that Yvonne has, though...