Loathe jogging? Harvard prof explains how humans evolved to be couch potatoes

NEW YORK — Daniel E. Lieberman wants people to stop getting worked up about exercise.

In his new book, “Exercised: Why Something We Never Evolved to Do is Healthy and Rewarding,” the Harvard University evolutionary biologist explains how scheduling time to do voluntary physical activity for health’s sake is a relatively new phenomenon. And, he says, there’s no shame in preferring to lounge about rather than lace up a pair of running shoes.

“I really love to run — it’s rewarding for me. But people shouldn’t feel ashamed for not wanting to exercise. We didn’t evolve to exercise. It’s like if you put a chocolate cake in front of me I’m going to want to eat it. That’s instinct,” Lieberman said. “It doesn’t mean I should give in to that all the time, or I’m going to get into [health] trouble. But I’m also not going to beat myself up for enjoying a slice now and again.”

Lieberman was inspired to write the book while doing fieldwork in northern Mexico with the Tarahumara people, who are known for long-distance running. He’d arrived there two weeks after watching the Ironman Championships in Hawaii. Expecting to see bare-footed people sprinting hither and yon, he was puzzled when he saw people casually walking about, or even sitting. So he asked some of the Tarahumara how they train. He was met with incredulity — they didn’t understand why anybody would run if they didn’t have to.

It was an “aha!” moment, Lieberman said.

“It’s just something we don’t think about, but it’s my job to talk about how we in the world have changed the way we use our bodies,” he said. “There are all kinds of things we do that we take for granted, like reading — we think reading is totally normal, but it isn’t. Nobody read until a few thousand years ago. It’s a completely modern thing.”

Drawing from his own research and extensive and up-close and personal experiences around the world, Lieberman tackles some myths and inaccuracies about physical fitness and advises readers on getting motivated. Along the way, he unravels how and why people evolved to walk, run, dig and fight — but also how they evolved to sleep, relax and sit.

In the prologue, Lieberman describes himself as having been “a pint-sized, nerdy kid,” who was picked last for teams in school and how in first grade he once hid in a closet during gym. Today he’s an avid runner who competes in marathons, says he’s adding more weights to his routine, and, while he’s not a religious man, recommends people follow the advice in Deuteronomy to take a day of rest.

The Times of Israel spoke to a cheerful and energetic Lieberman via Zoom on a cold January afternoon. The following interview was edited for brevity and clarity.

The Times of Israel: In your book you say that shame and guilt are counter-productive when it comes to encouraging people to move, and that the “just do it” message frequently backfires.

Lieberman: I invented that term “exercist” — people who nag and brag and make others feel bad. There is a lot of virtue signaling through exercise. All those people with the 26.2-mile bumper sticker, what’s that about?

There is a lot of virtue signaling through exercise. All those people with the 26.2-mile bumper sticker, what’s that about?

Eighty percent of Americans don’t get the recommended amount of physical activity, which is 150 minutes a week. That’s not a lot. So evidently our medicalized, commercialized, commodified approach is not working for a lot of people.

I think hopefully what people will feel when they read this book is that they understand that little voice that tells them to stay on the couch. We all have that little voice. It’s instinct not to do unnecessary, discretionary exertion. You shouldn’t feel bad about that, but that doesn’t mean you should give in to that voice all the time.

Can you tell us a bit about Jean-Jacques Rousseau’s theory of the “noble savage” and how it continues to negatively permeate perceptions about athletic ability?

It’s what I call the myth of the “athletic savage.” It dates back to a lot of racist ideas. The idea that the descendants of slaves didn’t feel as much pain as Europeans — that’s a really horrible way of thinking.

Back in the 1930s, the fastest runners in the world were from Finland, such as Pavao Nurmi. But, to my knowledge, no one was saying, “Gee, what makes Finns the best runners? What genes do they have?”

Now you have all these fantastic runners from Kenya and Ethiopia, and everybody wants to know what genes they have that make them better. I’m sorry, but I think there is a kind of racism there. It’s like people are trying to find excuses to explain why Africans are dominant over Europeans. I find that really troubling.

You contrasted the long-distance Tarahumaran running game rarajipari, which you called a form of prayer, with Ironman Triathlons, where people participate to test their limits. But many runners run to achieve a runner’s high or to empty their minds. Isn’t that a form of spirituality?

