A study by Kansas State University says that people who spend more than six hours sitting each day are at higher risk of cancer, heart disease and diabetes. Which means you need to be taking more standing breaks (at least once every 30 minutes) -- and perhaps using "healthier" chairs such as the BalanceBall from Gaiam. The research involved 63,048 middle-aged men but US scientists say the findings are likely to also apply to women.
Chairs such as the BalanceBall Chair are designed to provide core strengthening, comfort and ergonomic back support and help to improve spinal alignment and reduce nerve compression. Studies on the benefits are inconclusive (see http://tinyurl.com/3kfkvrp), but if you decide to give one a try, the Gaiam product is reasonably price and well-designed.
The Gaiam chair is designed for heights of 5’-5’11" and weights up to 300 pounds. The BalanceBall Chair comes with a professional-grade, anti-burst exercise ball and includes a desktop workout guide to provide an effective low-impact workout and stretching routine. Even if you don't find benefits to using the BalanceBall as an office chair, it makes a fine exercise accessory.
It comes with an exercise ball (which you can remove from the chair frame for other exercises), a support bar, and an air pump. The chair -- available in a variety of colors and models -- has rolling castor wheels that are lockable to prevent movement when you're using it to work out or stretch.
The BalanceBall's stable, lightweight base is made from molded PVC. The exercise ball itself is made from vinyl with no latex content. Some assembly is required, but it's easy. I had the entire chair assembled and the balance ball inflated in about 15 minutes.
If you do try the BalanceBall Chair, be patient. It takes a bit of getting used to, as you're going to have to use more balance than with a traditional chair. Prices range from $59.98 to $79.98.