In the meantime, a book recommendation: I really enjoyed Christopher McDougall's Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen. It is not, perhaps, quite as insanely compelling a book as Richard Askwith's Feet in the Clouds: A Tale of Fell Running and Obsession, but it is wonderfully good nonetheless - I couldn't put it down.
(I bought it, sight unseen, on Amby Burfoot's recommendation at the Runners World site, and was not disappointed.)
It is full of good things, including some fascinating and funny reflections on barefoot running and the Vibram five-fingers toe shoes. Here is a bit I especially liked, though it does not necessarily give the feel of the book as a whole, which is a sort of gonzo journalism-style excursion (think Hunter S. Thompson and Tom Wolfe) into the dangerous terrain of Mexico's Copper Canyons):
[Dr. Bramble] discovered that when many quadrupeds run, their internal organs slosh back and forth like water in a bathtub. Every time a cheetah's front feet hit the ground, its guts slam forward into the lungs, forcing out air. When it reaches out for the next stride, its innards slide rearward, sucking air back in. Adding that extra punch to their lung power, though, comes at a cost: it limits cheetahs to just one breath per stride.
Actually, Dr. Bramble was surprised to find that all running mammals are restricted to the same cycle of take-a-step, take-a-breath. In the entire world, he and David could only find one exception:
"When quadrupeds run, they get stuck in a one-breath-per-locomotion cycle," Dr. Bramble said. "But the human runners we tested never went one to one. They could pick from a number of different ratios, and generally preferred two to one." The reason we're free to pant to our heart's content is the same reason you need a shower on a summer day: we're the only mammals that shed most of our heat by sweating. All the pelt-covered creatures int he world cool off primarily by breathing, which locks their entire heat-regulating system to their lungs. But humans, with our millions of sweat glands, are the best air-cooled engine that evolution has ever put on the market.