Absolutely.

Part of the point of that comparison was to say the Ironman is commercial and Western, with all these people who have fancy shoes and gear, while the Tarahumara are traditional and the event is part of their culture. But in many ways the races are similar. The Tarahumara have their form of Gatorade and cheering. They bet like wild over the races. I think the similarities are as important as the differences.

I don’t think most Ironman competitors are doing it because they think it’s a form of prayer, but anybody who does ultra-endurance sports knows you can get those trance-like states, so I can see why there’s a spiritual element to it. I’m not a religious person, and I feel that way when I’m doing a marathon.

The chapter “Inactivity: The Importance of Being Lazy” opens with a quote from Deuteronomy about resting on the Sabbath. It then describes how because the first Jews were subsistence farmers, it would have been unlikely they observed the Day of Rest as we know it today. What should we make of this?

The argument I was trying to make in that chapter is that everything is a trade-off when energy is limited. If you’re spending energy on one thing, you’re not spending energy on another. Rest is an important and beneficial physiological function.

By the way, I don’t think it’s a coincidence that it’s also a mitzvah [commandment] to procreate on the Sabbath. I kind of joked about that at the end of the chapter. I didn’t say that explicitly, but because on the Sabbath you’re not spending that energy tilling your fields, you can now spend that energy on the only thing natural selection cares about.

I don’t think it’s a coincidence that it’s also a mitzvah [commandment] to procreate on the Sabbath… because on the Sabbath you’re not spending that energy tilling your fields, you can now spend that energy on the only thing natural selection cares about

Many of us marveled at former Supreme Court justice Ruth Bader Ginsberg’s exercise regime, which she continued into her late 80s. What can we learn from her?

I think this is the most important part of the book. The worst time to become physically less active is as we age. In the book I talk about the Harvard alumni study, which showed that Harvard alums in their 70s have 50% lower death rates than people of the same age who don’t exercise.

Exercise turns on the repair and maintenance mechanisms in our bodies, so the older we get, the more important it is for our health. It’s also true that when you exercise there is risk of injury or falling, so you have to be careful. When I run now, I don’t run on icy pavement because I’m afraid of falling. I’m not a spring chicken, so if I fall, I’ll be in trouble. But that doesn’t mean I’m not exercising.

Ruth Bader Ginsburg was a very vivid demonstration of that principle. Exercise is not a magic bullet — it won’t prevent you from dying, but it sure does keep you healthy and vigorous up until the end.

If we’re to believe the articles of the past couple of years, our chairs are death traps and if we work at a standing desk we’ll be Olympics-ready in no time.

That’s another example of how we oversimplify health information. It’s true, too much sitting is bad for you. However, I’m not going to demonize sitting, or claim that it’s this weird, strange thing that only Westerners do. Other people sit as much as we do.

There’s a reason why I titled the book “Exercised.” People are exercised about health and physical activity because of the shallow way that so much information gets presented. We do need to be active and we shouldn’t sit for hours and hours and hours. I just think we can convey that without saying your chair is going to kill you.

We do need to be active and we shouldn’t sit for hours and hours and hours. I just think we can convey that without saying your chair is going to kill you

Why is the focus on elite athletes and elite athletics harmful?

Elite athletes show us how training, passion and dedication can lead to extraordinary skills and inspirational performances. So I’m not opposed to elite athletics. But I think we should step back and ask, “What does it have to do with the rest of us?”

Most of us don’t spend years training to run as fast as we can from one line to another line a certain distance away, or to throw a ball through a hoop. I worry that you might think if you can’t run a mile in four minutes you’ll say what’s the point.

Look, there’s no way I can run a mile in four minutes, or five minutes, not even six. I’m slow! But I’m in my 50s and I don’t really care. However, if you’re a young kid it’s different. The emphasis on competitiveness, which can be good, can also be off-putting. We should think about finding ways to encourage people to be active, even if they’re not performing at some spectacular level.

On a scale of 1 to 10, what was harder for you: carrying water on your head like you did in Kenya, tracking musk oxen and kudu in Greenland and Tanzania, or running in Boston in the winter?

Oh my gosh, carrying water on my head was by far the hardest of all. It’s really hard to carry that much weight on your head. It’s an incredible skill and I’m just not good at it.