Is there a study that doesn't assume correlation == causation? Yes, lots of people who are generally unhealthy also have jobs that require sitting for hours at a time. But what does that mean for someone who lives an otherwise healthy lifestyle?
Let's say person A burns 1000 calories a day at his job, and only sits for a few hours when he goes home. Person B burns 1000 calories in his off time, but sits at work for 8 hours. Is person B still more likely to suffer health defects and die early? If so, why?
All the studies so far indicate sitting (or other forms of inactivity) are bad no matter how much you exercise at other times.
The best natural experiment was the London bus driver study which showed huge differences in heart problems between drivers (sitting all day) and conductors (standing all day). Both were drawn from the same pool of employees and randomly assigned roles, so the experiment was naturally controlled for everything except the difference in behavior.
There were some other differences such as drivers having a more stressful job and conductors having more social interactions which might explain some of the differences in outcomes apart from the sitting/moving difference. But in any case, sitting for hours a day at a stressful job with minimal social interaction is incredibly bad for your health. Programmers take note!
Interesting. It would be a bit more legitimate of if the difference was between standing and sitting bus drivers (assuming there was some way to stand and drive a bus).
Or, straight to the point, if there was a study involving standing programmer and sitting programmers... preferably one in which the roles were randomized, because I'd suspect that programmers who've already chosen to stand while they work are probably a more health-conscious lot as it is.
I can only thing of a few other differences besides sitting/standing people in this study that might make a difference. One is that I imagine the standing person absorbs the constant vibration of the bus better than the sitting person. Long term vibration is known to have deleterious effects.
I don't have access to the original paper but from the summary here http://www.epi.umn.edu/cvdepi/study.asp?id=13 it looks like the study was only observational, roles were not randomly assigned.
It is relatively straightforward to control for things like "exercise from other activities" and underlying comorbidities in an attempt to compare "like with like" even for non-randomized studies.
One should also keep in mind that while correlation =/= causation, showing a strong correlation is a step along the path toward showing causation.
It is interesting is that an early study on the health impact of activity compared bus drivers and bus conductors, who also differ in sitting/standing:
I have to admit, this sounds a lot like that 8 glasses of water a day hocum that was floating around a few years back. Somebody finds some vague correlation in an abstract and blows it way out of proportion, leading to headlines that frankly don't make much sense.
You need about two quarts of water a day, but you can get this by consuming fruits and vegetables that range from 84% (apple) to 96% (iceberg lettuce) water by weight [see link below]. Drinking eight glasses of pure water a day is ridiculous unless you consume no food at all.
I don't think there's anything ridiculous about drinking 2 quarts of water per day. I easily drink 48-144oz of pure water per day with the 48oz bottle I carry with me everywhere I go (http://store.nalgene.com/Silo-p/2178-0048.htm)
Saying it's necessary to drink that much water might be ridiculous, and perhaps that's what you meant, but I don't think there's anything ridiculous about the activity itself.
I just opened a coworking space a couple of months ago. It used to be an auto shop, so we tried to maintain that feel. My favorite part is the old hydraulic lift that we converted into a standing height desk.
I recently built a setup at home[1] using a commercially available powered lift frame[2]. Only been using it for a month or so now, but the ability to stand during the day and sit for things like gaming is great.
One reason I live where I do is so that I am within a mile (which, for me, is walking distance) of much of my shopping and from the county library branch. Being able to walk to do errands reduces driving, which reduces sitting, and increases exercise.
At my computer keyboard, where I live continually, I sit on an exercise ball rather than any kind of chair. Even at that, I should probably get up and move around more, but at least I have the routine of a homeschooling parent of three children still living at home to provide interruptions and occasions to change my posture. It's hard to optimize for everything, but so far I've avoided the worst of the health symptoms mentioned in the article kindly submitted here, even though I am already of middle age.
My understanding is walking rather than than driving for instance is NOT a solution to this specific issue (It's great for other reasons).
It is in part, as in you might sit for 13 hours a day so 30 mins less sitting makes you 3% better off but really it's not the solution. Similarly to getting up and walking around, if you do it 5 mins ever hour that's 4% better off.
