A desk job is supposed to easy on the body, but sometimes it's downright painful. And it's not just your demanding boss or annoying coworker who's a pain in the-you-know-what. That physical pain comes from an eight-hour day sitting in one position. In fact, sitting puts more pressure on your back than standing does. Exercise balls, or stability balls, are supposed to be the posture-perfecting, muscle-working, pain-relieving alternative to the office chair. But studies on exercise balls show they don't live up to much of the hype.
Posture Truth
If you covet a model's perfect posture, sitting on an exercise ball at the office isn't going to send you down the runway anytime soon. A 2009 study published in “Scoliosis” found little difference between sitting on exercise ball versus an office chair. On both exercise ball and office chair, participants began slumping over after about 30 minutes. Worse, another study found participants experienced more spinal shrinkage from sitting on an exercise ball than an office chair, according to an article in the March 2009 issue of “Applied Ergonomics.”
Muscle Work
With no back and armrests to support you, balancing on an exercise ball makes your muscles work harder than when you're kicked back in an office chair. To keep from rolling off you have to focus on engaging your core muscles, increasing movement in the trunk and lumbar areas. However, this increased muscle movement is the same as if you were simply sitting on a stool. And constantly making tiny adjustments to stay balanced throughout the workday may leave you fatigued.
Active Sitting
“Active sitting” may sound like an oxymoron, but it's exactly how to work your muscles on the exercise ball. The key, however, is moderation. An exercise ball is best as a break from the office chair, not as an all-day alternative. Just 30 minutes of “active sitting” on an exercise ball works your core muscles without wearing you down. Sit on the ball with your feet flat on the floor, straightening your back and stretching it as tall as possible. Puff out your chest and pull in your chin. Then push your shoulders down and pull your shoulder blades toward each other. If you're having trouble aligning your body in a vertical line, try lightly bouncing up and down on the ball. When you tire, give yourself a break.
Ball Sizes
Just as an ergonomic setup of an office chair is important, so is the setup of your exercise ball. The diameter of the ball must match your height. If you're a shortie standing 5 feet or under, try a 45-centimeter ball. For heights of 5 feet 1 inches to 5 feet 8 inches, use a 55-centimeter ball. For heights of 5 feet 9 inches to 6 feet 2 inches, use a 75-centimeter ball. If you tower above that, try a 75-centimeter ball. If your weight-to-height ratio is on the higher side, that extra weight will compress the ball down more, so you may need a ball in a larger diameter.
