Like many runners, journalist Christopher McDougall got hurt. A lot. And like many of those injured runners, he was told that his aches and pains were a natural consequence of his chosen form of exercise. "Running," one doctor told him, "is your problem." McDougall didn't accept that—especially after reading about the Tarahumara Indians, who live in Mexico's Copper Canyons and run like stink, on shoes McDougall compares to flip-flops. He set out to learn from the Tarahumara. After years of research, he concluded that "persistence hunting"—a combination of tracking and endurance running over many miles at a time—was the human race's original, and best, form of exercise. He chronicles his journey of discovery in Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen (Alfred A. Knopf, $24.95). Here's an edited version of our conversation.
How strong is the evidence that we evolved to run long distances?
I'm really leery anytime someone pops up to say we evolved to do X. But [the idea of being evolved to run] is one piece that seems to snap into place and solve a lot of different paradoxes. Several things have been anomalies in sports and science for a lot of years. Why do women get stronger as distances get longer? When you look at a 100-meter dash, a marathon, and a 100-mile race, women go from being out of contention, to in contention, to winning.
Then there was a study done by scientists who tracked the averaging finishing time in marathons. They found if you start running at age 19, you get faster until you peak at 27 and then gradually get slower—but it takes decades for you to slow down until you're where you were when you were 19. Why do old people have the speed of younger ones? Why do women perform so well over long distances? It all tends to congregate on superendurance. These societies needed experienced guys who knew how to track, and young guys to kill the prey. And women with children had to be there, because they need protein the most.
Then there's the architecture of the human body. We are very specialized—we have a ligament in the back of our head [that keeps our head steady when we run]. We have the Achilles tendon [an anatomical spring] and big butts [that keep us from losing our balance when we run]. And when you come up against the Tarahumara, you start to see these weird things—no crime, no violence, no problems with high cholesterol, no depression, almost nonexistent cancer rates.
What makes the rest of us biologically different from the Tarahumara?
They're us, rid of fleshly indolence! They're genetically identical—they have nothing more or less than we have. The only difference is that they're much better practiced at using their stock parts.
A lot of people out there argue against aerobic exercise in favor of short sprints and strength training. Why is it such a heated debate?
People become attached to whatever they believe in. It's almost inarguable that distance running, as a starting point, is good. If you want to add in resistance training—sure! And as far as the way we do endurance sports, I agree [with the critics]. The way we measure how we run is to hit the stopwatch and go hard for two hours. When modern people try to use that technique in a persistence hunt, they collapse. But look at ultra runners. They walk up hills. When you're on a trail, the footing is unsure, you have to leap over trees. The terrain forces you to, on occasion, slow down. I suspect it's much more in line with how our bodies were designed to operate, never going into oxygen depletion or experiencing low sugar. The Tarahumara go very long on very little fuel. They're burning fats, not sugar. And they work as a team. There's this huge schism between running as something natural and this solitary thing you do yourself, as work.
Why were so many doctors eager to tell you that you weren't built to run?
I assumed the people who were giving me advice—running shoe people and doctors—knew what they were talking about. I can pin the tail on the villain and say they absorbed the party line of the sports shoe manufacturers who came up with the logical scenario that impact shock hurts. The disturbing thing is there's no evidence it's true.
So we don't need to go out and buy the most cushioned, expensive shoes?
We're being fleeced. It's a pure marketing and product thing. Modern running shoes let people run with their foot in front of their hips, picking up two feet of stride. You can't do that with the naked foot—it hurts. One of the mysteries out there is that if any shoe in existence really helped prevent injuries, you'd see that in an ad. But you don't. Over and over again, you're told you must go to a specialty running store. They'll say if you're doing something wrong, you need to buy something to fix it.
After I wrote this book I had heel pain. I couldn't shake it for a year and a half. I went to a barefoot running coach, and within 15 minutes the problem was solved. What had happened is that I'd started running with a neutral shoe and had regressed back to my old form—leaning back, landing on my mid-foot. That's what was causing the pain. I've been literally afraid to put on running shoes since then.
[Related: Read 3 Myths--and 1 Truth--About Running and Your Health. Check out our 10-Week Workout Routine. Or consider Paleo Diet: Can Our Caveman Ancestors Teach Us the Best Modern Diet?]