IF YOU SIT more than 23 hours per week (as a passenger, watching TV, at your desk), you have a statistically greater chance of heart disease than someone who stands. Even if you exercise.
I read these data in 2010,  shortly before Gina Trapani talked about her standing desk.  Even though they were derived by studying men and rats (same species in some parts of the internet), they are statistically sound. Since mid-2011, the desk in the photo has gone vertical, enabling me to stand while I work on creative multimedia stuff. My colleagues don't seem to mind.
From the NY Times two years ago:
"Men who spent more than 23 hours a week watching TV and sitting in their cars (as passengers or as drivers) had a 64 percent greater chance of dying from heart disease than those who sat for 11 hours a week or less. What was unexpected was that many of the men who sat long hours and developed heart problems also exercised. Quite a few of them said they did so regularly and led active lifestyles. The men worked out, then sat in cars and in front of televisions for hours, and their risk of heart disease soared, despite the exercise. Their workouts did not counteract the ill effects of sitting." 
I am trapped in a low-MET (low metabolic spend) lifestyle so my standing desks (two at home too) help me avoid a statistical heart failure. As Gretchen Reynolds explains, "Scientists categorise activities by the number of METs they demand. A MET, or metabolic equivalent of task, is a measure of energy, with one MET being the amount of energy you burn lying down for one minute. Sedentary behaviors demand one to one and a half METs, or very little exertion."
So I'm typing this little blog post while standing, knowing I've reduced my risk of blogging myself into a heart attack. It's a lot less stressful than sitting and tweeting.
1. National Institutes of Health -- "Sedentary behaviors increase risk of cardiovascular disease mortality in men", on PubMed.gov, May 2010.
3. Gretchen Reynolds -- "The Men Who Stare at Screens" in The New York Times, July 14, 2011.
Bernie Goldbach is collecting links about health.