Suzanne's Mom's Blog

Did you ever wonder why you have to work so hard at exercise when for millennia, humans did OK with whatever movement was part of their normal day? Some folks say we’ve been overdoing things.

At National Public Radio (NPR), Terry Gross interviewed Daniel Lieberman, a professor in the department of human evolutionary biology at Harvard, about his new book on exercise. The interview relieved me of some preconceptions, but I didn’t see anything about getting the heart beat up.

“For much of history, human beings needed to be physically active every day in order to hunt or gather food — or to avoid becoming food themselves. … a professor in the department of human evolutionary biology at Harvard [says] that the notion of ‘getting exercise’ — movement just for movement’s sake — is a relatively new phenomenon in human history. …

“Lieberman says, ‘When I go to these [remote African tribal] villages, I’m the only person who gets up in the morning and goes for a run. And often they laugh at me.’…

“Lieberman has spent a lot of time with indigenous hunter-gatherers in Africa and Latin America, cataloging how much time they spend walking, running, lifting, carrying and sitting. He writes about his findings, as well as the importance of exercise and the myths surrounding it in his new book, Exercised.

” ‘If you actually look at what our ancestors do, they walk about 5 miles a day, which turns out to be, for most people, about 10,000 steps,’ Lieberman says.

“Lieberman notes that many people are moving less than they did before the pandemic. He says if 10,000 steps feels out of reach, it’s OK to shoot for less — just so long as you’re focused on movement. Even fidgeting can keep your muscles engaged.

‘The more we study physical activity, the more we realize that it doesn’t really matter what you do. You don’t have to do incredible strength training. … It’s all good in different ways.’

Prof. Daniel Lieberman

Interview Highlights
On the demonizing of sitting as “the new smoking”
“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. …

“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. …Then the numbers get a little bit scary.

On the importance of “interrupted sitting”
“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. … 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. …

“A seat back essentially makes sitting even more passive than just sitting on a bench or a stool because you lean against the seat back and you’re using even fewer muscles, even less effort to stabilize your upper body. And the result is that we end up having very weak backs. So there are a lot of muscles that we use in our backs to hold up our upper body, and those muscles, if we don’t use them, just like every other muscle in your body, they atrophy. And weak muscles then make us more prone to back pain. …

On the idea that running is bad for your knees
“There’s this kind of general idea out there that running is like driving your car too much, [but] study after study has shown that in terms of ‘wear’ — by which we really mean arthritis, degeneration of the cartilage in your joints — that people who run more are not more likely to get arthritis in their knees. … That said, it’s also true that the most common site of injury for runners is their knees. But a lot of those injuries, I think, are preventable by learning to run properly. …

On becoming frail with age
“One of the most important points about physical activity is that as we age, it becomes not less but more important to be physically active. Muscle atrophy is the perfect example. … We have plenty of evidence that older individuals in America are less physically active and they do fewer activities that involve strength. And one of the really sort of serious negative consequences of that is that our muscles dwindle, they atrophy. … That’s the bad news.

“But the good news is that it doesn’t take a huge amount of physical activity to kind of reverse that, turn it around. Think about Ruth Bader Ginsburg. She was celebrated for her vim and vigor, which meant that a lot of that came from the fact that she kept working out and as she got older, she went to the gym several times a week. Now, she didn’t do crazy. … She did a few rounds of weight training every week and that helped keep her marvelously active and vigorous up until her late 80s. “

Lots more advice at NPR, including how much sleep we actually need, here.

I better stand up now. I’ve been sitting more than 10 minutes.