Don't worry, the lamps, vases and windows are safe. Exercise balls (a.k.a gym balls, flex balls, physio-balls, or Swiss balls) are for adults who want to improve flexibility, strength, balance, and coordination. With no motors, gears, or electricity, these large, brightly-colored, air-filled rubber balls may be the cheapest piece of home exercise equipment out there. So, should you buy one?

Not a Medicine Ball

For the benefit of those who are old enough to remember medicine balls from grade school gym class, exercise balls are nothing like them. Though medicine balls are also used for strength and flexibility training, they are generally made of leather or vinyl, are smaller, and weigh anywhere from 6-10 lbs. Exercise balls weigh only 1 lb and are meant to be sat or laid on, rather than passed around. They also need to be pumped up with air—a task that is best done at the gas station with an electronic air pump to get enough pounds of pressure inside the ball.

What Do You Do With an Exercise Ball?

Manufacturers of the various models of gym balls suggest they will help you achieve all of the following goals:

  • Weight loss
  • Toning
  • Shaping
  • Flexibility
  • Strength
  • Aerobic fitness
  • Balance
  • Coordination

Let's see what the fitness specialists have to say. Ken Baldwin, spokesperson for the American Council on Exercise and 1999 IDEA/Life Fitness Personal Trainer of the Year, recommends exercise balls for resistance and flexibility training. Specifically, he uses them with clients "to develop core strength in the abdominals and lower back areas." He adds, "It works different muscle groups [than other forms of exercise] and works on balance and coordination."

When asked whether one could get an aerobic workout on a gym ball, Baldwin jokes, "You could do a million wall squats, I suppose." These balls are not a great way to get a cardiovascular workout. Baldwin explains, "It's an addition to your workout." He has clients who spend about eight to ten minutes on the ball during a one hour session.

Exercises you can do on the ball include:

  • Hamstring stretches
  • Quadriceps stretches
  • Back stretches
  • Side stretches
  • Crunches
  • Push-ups
  • Squats

Getting the Hang of It

If it's hard to imagine doing your sit-ups and push ups on top of a rubber ball, you're not alone. Working out with an exercise ball will likely take some getting used to. In fact, Robert Leach, MD, former editor of the American Journal of Sports Medicine , cautions, "When something is new to you, you need to be careful because you may not know your own limits or those of the equipment." He feels that exercise balls require more instruction at the outset.

"It's a new piece of equipment for many people," says Baldwin. He believes that it is difficult for beginners to get enough detail from the instructional videos and encourages people to work with a trainer in the beginning. He also encourages clients to develop good mechanics with regular weight training before working on the ball.

Pricing and Sizing

The cost and size of these balls go hand in hand. The taller you are, the larger the ball you need, and the more it costs. With a price range of $15.00 to $35.00, depending on the brand, taller people don't make out too badly.

Surveying the various manufacturers of exercise balls reveals that there is no standard sizing in the industry. For example, one company's smallest ball may be 45 cm in diameter and designed for people under 5 feet tall, while another's smallest is 53 cm and designed for someone under 5 feet 3 inches tall. To determine the right size for yourself, Baldwin advises lying with your back on the ball and your feet on the floor. Your knee joint should be at a 90° angle and your back parallel to the floor.

As far as the quality of the various brands, Baldwin says, "They are all pretty much the same." He adds, "Some have feet at the bottom to stop it from rolling, but they tend to get in the way."

Safety Tips

To use an exercise ball safely, Baldwin says you really need the correct size for your height. Other than that, he feels that the only people who may have difficulty working out on the ball are those who have trouble with balance, such as some seniors.

Here are some tips from the Gym Ball Store for using the exercise ball safely:

  • Read all the instructions before starting your exercises.
  • Start with the easiest exercises first. Move on to advanced exercises after you have mastered these.
  • Breathe slowly and deeply. Don't hold your breath.
  • Hold stretches for 20-30 seconds, and don't bounce.
  • Pay close attention to specific instructions regarding positioning of your low back and pelvis.
  • Wear gym shoes.
  • Perform 8-10 repetitions of the strength training exercises.