But yeah, Ann [Trason] insisted, running was romantic; and no, of course her friends didn't get it because they'd never broken through. For them, running was a miserable two miles motivated solely by size 6 jeans: get on the scale, get depressed, get your headphones on, and get it over with. But you can't muscle through a five-hour run that way; you have to relax into it, like easing your body into a hot bath, until it no longer resists the shock and begins to enjoy it.

I received the best advice for running I ever heard: 'You're not going to win, so just relax. If it feels like work, you're running too hard.

We've created an unnatural form of running. It's not just the shoes, but we run on artificial surfaces - straight ahead, hard and steady - instead of speeding up and slowing down, reacting to the terrain with changes of pace and rhythm.

That was the real secret of the Tarahumara: they'd never forgotten what it felt like to love running. They remembered that running was mankind's first fine art, our original act of inspired creation.

For nearly 2 million years, our ancestors survived and thrived and spread across the planet because they could run other mammals into heat exhaustion.

We say the rarajipari is the game of life, ' Angel said. 'You never know how hard it will be. You never know when it will end. You can't control it. You can only adjust.

He was onto something. Something huge. It wasn't just how to run; it was how to live, the essence of who we are as a species and what we're meant to be.