For most of human history, work has been a physically demanding activity. Our cavemen ancestors chased down mastodons and hurled spears into their tough, but tasty flesh, American homesteaders tamed the wilderness into productive farms with nothing but grit and sweat, and just 60 years ago, the majority of men in America flexed their muscles on factory floors or construction sites. FAST-FORWARD TO TODAY Instead of feeding ourselves by the sweat of our brows, most of us just slouch in a chair all day in a climate-controlled building while we push buttons and send documents through the ether. And the sitting doesn't end after work. When we get home, we plop down in front of the TV to watch reality shows...
