One of the biggest myths about exercise is that it’s natural. If anything, human instincts lean more toward taking a nap. Want to feel bad about skipping a workout? Blame evolution.
Daniel E. Lieberman argues this theory in his new book “Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding,” which tips some of the fitness world’s most sacred cows. Everyone knows exercise is good for them, yet studies show most people don’t get enough of it. Mr. Lieberman set out to find out why, and the answers, he hopes, will help remove some of the shame people feel about their own inactivity that makes it even harder to get moving.
Mr. Lieberman criticizes people he calls “exercists” who brag about how much they work out and pass judgment on the less fit as unnaturally lazy. Those who take the escalator instead of the stairs are not guilty of the sin of sloth, he writes, but doing what they were evolved to do—saving energy only for what is necessary or recreational.
Other highlights from the book out Jan. 5: People who believe brutal cross-training workouts bring them closer to the brawny body that belonged to their ancient forebears probably are not familiar with research that shows Neanderthals were only slightly more muscular than today’s regular humans. Fitness buffs who think civilization’s pampering has muted our natural strength might not realize that a profoundly inactive couch potato moves more than a typical chimpanzee in a day. As for our natural talents, it bears noting that the average person runs as fast as a hippo.
Mr. Lieberman, 56, a professor of human evolutionary biology at Harvard University, helped popularize barefoot running in the U.S. after publishing a paper in Nature on how and why people ran barefoot before the invention of shoes. In this book, the biological anthropologist hails the benefits of fitness and recommends beating the anti-exercise instinct by working out with friends and making commitments like registering for a race. His philosophy: Any movement is an improvement on none, more is usually better, and it is never too late to start.
The 24-time marathoner recently spoke with The Wall Street Journal about why he’ll go running on the day he gets his Covid-19 vaccination, how standing desks don’t count as exercise and why a caveman would never do CrossFit.
I wonder how people who do high-intensity cardio with weight training will respond to this book. I feel like you’re calling out CrossFit in particular.
I guess I am. I’ve done some CrossFit workouts, they’re great. I’m not anti-CrossFit. But there’s this CrossFit mystique that your inner primal macho ripped hunter-gatherer ancestor, is who you were meant to be. If that gets you happy, that’s fine, all power to you, but you don’t have to make the rest of us feel bad for not doing these intense crazy workouts. They’re not necessary.
You get this sense by reading some books or popular articles that those of us who are contaminated by civilization are somehow abnormal because we don’t want to get out of bed and run an ultramarathon or go to the gym and lift 300 pounds. Our ancestors never did that and they would think it’s crazy because they were struggling to survive with limited food.
[Editor’s note: A CrossFit spokesperson said the program is designed for functional fitness across daily activities, like lifting the kids or playing sports, rather than strength alone.]
From an evolutionary standpoint, how do you explain people who love to exercise?
It’s not that we don’t have rewards for being physically active. Our brain produces this wonderful mix of chemicals that makes us glad we’ve exercised. The sad part of the equation is that our brain doesn’t create these chemicals to get us to exercise. We’ve turned something normal and simple and basic into a virtue signaling thing.
It’s like people who are intolerant of other people’s weight. Most people in America are now overweight. They’re not overweight because of some fault of their own and they’re struggling, and yet there are people out there who are unacceptably mean to people who are struggling. I think we need to have the same level of compassion toward people who are struggling to exercise. There’s nothing wrong with them.
Do you disagree with those who call sitting the new smoking?
Let’s relax. The chair is not the enemy. It is true that when people are not exercising—or being physically active generally—it’s because they’re sitting. If you look at the data, work-time sitting is not strongly associated with negative health outcomes, but it’s leisure-time sitting that is, because if you sit in the morning and then sit in the evening then you’re not getting any exercise. If you went to visit a hunter-gatherer tribe in Africa that doesn’t even own chairs, they’re sitting as much as we are, 9 to 10 hours a day.
Does that mean standing desks are not worth it?
There’s almost no data on that, so the answer is nobody really knows. There’s nothing wrong with standing desks. I actually have a standing desk and am standing while talking to you. But it’s not a form of exercise. Interrupted sitting or more active sitting—kneeling, squatting sometimes, also standing—does turn your metabolism on a little bit. You’re spending maybe an extra eight calories an hour standing. The point is that if you sit for a bunch of hours a day and you’re not sitting petrified and completely immobile, you’re not going to kill yourself.
What have you learned about exercise and Covid-19?
The evidence is pretty clear that physical activity does help reduce people’s vulnerability to a wide range of respiratory tract infections. Of course there’s no data yet on this for Covid, but for some other immunizations there’s evidence that if you exercise the day you have an immunization, you have a better antibody response.
So will you exercise on the day you get the Covid vaccine?
I can’t wait. Yes, of course.
Write to Ellen Gamerman at [email protected]
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