very interesting research on persistence hunting, diet, technique...
lots of touching and inspiring stories - the tarahumara at leadville, czech olympian emil zapotek winning his first ever marathon, ultra runner scott jurek winning the badwater ultramarathon...
everyone thinks they know how to run, but it's really as nuanced as any other activity... ask most people and they'll say "people just run the way they run". that's ridiculous. does everyone just swim the way they swim? for every other sport, lessons are fundamental; you don't go out and start slashing away with a golf club or sliding down a mountain on skis until someone takes you through the steps and teaches you proper form. if not, inefficiency is guaranteed and injury is inevitable.
don't fight the trail... take what it gives you. if you have a choice between one step or two steps between rocks, take three.
think easy, light, smooth, and fast. you start with easy, because if that's all you got, that's not so bad. then work on light. make it effortless, like you don't give a shit how high the hill is or how far you've got to go. when you've practiced that so long that you forget you're practicing, you work on making it smooooooth. you won't have to worry about the last one – you get those three, and you'll be fast.