In 2008, writer Christopher McDougall set out to tell the story of a little-known American ultrarunning fanatic named Micah True—a.k.a. Caballo Blanco—and his quest to organize a race to showcase the extraordinary running culture of Mexico’s Tarahumara Indians. Somewhere along the way the resulting book, 2009’s Born to Run, became a revolutionary bestseller, introducing the masses to barefoot running. McDougall has since become the barefoot movement’s de facto leader (actor Peter Sarsgaard plans to direct a movie version of Born to Run) and an outspoken critic of the athletic-footwear industry, which he accuses of peddling the false idea that running is dangerous unless you do it in excessively cushioned shoes. (“The entire multibillion-dollar industry is based on a campaign not of facts, but of fear,” he writes on ChrisMcDougall.com. “Fear that if you don’t buy a $175 sneaker and replace it in three months, you’ll ruin your knees.”) But his real mission, he told Christopher Keyes, isn’t to destroy the shoe companies. He wants to change the way we run.

Congratulations, you’re now the most influential runner in America.
[Laughs.] That’s the sorry state of American running.

Well, isn’t it true? You’ve certainly changed the footwear industry.
I’d love to just scoop all the chips off the table and claim they’re mine, but the truth is that while I was working on the book, I felt like I was paddling into a big wave. Millions of people were in the same predicament I was in, just wanting to jog a couple of miles without getting hurt. If Born to Run hadn’t come out in 2009, something else would have come out in 2010.

Now you’re the movement’s top evangelizer, and not a reluctant one.
I try not to make it be about me, but as with all evangelizers, something transforms you and changes your life—you see people saying things that are dangerous, and it’s hard not to speak up. I'm very glad, though, that I wrote the book at a time when I was still discovering barefoot myself, as opposed to now, when I'd probably be much more foamy-mouthed and lighting Molotov cocktails.

Why is barefoot running so polarizing?
Once you’ve bought into something, it’s very difficult to hear that it’s useless. When I first made the switch, I had three new pairs of $120 Nike Vomeros. That’s $400 worth of shoes. I wanted desperately to believe that they were fine. And what you’re hearing just seems wrong. How can running barefoot be better than running on a nice cushioned shoe?

You’ve been critical of the footwear industry for promoting that idea.
I was talking to a guy yesterday about the Brooks Cascadia, and my head was spinning. He was like, “Well, I got the Cascadia 6, and I think I’m gonna get the 7, but I don’t know about the 5.” And I’m like, “Dude, what the fuck? It’s all the same thing! Every six months they put a new number on it.” A little protection is fine; it’s when we got into the whole business of correction that things went askew.

Now every manufacturer has a minimalist shoe. Wouldn’t you call that progress?
A lot of these new shoes are excellent. But I see people wearing them and they’re still running the same way. And so the message is “buy” when what it should be is “learn.”

What do you think of the news that Vibram is being sued for making too many promises about its FiveFinger shoes?
It’s kind of frivolous. Why aren’t they filing the same lawsuit against the manufacturers of traditional shoes that have been making the same claims for 40 years? I know some of the Vibram people. I like them. I think they live what they sell. On the other hand, I don’t want to let them off the hook for playing the same marketing game all the other shoe manufacturers play. It’s possible they might have been suggesting more than they can prove.