Exam “practiced”: born to run?

Doctors, fitness gurus, and the media keep reminding us that exercise leads to healthier, longer lives and leaner, more attractive bodies. We celebrate feats of athletic prowess and a prodigious focus on superhero actors with almost pathologically severed torsos. So why, if all of this is so good for us, do most of us have relationships with exercise that range from love-hate to hate-hate? Why do we rely on cutting edge surveillance technologies like smartwatches to challenge us in the “required” daily pace?

The title “Exercised” is a clue: there is something neurotic, upset, worrying about our obsession with physical activity. In the book, Mr. Lieberman confronts a dozen fitness and health myths, devoting a chapter to each. His focus is evolution – he’s a Harvard paleoanthropologist with a specialty in human locomotion – and he studies the effects of energy-spending body movements in the lab and in various groups of people around the world.

In one chapter, for example, Mr. Lieberman discusses the myth that sitting is bad for you. Disappointingly, he finds the myth to be true, but not the way most people assume. Contrary to popular belief, slouching postures do not lead to back pain, as evidenced by both the extensive research on office workers and the comparisons of sitting styles around the world. The real problem is that people don’t get up and move around enough. As scientists are beginning to understand, long-term inactivity and the increased amount of fat around our organs increases the risk of chronic inflammatory diseases, like arthritis and type 2 diabetes. Mr. Lieberman’s prescription? Do not stay inert for too long. Take a break. Get up. Or at least “shamelessly squirm”.

Until about two million years ago, each of our ancestors lived on the search for wild foods. Human physiology and anatomy have adapted to these ancient lifestyles in ways that may not be optimal today. It’s not that we’re worse off for this story – indeed, Americans in the 21st century are living longer and healthier lives than those in any other era. But sometimes the tricks we have developed to solve old problems cause us to stumble today.

To understand the challenges of modern life, anthropologists rely on the observations of the few human groups who live by searching for unarmed wild foods. Some of the best parts of “Exercised” are Mr. Lieberman’s accounts of his work and that of others with these modern foraging groups, like the Hadza people, who inhabit a barren and relatively inaccessible corner of Tanzania. Their days include a few hours of physical activity finding food, digging tubers, hunting and collecting honey. The Hadza spend much of their time sitting and socializing. Like other foraging peoples living on subsistence diets, they find Westerners’ obsession with exercise bizarre.

Anthropologists are wary of overgeneralization of data from Hadza and other populations, as all of today’s gatherers are integrated into the global economy in complex ways. Mr. Lieberman is candid about this challenge, recounting how scientific research itself has become a cottage industry supporting the Hadza community. The worst risk is that individual research observations will be turned into scientific stories, what Lieberman calls the “myth of the athletic savage”.

On this point, “Exercise” makes significant progress in the area of ​​research for which Mr. Lieberman himself is best known – the physiology of running. In the early 2000s, Mr. Lieberman collected some skeletal traces of ancient Man standing and physiological data from human runners to suggest that endurance running was part of what made us human. The idea was that ancient hunters used a slow but steady running pattern to track animals and chase them until exhaustion.

In “Exercise,” Mr. Lieberman visits a group of people who have inspired his current research, the Tarahumara people of northern Mexico. The group was made famous in the 2009 book “Born to Run” by Christopher McDougall, which introduced the story of their ultramarathon races to a wide audience. In “Exercised”, Mr. Lieberman describes his visit to observe a traditional Tarahumara running race. He marvels at a counterintuitive observation: Tarahumara who run do not train for them. Long runs are infrequent social events that bring the community together, but relatively few people directly participate. Runners’ experiences are similar to ultramarathoners in the United States, with pain and exhaustion. But the cultural significance of the activity is distinct – it is less a competition than a “powerful form of prayer” which, for runners, “induces a state of spiritual trance” – making it difficult generalization of any notion of human origins.

A few passages of “Exercised” suffer from excessive focus on the calorie bottom line. For living and breathing animals, the balance of energy intake and expenditure is just as important as a company’s bottom line. Yet reducing the rich pageant of life to metabolic inputs and outputs tends to make human existence as dry as an accountant’s ledger. In that vein, my favorite part of the book is about dancing. In many societies, dance is a physical activity linked to ritual, a highly social activity with deep symbolic meaning for its participants. It reminds us that beauty, joy and rites of passage are central to human life and that physical activity can be exuberant and ecstatic.

For those hoping for a reason to hide in the closet during gym class, this isn’t your book. Science confirms in many ways that physical activity is valuable for healthy living. Nonetheless, I find Mr. Lieberman’s voice of moderation to be welcome in a world where barefoot running and paleo diets have become fashions. (“Make exercise necessary and fun,” he says. “Some are better than nothing. Keep going as you get older.”) Instead of looking to a mythological view of our evolutionary past, we should look around at a fan. larger than real humans, all moving – thankfully – through their lives. “Practice” is a start.

Mr. Hawks is professor of anthropology at the University of Wisconsin-Madison.