We are the biggest sissies in the jungle. Every other animal is stronger than we are - they have fangs, they have claws, they have nimbleness, they have speed. We think Usain Bolt is fast - Usain Bolt can get his ass kicked by a squirrel.

The Tarahumara would party like this all night, then rouse themselves the next morning to face off in a running race that could last not two miles, not two hours, but two full days. According to the Mexican historian Francisco Almada, a Tarahumara champion once ran 435 miles, the equivalent of setting out for a jog in New York City and not stopping till you were closing in on Detroit.

Humans are built for endurance, not speed. We're awful sprinters compared to every other animal. We try to run our races as if they were speed races, but they are not. They're endurance races. Even a marathon, the way it's run now, it's not an endurance contest.

Were designed for persistence hunting, which is a mix of running and walking. Whats built into that kind of running is a sense of pleasure. You are designed and built and perfect for this activity, and it should be enjoyable and fun.

Faced with the almost inescapable conclusion that it had been selling lemons, Nike shifted into make-lemonade mode. Jeff Pisciotta became head of a top-secret and seemingly impossible project: finding a way to make a buck off a naked foot.

I have the idea that running shoes are based on a kind of cult idea - that our feet are flawed and we need shoes to correct those flaws. The shoe companies are in the business of selling shoes. But there's no evidence from running shoe manufacturers that they're right. There's no scientific data that running shoes reduce injury.

Distance running was revered because it was indispensable; it was the way we survived and thrived and spread across the planet. You ran to eat and to avoid being eaten; you ran to find a mate and impress her, and with her you ran off to start a new life together. You had to love running, or you wouldn't live to love anything else. And like everything else we love-everything we sentimentally call our 'passions' and 'desires'-it's really an encoded ancestral necessity. We were born to run; we were born because we run.