Wednesday, May 5, 2010

Herman Miller: The Silent Killer

A lot of science has emerged lately demonstrating that sitting is really bad for you (read this, this, and the bottom two paragraphs of this). Like, really bad! A mere hour or two of sitting does ghastly things. Even if you eat modestly and exercise like a banshee, your desk job, TV watching, and web surfing are making you fat and unhealthy. Consider these facts (I'm quoting from the second link, above):
Every hour spent watching TV (an activity that usually involves sitting) was associated with an 18% increase in heart disease deaths and an 11% increase in deaths overall among 8,800 Australians who were followed for six years, according to a recent report published online in Circulation. People who watched TV at least four hours a day were 80% more likely to die of heart disease than those who watched less than two hours a day. (Americans watch an average of five hours of TV a day.)

A Canadian study of 17,000 adults also found a consistent link between chair time and deaths from heart disease: The more people sat, for any reason, the more likely they were to die of heart disease within 12 years — even if they were slim and exercised regularly.
"Even if they were slim and exercised regularly"! Spooky, no?

This all jibes with three pieces of physiological common sense:

1. Fidgety people have higher resting metabolisms...and don't gain weight as easily. That's been proven, scientifically (sorry, I don't have time to find the link right now, but it's out there). And standing requires the action of tons of small postural muscles. In general, the aggregate of tiny actions during one's day seem to have more impact than twenty strenuous minutes on, say, a stairmaster.

2. People who stop running (due to injury, etc.) and substitute a regimen of walking are often surprised to find that long walking gets them into shape more effectively than short or medium running...even if fewer calories are burned. Time and intensity are both important, but time seems to have the edge. And, for one thing, time spent walking, like time spent standing, is time spent not sitting. It's amusing to consider that wellness might be more about simply "not sitting" than it is about doing anything more pointedly grueling in lieu of sitting. But as I've previously noted, gyms are full of perpetually fat people hammering away at themselves. The effectiveness of that approach seems limited.

3. I find it incredibly difficult to lose weight. And I grew curious enough to try making it my top priority for a year or two. I eventually learned that even with a perfect diet and daily rigorous exercise, I'm unable to lose more than half a pound per week. I finally lost 35 pounds, but it was unbearably slow, required extreme discipline, and left me far less skeptical upon hearing people complain they simply can't lose weight. Science used to smugly insist that since weight loss is simply a matter of calories in versus calories out, you have only your laziness and hunger to blame, but now science is registering some weird things (nothing weirder, by the way, than this). The main weird thing is....sitting is an absolutely huge factor. This seems to be a key (and who's not in favor of effective weight loss keys that don't require monstrous discipline, exertion, and restraint!).

Human beings did not sit for hours per day until a century or so ago. And that's when we started getting fat and sick. It's not what we're evolved for. (And yes, these studies do take into account the fact that people naturally drawn to sitting are constitutionally different than those naturally drawn to standing, walking, and exercising.)

The rich have been comfort-addicted for time immemorial. Money may be a surprisingly inadequate solution to most problems, but it sure does buy comfort! And the rich developed world has been increasingly obsessed with reducing exertion to the very bare minimum, even after an eight hour workday of sedentary labor. Well, we seem to have hit the wall with that.

Solutions: work and surf at a standing desk (the word out there is that after a couple weeks of adjustment, you start really liking it a lot, and endurance increases quickly). Or, if that's too much, use an active sitting chair or a stand/sit chair. Or, to take it to the next level, I actually hear good things about this ridiculous-seeming treadmill desk.

One very simple workaround - unproven scientifically, though it does make sense - is to set a timer whenever you're sitting, and get up for five minutes per hour to walk around a bit, stretch, and maybe go up and down some steps.

Update: I need to stress that it's not just about the higher muscular exertion involved in standing versus sitting that's at work here. The first article linked in the top paragraph includes this fascinating discovery:
"If you're standing around and puttering, you recruit specialized muscles designed for postural support that never tire," he says. "They're unique in that the nervous system recruits them for low-intensity activity and they're very rich in enzymes." One enzyme, lipoprotein lipase, grabs fat and cholesterol from the blood, burning the fat into energy while shifting the cholesterol from LDL (the bad kind) to HDL (the healthy kind). When you sit, the muscles are relaxed, and enzyme activity drops by 90% to 95%, leaving fat to camp out in the bloodstream. Within a couple hours of sitting, healthy cholesterol plummets by 20%."


Chuck said...

To be fair, the calories in vs calories out thing is true, it's just not as simple as one might think to elevate the calories out number.

Kind of like saying, "to lose weight, get rid of some atoms." Accurate but not complete enough a picture to be helpful.

I found this post helpful, thanks.

Jim Leff said...

Yeah, that was the result of bad editing. I fixed the sentence so it makes more sense now.

Jim Leff said...

Argh, I mistakenly deleted a comment (there's been tons of spam lately), so I'm republishing it now.

posted by vhliv:

I don't doubt what you have reported here, but I would like to report my somewhat contrary experience. For the first time in my life I have a purely sedentary job as I am chained to a phone for 10 hours a day four days a week, actually 9 and 1/4 if one subtracts break time. Naturally I expected to gain weight, and one fellow who has been there for several years says he has gained 40 lbs in 5 years. I've also noticed that several of my colleagues have gotten slightly plumper in just the few months I have had this job. I, however, have lost weight.

How did this happen? Two things. First, I now walk 25 minutes every morning, although to be honest, I don't see that as a particularly big change as I used to walk about 1/2 hour every day as part of my commute, although I now often also walk another 25 minutes in the evening. Second, and I think more important, I stumbled into a rigorous regime of portion control early on when I used one of the small plastic chinese takeout containers -- the white ones with a clear plastic top -- for my main meal every day, which I supplimented by some crudities, usually carrots, and fruit for my main meal. I found I was full, but far from stuffed, and decided to make using that container a habit. Then I have a sandwich and apple for supper, with the same result. Even though I have a snack when I come home, I'm rarely stuffing myself.

I hasten to add, I am not someone who loses weight easily, and I certainly do not attribute my weight loss to those ten hours sitting on the phone explaining people's bills to them. Still a few prophylactic measures like including a significant walk to one's commute and portion control as well as adherence to a few quirky principles -- I make it a habit to take the stairs and avoid the temptation of the elevator at work -- can in my experience prevent a sedentary job from leading to a health disaster.

Anonymous said...

That does it. I'm going back to slow-riding on the stationary bike while I'm watching tv. If only I could figure out a way to attach the laptop to the handlebars...

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