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FiveThirtyEight

Life

Many of my (male) colleagues have sit-stand desks. With the flip of a switch, the desktop elevates and they can work standing up; another flip and the desk moves back down to its usual position. I had always assumed that my colleagues were using these desks as an excuse to add yet another piece of electronic equipment to their offices. But the other day, hunched over my computer, I caught a glimpse of my reflection in the window and wondered if spending 10 hours a day like that was perhaps a mistake.

It’s worth starting by noting that it wasn’t so long ago that sitting at work was considered a benefit, not a downside. The requirement that one stand all day at work is not typically seen as an enticement, and prolonged standing is associated with varicose veins and lower back pain.

However, a recent flurry of studies suggests that too much sitting is associated with every health issue imaginable: cancer, diabetes, cardiovascular disease and just straight-up death. And since a lot of sitting does happen at work, office jobs in particular, people have started to consider whether some standing might be healthful.

There are various low-tech ways to incorporate standing into one’s day — trying to stand up for any part of the job that doesn’t require the computer, for example. But the sit-stand desk (or its less wishy-washy cousin the “standing only” desk) has ballooned in popularity as a way to work while not sitting.

The combination of sitting and standing provided by such a desk seems to decrease worker-reported discomfort rather than increase it. Workers who use these desks report small reductions in back, neck and arm pain. And these improvements do not seem to come at the cost of lower worker productivity. Although people do stand more when using these desks, they don’t typically stand all day. The decrease in sitting time is on the order of 90 minutes to two hours.

On its own, I think this tells us that if you want to have a sit-stand desk, go for it. (Standing-only desks are also an option, although the evidence that standing all day can make discomfort worse means a sitting option is probably a good idea.) There is maybe some upside, and limited downside. A more complicated question is whether it’s worth it for health reasons — even if you don’t want to spend your day switching your foot position and massaging your impending varicose veins. Studies say the reason to force yourself into standing at work is the potential for the huge health benefits of not sitting.

In one example of those benefits, this paper analyzed a large data set of Norwegians and showed a 65 percent increase in mortality rate for individuals who sat for 10 or more hours a day compared with those who sat less than four hours a day. The men were especially more likely — more than twice as likely — to die from cardiovascular causes. A large Australian study found a 40 percent increase in the risk of death from sitting more than 11 hours a day versus less than four. Several review articles (for example, this one) show similar results from other studies.

It would perhaps not be surprising to find that sitting rather than, say, exercising, is worse for health. But what’s striking about many of the studies on sitting is their finding that sitting matters even when you control for exercise. Basically, if you sit for 10 hours at work, you may be increasing your risk of death even if you exercise religiously before you head to the office. Exactly why this might be isn’t clear, but one theory is that sitting for too long triggers metabolic changes — in the way your body processes insulin, for example — that affect your health.

These studies, however, are subject to questions about whether the effect is really causal. Sitting time is not randomized; that is, the researchers didn’t randomly assign some people to sit for long periods of time and others to do whatever they liked. When you’re looking at non-randomized data, it’s much more challenging to pin increased mortality on sitting. Maybe sitters are different in other ways. Maybe they’re more likely to eat buttery and salty popcorn, for example.

In the Norwegian study on sitting and death, those who sat for more than 10 hours a day were more likely than the less-than-four-hour-sitters to report being in poor or not great health (25 percent versus 20 percent) and were more likely to be obese (24 percent versus 19 percent). Both of these factors may make sitting look worse than it is.

But there are also differences in the people who sit for long periods of time that push in the other direction. Longer sitters are more educated, for example. This could lead these studies to understate the dangers of sitting, since education is typically associated with lower mortality rates.

The fact that the bias goes in both directions doesn’t necessarily make this effect true — that 10-hour-plus sitters have a 65 percent higher mortality rate than the four-hour-or-less sitters — but it does make it harder to shoot down. To draw sounder conclusions, though, we would need randomized data. And, weirdly, standing desks may be the way to get it. Because they make people stand more often, randomizing access to these desks could be a way to manipulate standing time. Examining people who use them and people who don’t could help us learn about the efficacy of such desks in particular, and also about the downsides of sitting in general.

Studies like this are still few and far between, although more are underway. One problem is that if you actually want to detect a change in mortality you’ll need a study conducted over many years. A more viable approach may be to look at intermediate outcomes. This paper, for example, shows that post-lunch glucose increases are lessened when workers have access to standing desks. Glucose spikes are thought to be bad from a cardiovascular health standpoint, so showing that standing matters for something like this is a step towards showing that these desks save your life.

There is no definitive answer in the literature, but reading it all together I find myself more convinced of the sit-stand desk’s benefits than I expected — sufficiently so that the next time I move offices, I’m getting one.

One final note: Some people are drawn to these desks as a way to burn calories. I am sorry to report that the evidence on this is at best mixed, and at least one review article shows there does not seem to be any evidence of extra energy spent by the users of standing desks.

If you want to actually burn calories at work, it’s not enough to stand, you need to walk. Next stop: the treadmill desk.

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