My understanding is these studies are saying to make change you need to stop sitting for large periods of time (ie reduce by 50+%), if you don't want to die/become crippled early.
I second this. I try to sit on an exercise ball as much as possible at work (sitting, bouncing, stretching on it). I can't usually make it for a full 8-10 hour day, so I usually switch to a regular chair with back rest in the afternoon. Other than walking around, the variety helps me.
This sounds very like Stanley Green (http://en.wikipedia.org/wiki/Stanley_Green)a very well known english eccentric who used to walk up and down oxford street with a sandwich board that read “Less Lust, By Less Protein: Meat Fish Bird; Egg Cheese; Peas Beans; Nuts. And Sitting,"
I believe one of his thesis was that to much sitting led to horrors like the Rolling stones and the whole permissive 60’s
He was a well known sight to any one who worked in central London pre 1993 when he died.
"Sitting" (or more specifically, the way I "sit" all day) resulted in me having pretty awful back pain that required treatment earlier this year. I had bad posture spent 4-5 hours stationary writing code. Having a standing desk would have probably helped me to take more breaks and move around. A little app called Kitchen Timer, combined with a very mild set of stretching/exercises works for me now. I don't have heart problems. My "inputs" match my "outputs". I've maintained my weight within 5 pounds for 10 years.
The thing that bothers me about this article is the way it's presented. It's designed to scare ... and I know first hand that it works. Growing up, my mom wouldn't let me stand anywhere near the microwave because of something she saw on 20/20. We heated up food the same way we lit fireworks ("strike" and "run!") When I purchased my first cell phone she panicked about the RADIATION and warned me against using it regularly (Chernobyl === Magnetron to her). My mom watched 20/20 all the time!
I have no interest in a standing desk. I work well sitting down, and the timer gives me a nice reminder to stretch out which I can choose to ignore if I'm focused on something I can't pull away from. I smoked as a teenager ... maybe I'm being naive and using anec-data, but my chair is no Marlboro.
Standing desks can hurt you if you don't wear proper shoes and/or use some kind of standing mat; regular desks can hurt you if your chair is unergonomic (there was an article on HN about this two weeks ago.) In a similar vein, you can develop RSI if you use an poorly designed keyboard, but that doesn't mean typing will eventually give you RSI.
Lately I've been using my phone to do a cycle of 15/5 minutes sitting/standing, with standing time also being a break from the computer. It's worked really well. The break time is not really an interruption; 5 minutes is enough for most small chores, and if I don't have any of those, I can use it for mindfulness practice. Plus chopping it up gives me better estimates about time usage and how much I can get out of any given work day - after a certain point it becomes clear that I'm spending most of each cycle on distractions, so I'll start adjusting my plan to match reality.
I could probably use Pomodoro or any similar cycle and also get good results, I just happened to try this first.
Too much of anything is bad for you. Too much sitting? Get up and move around. Too much standing - take a load off. Too much sugar, too much caffeine. How's this any different than the standard saying of "all in moderation".
Well, this article is rubbish and is pretty typical of crappy scientific reporting.
However, I like thinking about ergonomics. Do many people here recline while working? I've been working for a year now, laying back on a couch, feet up and head on a pillow. It works well, but even before this I had carpal tunnel which this doesn't help (it did for a while though). I've resorted to padded gloves that ease my pain:
I've been reclining a lot and now my right arm is painful. I'm not typing with it at all for the next two weeks. I need to work out some system of props to rest my elbows on.
Standing all the time isn't healthy either, but one thing standing desks promote better is taking breaks more often. I'm more willing to walk around and stretch if I'm already standing, than if I'm sitting.
I've been using a GeekDesk for 2 years now. I recently purchased a LifeSpan Treadmill (just the base) for my standing desk as the next step, and really like it. Careful though, you can't go from sitting to treadmill, it's too much body shock, you'll need to ease into standing for a few months first.
Price is steep on these, presumably due to the motors. Is there a similar desk that you can elevate with a simple hydraulic foot pedal? Kind of like the chairs at a hair salon.
