Q: My job requires me to sit a lot. How is this affecting the health of my heart, and what can I do about it?

A: London, England 1953 - Dr. Jeremy Morris reported that London's double-decker bus conductors, who regularly climbed 500-750 steps daily to collect fares, developed heart disease less often than did the drivers of those buses, who sat all day. In the same report, Morris also proved that letter carriers who walked or cycled their routes acquired heart disease infrequently compared to sedentary post office workers. With this single paper, Occupational Cardiac Epidemiology was born!

London, England 1956 - Morris studied work uniform sizes ordered by city bus garages, to compare the body measurements of conductors to drivers. He showed that drivers "measure more round the chest and waist" than conductors.  And, he found that the comparatively lean conductors had rates of sudden cardiac death half that of the relatively portly drivers. With this paper, metabolic syndrome became a recognized workplace issue, though it was not so named for another 30 years!

Today it seems like doctors have always promoted regular exercise as an essential strategy for staying well. But in fact, pioneers like Morris faced an uphill climb. It took decades before research like theirs won Medicine over to the simple idea that "some exercise is better than none, while more is better than some" (Paffenbarger, 1996).  

Now in our "enlightened age" of nuclear and echo cardiology, intracoronary stenting, and cardiac transplantation, Morris's studies with their "obvious" conclusions and quaint methodology may seem like amusing relics from the dust bins of history.  Even the idea of "epidemiology," as in the "study of epidemics," seems like the work of a bygone era.

Think again. I plopped at my
desk like a portly bus driver to write this. Most likely, you sat like a British postal clerk while reading it. In fact, we probably have "sat the day away." Next, consider the modern "epidemics" that beset us--obesity, metabolic syndrome, diabetes, and heart disease. Have nearly six decades of Occupational Cardiac Epidemiology taught us anything?  Not enough, apparently, to make us live what we've learned.

Now I present another British physician, Dr. James Levine, who conducts research at the Mayo Clinic in Rochester, Minnesota. In 1999, he tackled the question of why some people gain weight and others don't, even when they consume equal calories. In controlled research settings, he pinpointed the difference. Subjects who gained significant weight simply sat more than those who gained little weight, two hours daily on average. He had found The Sitting Disease in Rochester, Minnesota, the same phenomenon that had caused premature heart disease among the London bus drivers studied forty years earlier by Dr. Morris. While we would now call his countryman's research simple and quaint, Dr. Levine's seems best described as NEAT--that is, Non-Exercise Activity Thermogenesis, his term for the burning of calories by simply increasing ordinary daily motion and limiting inactivity.

He and other researchers have since linked prolonged sitting to heart disease, diabetes, and lipid abnormalities. Conclusions include:

--Sitting more than four hours a day watching TV has an 80 percent increased risk of death from heart disease compared to two hours or less.

--The increased risk remains independent of other factors such as smoking or diet.

--The increased risk comes with any type of daily extended sitting (in front of the TV, behind the wheel, at a work desk).

--Periodic vigorous exercise, such as a gym workout, does NOT offset the risk imparted by a day of prolonged sitting.

--One must sit less and move more. Even just standing burns triple the calories as sitting. Leg muscle contractions that happen automatically while standing trigger important processes related to the breakdown of fats and sugars.

--Sitting ends these muscle contractions and slows caloric burning.

Dr. Levine advocates a new technology to counteract The Sitting Disease. He has demonstrated the effectiveness and acceptability of a work desk mounted on a 2 mph-maximum treadmill. Called the "walkstation," it does what it says, providing walking at a work station. 

Having tested a walkstation, I can advocate that it effectively treats The Sitting Disease. And, it allows full work productivity. Sadly, I don't own one (yet). I do use an ordinary treadmill and recumbent station bike at home while doing the extensive reading my job requires. At the office, I do all my telephone-line dictation while using an exercise stepper. Still, I sit more hours than I'd like. That's why, I believe, the uniform of a London double-decker bus driver would fit me better than that of a conductor, unfortunately. 

I have The Sitting Disease. So do you. I know what I must do; so do you. Let's do it. Or else, as yet another Brit told us in 1873,"Those who think they have not time for bodily exercise will sooner or later have to find time for illness." - Dr. Edward Stanley, Liverpool, England 1873. 

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