Too much time on your rear could put your bottom at risk and your life on the line: A new study finds that people who work sedentary jobs have a dramatically higher risk of colorectal cancers.

Researchers compared work history, lifestyle factors and levels of physical activity of 918 colon cancer patients to
1,021 people who didn't have the disease, and ranked their jobs based on the levels of physical activity throughout  the day.

They found that those who spent a decade or more doing work that required little to no movement had more than twice the risk of colon cancer than those who never held a sedentary job.

Non-movers were also 44 percent more likely to get rectal cancer, according to the study in the American Journal of Epidemiology.

That's bad enough… but the news gets even worse for office workers who think time on a treadmill will keep them a step ahead of disease: Daily exercise did nothing to reverse that risk.

The one "caveat" on the study, if you can call it that, is that sitting was linked only to cancers of the rectum and distal colon – not the proximal colon.

But really, how much does that distinction matter to someone who's just been told they have cancer… and the office job they've held for the past decade or so could be the reason?

And even if you escape those cancers, a low-movement job could still put you at risk for just about everything else.

One study earlier this year found that sedentary jobs can be as unhealthy as smoking, causing a dramatic rise in the odds of heart disease, obesity, diabetes and an early death.

Another study, published last year but getting some recent attention thanks to prominent play on CNN, found that women who sat for more than six hours a day were 37 percent more likely to die during the 14-year study period than women who sat for less than three hours a day.

For men, that boost in risk was 20 percent, according to the study in the American Journal of Epidemiology.

Again, regular exercise didn't help – a flurry of activity for 20 or 30 minutes in the evening won't make up for being parked on your butt all day and lying on your back all night.

If you can't change jobs, change habits: If your career keeps you in a seat, find creative ways to get up and get moving as much as you can.

Your butt is on the line here… and so's your life.