Nearly all runners do their slow runs too fast, and their fast runs too slow." Ken Mierke says. "So they're just training their bodies to burn sugar, which is the last thing a distance runner wants. You've got enough fat stored to run to California, so the more you train your body to burn fat instead of sugar, the longer your limited sugar tank is going to last." -The way to activate your fat-burning furnace is by staying below your aerobic threshold--your hard-breathing point--during your endurance runs.

Anyone can do running. Running should be easy. It should be fun. It should include everyone. It shouldn't be a punishment for eating cheesecake, which is what we've turned it into.

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.

There's something so universal about that sensation, the way running unites our two most primal impulses: fear and pleasure. We run when we're scared, we run when we're ecstatic, we run away from our problems and run around for a good time.

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.

Running is the heart of what it means to be human.

The 'Tarahumara' use their legs 'as designed.' By running at a young age with minimal footwear, they naturally develop the best biomechanical use of their legs. Cushioned shoes restrict foot movements and allow for over-striding. Short strides are natural.