I just listened to the NPR news item and podcast Just Move: Scientist Author Debunks Myths About Exercise And Sleep and Daniel Lieberman (professor, Human Evolutionary Biology at Harvard University) discusses their new book Exercised. and the transcript of highlights includes the following passage:
When I walk into a village in a remote part of the world where people don't have chairs or a hunter-gatherer camp, people are always sitting. ... Some friends and colleagues of mine actually put some accelerometers on some hunter-gatherers and found that they sit on average about 10 hours a day, which is pretty much the same amount of time Americans like me spend sitting.
So it turns out that I think we've kind of demonized sitting a little falsely. It's not unnatural or strange or weird to sit a lot, but it is problematic if, of course, that's all you do. As I started to explore the literature more, I was fascinated because most of the data that associates sitting a lot with poor health outcomes turns out to be leisure-time sitting. So if you look at how much time people spend sitting at work, it's not really that associated with heart disease or cancers or diabetes. But if you look at how much people sit when they're not at work, well, then the numbers get a little bit scary.
Background/context only: When I first heard "Sitting is the new smoking." I got worried because I sit and think/work for hours at a time without getting up. I get engrossed in thought and the "news" and popular press recommendations that we should get up every 15 or 30 minutes and go get a drink or something frustrated me because I love being engrossed in thought and I find it very productive and would find frequent interruptions of it deleterious to both joy and productivity.
That's what the author suggests as well:
Just getting up every once in a while, every 10 minutes or so — just to go to the bathroom or pet your dog or make yourself a cup of tea — even though you're not spending a lot of energy, you're turning on your muscles. And your muscles, of course, are the largest organ in your body — and just turning them on turns down inflammation. It uses up fats in your bloodstream and sugars in your bloodstream, and it produces molecules that turn down inflammation. So the evidence is that interrupted sitting is really the best way to sit. In hunter-gatherer camps, people are getting up every few minutes, to take care of the fire or take care of a kid or something like that. And that kind of interrupted sitting, as well as not sitting in a chair that's kind of nestling your body and preventing you from using any muscles, all that kind of keeps your muscles going and turns out to be a much healthier way to sit.
Question: So is the problem with long bouts of sitting that one is not "turning on my muscles" frequently enough throughout the day, and a separate daily bout of exercise doesn't make up for this? Are there still health risks like heart disease or cancer associated with long daily bouts of sitting independent of getting sufficient exercise including some aerobic exercise each day?