But I LOVE my comfy chair!!!

The modern-day desk sentence:
"Our bodies have evolved over millions of years to do one thing: move," says James Levine, M.D., Ph.D., of the Mayo Clinic in Rochester, Minn., and author of "Move a Little, Lose a Lot." "As human beings, we evolved to stand upright. For thousands of generations, our environment demanded nearly constant physical activity."

But thanks to technological advances, the Internet, and an increasingly longer work week, that environment has disappeared. "Electronic living has all but sapped every flicker of activity from our daily lives," Levine says. You can shop, pay bills, make a living, and with Twitter and Facebook, even catch up with friends without so much as standing up. And the consequences of all that easy living are profound.

When you sit for an extended period of time, your body starts to shut down at the metabolic level, says Marc Hamilton, Ph.D., associate professor of biomedical sciences at the University of Missouri. When muscles " especially the big ones meant for movement, like those in your legs " are immobile, your circulation slows and you burn fewer calories. Key flab-burning enzymes responsible for breaking down triglycerides (a type of fat) simply start switching off. Sit for a full day and those fat burners plummet by 50 percent, Levine says. more.