This $595 chair turns sitting into exercise—there's just one problem

According to experts, sitting too much can kill you.

"Sitting is more dangerous than smoking, kills more people than HIV and is more treacherous than parachuting. We are sitting ourselves to death," writes Dr. James Levine in his book "Get Up!"

Standing desks are one effective solution, says Levine, but high desks that keep you on your feet aren't available in all offices. If that's the case for you, there are other ways to stay active from 9-to-5: You can pedal under your desk with a mini exercise bike or choose from a variety of active office chairs designed to give you a subtle workout.

One such chair that turns sitting into exercise, the SitTight, is seeing success on Kickstarter: It exceeded its goal by more than 300 percent and raised nearly $120,000 from 299 backers.

The SitTight puts your core to work by making you balance on an air bladder on the base of the chair.

There are three different levels of "active sitting" you can work through, with the end goal of balancing right on the center of the ball with your feet on the platform of the chair. You can also inflate or deflate the air bladder as needed.

You can increase or decrease the air pressure to make it more or less difficult
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You can increase or decrease the air pressure to make it more or less difficult

After a week of trying out the SitTight, which can be pre-ordered for $495 now, but will normally cost $595, I had one problem: I couldn't sustain it. Even though I'm a marathon runner and a tennis player, I found I had to switch back to my normal office chair at least once a day.

When I first sat down, the chair felt great. There's a comfortable mesh seat, the chair swivels and the height is adjustable.

And sitting without a backrest definitely made me much more aware of my posture, which often needed to be corrected.

Throughout the day, I felt like my core was engaged, particularly when testing out level three, but unfortunately I felt it more in my lower back, and not in a good way. My back killed me.

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A co-worker had a similar experience after trying out the SitTight: As he puts it, the chair "added a level of muscular stress to my lower back that I was unfamiliar with coming from a history of sitting in backed chairs."

That said, I only used it for a week. Since I like the concept of active sitting, I've decided I will continue trying out the chair for the next month using different levels of air pressure. At that point, I'll decide whether or not to ditch my normal office chair for good.

But $600 is a steep price to pay for a chair without a back or armrests, especially if it leaves you aching.

Besides, as a UT Southwestern Medical Center study indicates, exercise may offset the dangers of sitting: One hour of activity can make up for six-to-seven hours of being sedentary, researchers found.

An hour of jogging outside doesn't cost a dime. Plus, it would mean getting to keep my backrest.

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