AUSTIN -- As comfortable as it seems, sitting down too long can be bad for your health, according to a new health study released this week.

Most of us are putting our own health at risk without even knowing it.

"We’re meant to be mobile, we’re meant to be moving around. In old days you may have been hunting or gathering, and that involved moving," says Dr. Martha Pyron of Medicine in Motion.

Those days are long gone.

"If you’re sitting for eight hours at a time a couple of bad things happen. One is your metabolism drops, you’re more sedentary. Second, you start getting overuse problems cause you’re doing weird things with your posture," she says.

Overuse problems can be neck and back pain, which then makes it harder to exercise later. 

"That then makes you more likely to have heart disease, diabetes, high blood pressure, high cholesterol, all of which are associated with dying earlier," said Dr. Pyron.

For those whose daily grind means sitting behind a computer screen, there are ways to cheat: stand up desks and yoga balls can be healthier alternatives to the desk chair, but you have to know how to use them properly.

"If you lean forward and have bad posture the ball moves too and then you have to use different muscles to stabilize. If you can sit right in the middle and sit up straight then you’re using posture muscles to stabilize which is good for you in the long run," said Dr. Pyron.

If you can, take a walking break every half hour.

"Moving keeps your muscles working, your keeps your joints happy, it keeps your brain better. You’re less likely to have depression and less likely to have those diseases that can kill you," said Dr. Pyron.

Interrupting long periods of sedentary behavior can lower the risk of early death, per Annals of Internal Medicine (http://annals.org/aim/article/2653704/patterns-sedentary-behavior-mortality-u-s-middle-aged-older-adults)

"If you can move, take breaks, set an alarm on your computer. 'I’m just going to walk around the office three times, and come right back down.' There are plenty of studies which show you’re more efficient mentally if you take a little break, go do something active, come right back, you don’t necessarily have to get all sweaty. Just get up and move," said Dr. Pyron.

The study looked at nearly 8,000 Americans aged 45 years and older.