human urine is both nutrient-rich and an effective tooth whitener

Way before we were scratching pictures on caves or beating rhythms on hollow trees we were perfecting the art of combining our breath and mind and muscles into fluid self-propulsion over wild terrain.

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 got a motto here-you're tougher than you think you are, and you can do more than you think you can.

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.

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

Running should be free, man.