http://blogs.wsj.com/juggle/2011/04/21/the-danger-of-sitting-still/By Rachel Emma Silverman
In recent years, a growing body of research (and a number of prominent news reports, including this, this and this) has suggested that one of the worst things we can do for our health on a daily basis is what I imagine most of us are doing right now: sitting still for long periods of time.
Many of us think that a heart-pumping workout at the gym can counteract eight or so hours of sitting in front of a computer screen, plus several hours of TV time at night after work. (Physiologists call that being an “active couch potato.”) But scientists now believe (for reasons that are still not fully understood) that excessive sitting may be so taxing on our physical health that even a vigorous workout once a day can’t really counteract the deleterious effects. Indeed, it’s as futile as trying to counter a daily Big Mac diet and a pack-a-day smoking habit with a daily jog, scientists say.
When you are sedentary, muscle activity essentially stops, leading to a drastically lowered metabolism and a series of harmful consequences, like an increased risk of obesity, Type 2 diabetes and even death. As one prominent doctor told the New York Times, “excessive sitting is a lethal activity.”
I absolutely believe this. Our bodies evolved constantly moving. We weren't meant to be still for 8 hrs a day at work and then sitting at home in front of a TV.