‘Practiced’ Assessment: Born to Run?

Doctors, fitness gurus and the media constantly remind us that exercise leads to healthier and longer lives and thinner and more attractive bodies. We celebrate athletic achievements and lavish attention to superhero actors with almost pathologically cut 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 hectoring surveillance technologies like smartwatches to keep us doing our ‘required’ day-to-day business?

The title of “Practiced” is a clue: There’s something neurotic, irritated, anxious about our obsession with physical activity. In the book, Mr. Lieberman is confronted with a dozen myths about physical fitness and health, and devotes a chapter to each. His lens is evolution – he’s a Harvard paleoanthropologist with a specialty in human locomotion – and he studies the effects of energy-consuming body movements in the lab and on different groups of people around the world.

For example, in one chapter, Mr. Lieberman argues that sitting is bad for you. He finds it disappointing that the myth is true, but not as most people assume. Contrary to common practice, lanky postures do not lead to back pain, as shown by both much research on office workers and comparisons of seating styles around the world. The real problem is people don’t get up and move enough. As scientists are beginning to understand, prolonged inactivity and more fat around our organs increase the risk of diseases from chronic inflammation, such as arthritis and type 2 diabetes. Mr. Lieberman’s recipe? Don’t be inert for too long. Take a break. Stand up. Or at least “shamelessly squirm.”

Until about two million years ago, all our ancestors lived by foraging for wild foods. Human physiology and anatomy adapted to this ancient lifestyle in ways that may not be optimal today. It’s not that we’re worse off with this history – indeed, the Americans of the 21st century are living longer and healthier lives than those of any previous era. But sometimes the tricks we once developed to solve old problems stumble us today.

To understand the challenges of modern life, anthropologists rely on observations of the few human groups that live by foraging for wild, unarmed food. Some of the best parts of Exercised are Mr. Lieberman’s accounts of his and others’ work with these modern foraging groups, such as the Hadza people, who live in an arid, relatively inaccessible corner of Tanzania. Their days included a few hours of physical activity to find food, dig tubers, hunt, and collect honey. The Hadza spend much of their time sitting and socializing. Like other foraging people who live on a self-sufficient diet, they find Westerners’ obsession with exercise bizarre.

Anthropologists are wary of overgeneralizing data from the Hadza and other populations, as all contemporary collectors are integrated into the world economy in complicated ways. Mr. Lieberman is forthright about this challenge and talks about how scientific research itself has become a cottage industry that supports the Hadza community. The greatest risk is that individual research observations will be turned into scientific tall tales, what Mr. Lieberman calls the “myth of the athletic savage.”

In that regard, Exercised makes significant advances in the research topic for which Mr. Lieberman himself is best known – the physiology of human running. In the early 2000s, Mr. Lieberman collected some skeletal traces of antiquity Standing man and physiological data from human runners suggesting that endurance running was part of what made us human. The idea was that ancient hunters used a slow but steady gait to track animals and chase them to exhaustion.

In ‘Exercised’, Mr. Lieberman a group of people who inspired his research, the Tarahumara people of northern Mexico. The group became famous in Christopher McDougall’s 2009 book ‘Born to Run’, which brought the story of their ultramarathon-length 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 people who run races don’t train for them. The long races are rare social events that bring the community together, but relatively few people participate directly. The racers’ experiences are similar to those of ultra-marathon runners in the US, complete with suffering and exhaustion. But the cultural significance of the activity is clear – it is less of a competition than “ a powerful form of prayer ” that, for the runners, “ produces a spiritual trance-like state ” – making it difficult to generalize in any idea about the human origin.

A few passages of “Practiced” suffer from excessive focus on calorie expenditure. For live, breathing animals, the balance between energy intake and expenditure is just as important as the financial balance for a business. Still, reducing life’s rich procession to metabolic inflows and outflows tends to make human existence sound as dry as an accountant’s ledger. In that vein, my favorite passage in the book is about dancing. In many societies dance is a physical activity related to a ritual, a very social activity with deep symbolic meaning for the 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 is not your book. Science confirms many ways in which physical activity is valuable for a healthy life. Nevertheless, I find Mr. Lieberman’s moderate voice welcome in a world where barefoot running and paleo diets have become fads. (“Make exercise necessary and fun,” he says. “Some are better than none. Keep up the good work as you get older.”) Instead of looking at a mythological view of our evolutionary past, we should look around us to a wider range of real people, all moving – happily – through their lives. Getting “moved” is a start.

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