I've been thinking about getting a sit/stand desk for a while, but don't like the electric ones as they seem really slow. This seems the nicest of the manually operated ones (better looking than the steelcase one IMO).
Or lying on a couch. All studies compare sitting with walking. How about sitting vs standing? Or sitting vs lying? When I work, I prefer to lie on a couch rather than sit at a desk. And I am not kidding - I am more productive that way.
This LA Times article, like every article that you ever see discussing any of these results, describes a causation: "sitting cuts about 22 minutes from their life span". None of these "studies" were "experiments" that are capable of demonstrating causation: they are either cohort studies or surveys, and are only able to demonstrate correlation.
In this case, "The authors constructed a life table model that incorporates a previously reported mortality risk associated with TV time. Data were from the Australian Bureau of Statistics and the Australian Diabetes, Obesity and Lifestyle Study, a national population-based observational survey that started in 1999–2000. The authors modelled impacts of changes in population average TV viewing time on life expectancy at birth."
We thereby have to ask, what is the more likely explanation: that sitting causes your life span to decrease, or that the same things that cause your life span to decrease make sitting, or watching television, something you do more often? We aren't doing experiments where we assign people into groups, one which will sit for most of their life and one which will stand/walk, so we can't assume the causation.
Maybe you don't have any friends, and maybe that is why you sit inside all day watching the television. Some people believe being a social outcast directly leads to health issues, but one could also point out that friends often are the people who goad you into seeing the doctor for that thing you never cared enough about, or are quite literally the people who pick you up when you fall, maybe calling 911.
Alternatively, it could be that your life really sucks, and you need the outlet of watching television to make your life feel more reasonable. Things that cause peoples' lives to suck might be abusive relationships, chronic illness, or stressful jobs (and other studies, I believe even real experiments, and I even further believe demonstrated mechanisms, show that stress leads to health problems).
Some might argue "it is easy to control for people who are dying and remove them from your study", but it is very difficult to control for subtle effects, and we are talking about a subtle effect here. This is especially true once you look into compliance effects: people who don't sit around all day watching television are probably also the kinds of people who visit the dentist regularly, or simply eat better food.
The result of this mistake is that it could even be dangerous to be making claims that sitting reduces your lifespan: maybe by telling the people who are sitting around watching television that its unhealthy for them (again, based on no direct evidence) causes them to now feel bad about watching television, increasing their stress, or even causes them to push themselves even further to exercise, when they were sitting down because their knee was already giving out.
A lot of people, at this point, get angry at shoddy science reporting. That's a real problem: articles like this blow studies that are correlations into causations. The result is that people hear every couple years opposing information on some debates they care about (such as whether something like wine or aspirin is "good for your heart"), and eventually decide "it isn't like scientists know anything" and "give it a year, we'll learn something new", something they then apply to other branches of science (like evolution).
But, frankly: the scientists who are publishing these papers really need to use less ambiguous wording--especially if they are not going to be really proactive reaching out to press to be involved in the writing of the articles, making certain the right kinds of hedges get quoted by the reporters (which may scuttle the article, as maybe it is no longer interesting to them: in comparison to bad information spreading, less reporting should be a positive thing)--as I think they are complicit in the confusion.
This paper uses wording that technically doesn't imply a correlation if you know what all of the words mean and you are careful with your reading, but to any normal person they are quite clearly saying "X causes Y": "The amount of TV viewed in Australia in 2008 reduced life expectancy at birth by 1.8 years (95% uncertainty interval (UI): 8.4 days to 3.7 years) for men and 1.5 years (95% UI: 6.8 days to 3.1 years) for women...".
When I read that, I know that that just means "if I'm building a probability distribution over the life expectancy of a person (who would be similar to the people studied, potentially including 'having not heard about this study') and I know how much TV they watch I can use that information to adjust my expectation based on this metric, as established by this well-founded study". However, "X reduced life expectancy" to normal people means "if I do X it will reduce my life expectancy, and if I avoid X, I can avoid that effect".
Let's say person A burns 1000 calories a day at his job, and only sits for a few hours when he goes home. Person B burns 1000 calories in his off time, but sits at work for 8 hours. Is person B still more likely to suffer health defects and die early? If so, why?