Some research says that too much sitting leads to an increased risk of obesity, diabetes, heart disease, a variety of cancers and an early death. You'll notice they do not say how much of an increased risk because in all likelihood the answer is unimpressively little. (A few numbers are given in this much shorter article.)
But the kicker to the research is this: Sitting for long periods is bad for you irrespective of whether you exercise vigorously. It's not simply that sitting is correlated with inactivity, it's that sitting (for long periods of time) is bad in itself.
Why? NYT's Opinionator:
The answer seems to have two parts. The first is that sitting is one of the most passive things you can do. You burn more energy by chewing gum or fidgeting than you do sitting still in a chair. Compared to sitting, standing in one place is hard work. To stand, you have to tense your leg muscles, and engage the muscles of your back and shoulders; while standing, you often shift from leg to leg. All of this burns energy. [...]
But it looks as though there’s a more sinister aspect to sitting, too. Several strands of evidence suggest that there’s a “physiology of inactivity”: that when you spend long periods sitting, your body actually does things that are bad for you.
OK, so there's that. Not unrelated is the calories thing:
If you sit for 30 minutes, you will burn 33 to 63 calories (for 110-lb. up to 216-lb. individuals). But standing for 30 minutes means burning 39 to 78 calories. So standing yields around 12 to 30 more calories per hour. For a full day of work (8 hours), standing might mean 96-240 more kcals used.
Another reason why I am biased toward standing is because Seth Roberts found that standing, especially on one foot, helped him achieve noticeably better sleep, waking up feeling "really good". I cannot say I have noticed the same thing, but I never had a problem with sleep to begin with, praise Buddha. (And, weirdly, now you can track my sleep patterns on Fitbit, you stalker.)
I'll give you two other little reasons why I prefer standing while reading:
1. I enjoy massaging the soles of my feet with tennis balls while standing.
2. Unlike sitting and reading, it's not easy to fall asleep while standing. Sitting and reading is a good thing to do when you're ready for bed.
So maybe after reading this post -- especially the part about premature death and the like -- you'll want to stand more often. If so, great. Just don't be too serious about it because having anxiety about sitting too much is likely to be at least as harmful as sitting too much.
And a word of advice: If you want to change your behavior, knowing that sitting is bad (or standing good) is not enough. Facts and statistics rarely cause lasting changes in behavior because they do not appeal to our emotional core. What appealed to my emotions (in fact, it was one of the first posts on this blog) was 2 seconds of a video here, showing the striking contrast of a cloudy vial of blood taken after a sitting meal versus a much clearer vial of blood taken from the same person after a standing meal.
And, by the way, I'm no standaholic. Most of my reading is done sitting at the computer. And even reading books, I spend more time reading in bed or reading sitting outside than I do reading standing up.
I'll leave you with two views from my favorite reading location, sitting:
