Question

The gym has several devices to improve balance. One is the 1/2 ball, flat on one side and raised dome of the other. It can be used for a variety of exercises. What is it called?

Answer

The "1/2 ball" you're referring to is call a Bosu Balance Ball or Balance Trainer and comes in the following (2) variations:

Classic Bosu Balance Ball

The Classic Bosu Balance Trainer is the piece of equipment that, as far as I'm concerned,  started the entire balance training and core workout revolution. It's a versatile piece of equipment that, with a little imagination, can be put to use in more ways than I can count.

The Classic is the Bosu that I own and my wife uses (see photo at right) in the studio with clients. It's worth the extra money over the sport model unless you need to travel with it, but I don't know why you'd want to do that?

Bosu Balance Ball Sport

The Bosu Sport Balance Ball is the little sister of the Bosu Classic measuring in at 45 cm. It's a good option if you've got a tiny home gym, need to travel with it (personal trainer) or want to store it between workouts. The disadvantage of the Bosu Sport is that it doesn't have the nice molded bottom with the handles so it's less adaptable to different kinds of training.

Bosu also makes some peripheral products that can be used in conjunction with their balance trainers, which are the Bosu 3D System,  the Bosu Ballast Trainer and the Bosu Fitness Ball.

Bosu 3D System (Add-on to the Bosu Classic)

The Bosu 3d System is an add-on component accessory to the Bosu Classic Balance Ball It aims to make the Bosu Ball into a complete home gym by adding a balance handlebar and a ciip-on exercise band attachment. The 3D System comes with 3 workouts led by Rob Glick and adjustable resistance tubing but it's rather expensive at $149.

Bosu Ballast Ball

The Bosu Ballast Ball is an interesting concept, until you realize it's just a weighted exercise ball like other companies like reebok have been making for years - it's just got a catchy name. On the other hand, if you need an exercise ball that's stabile (you have terrible balance) the Bosu Ballast Ball is as good as they come.

Bosu Fitness Ball

Another good concept that's late to the party but still worth the $14.99 investment. You can use the handheld Bosu Fitness Ball to take your balance training up a notch by using it in conjunction with your core and balance training (think mini medicine ball).

If you're interested in a Bosu Ball, get the Classic Bosu Balance Ball and save your money on the little add-ons and accessories until you really need them.

Not sure if a Bosu Ball is right for your home gym? Read my complete Bosu Balance Ball Review here and decide for yourself…