You probably know that being a couch/desk potato is bad for health. Stiff joints, achy muscles, numb limbs are just some of the familiar side effects of too much time spent parked in a chair, and being sedentary is also linked to weight gain. Even worse, it can shorten your life, too. That's the conclusion of a recent study conducted by the American Cancer Society.

And it doesn't matter how often you hit the gym: After studying 123,000 people, researchers found that women who sat for more than six hours per day were 37 percent more likely to die prematurely than those who sat fewer than three hours a day -- even if they got regular exercise. Men were 18 percent more likely to die early.

When participants reported sitting for long hours without engaging in a regular exercise routine, the results were even scarier: Women who sat for six hours a day and didn't work out were 94 percent more likely to die early compared with those who sat fewer hours and were very physically active. Men were 48 percent more likely to die.

But what explains the link? "Prolonged time spent sitting, independent of physical activity, has been shown to have important metabolic consequences," says lead researcher Alpa Patel, and this can negatively affect cholesterol, blood pressure, glucose levels and other factors associated with obesity and cardiovascular disease.

So what do you do if you have a desk job or are otherwise stuck sitting in a chair for prolonged hours everyday? "For optimal health and longevity, adults should engage in at least 150 minutes of moderate to vigorous activity per week," says Patel. That averages out to a minimum of 20 minutes a day. In addition, Patel advises cutting time spent sitting -- according to the study, people who sat for less than three hours a day had the lowest risk. Try these tips to get your daily dose of movement:

Tips to move more and sit less

Take more breaks from extended sitting. Set an alarm on your computer to remind you to get up from your seat once every hour. Stand up or walk around for a few minutes -- studies have shown that frequent short breaks are beneficial for your waistline and heart.

Take a 20-minute stroll everyday -- it gets your blood flowing and counts toward your daily out-of-chair quota.

Skip the phone and email at work. Instead get up and walk over to a coworker when you want to discuss something.

Walk or cycle instead of drive whenever possible.

Choose relaxing activities that keep you moving. Instead of sitting down infront of the TV, go for a walk in the park, window-shop, a visit to the museum, or a game of bowling.