Here's where a lot of even very experienced ultrarunners fall short. They got to be what they are--quite competent at getting through a 50k or 100-mile race--by learning the arts of patience and mental toughness and by doggedly doing the mileage. Yet they run with handicaps and miss out on a big part of what could help them run faster and more enjoyably. Watch a random group of ultrarunners in action, and they look healthy, happy, gnarly, and game, but not especially athletic.
One of the great attractions of spectator sports like basketball or soccer, or of Olympic sports like gymnastics and swimming, is the wonder of the human body in motion. Arguably, there is nothing more beautiful on earth, because there is nothing more complex, and when all the complexities are in synch--in "the zone"--it's thrilling to watch. And, for the athlete, a thrill to experience. More generally, beyond sport, it's this most amazing of nature's wonders that gives us the pleasures of dancing and the integration of body movement with music.
Running will be more enjoyable--and your performances more satisfying--if you practice your movement the way a swimmer or basketball player or dancer does.
First, as you run, your body should be vertical, not leaning forward. For generations, cartoonists and logo designers have depicted running as an act of tilting forward, but in the real world that would result in falling down on your face. (The only exception is the start of a sprint, when gravity is actually employed as a momentary boost to initial forward propulsion for a few yards, with the legs moving at maximum anaerobic speed to "catch up" with the torso, and even then the sprinter is fully upright within ten yards.)
Second, it's important not to "cheat" on the verticality by sagging into a "C" shape, as many joggers and slower runners (especially older ones) do, with their heads appearing to be properly aligned over their feet but their butts and hips hanging behind them. The result is that while the C-shaped runner doesn't fall on his face, his lower torso is perpetually struggling to keep pace with his knees and chest, and there's no forward momentum. The way to remedy this is to focus on keeping your hips forward and your back straight, not slumped.
Third, your feet should point straight forward, so that you're not wasting energy or inviting injury with excessive lateral motion. Recreational runners can sometimes be spotted jogging with feet splayed so far outward that the knees are thrown inward--increasing the risk of injury to both feet and knees, not to mention expending so much energy that long-distance running would be out of the question except for a masochist.
Fourth, the arms should be swinging forward and back, fairly vertically like the body (not with elbows poking horizontally out to the side as if you were trying to elbow your way through a crowd), and fairly loose. Practice checking to make sure your shoulders are relaxed, not clenched.
Fifth, keep the head fairly still, not wobbling left and right as if tethered to the arms. The head is where the sense of balance is seated. While you're running on rough terrain, your legs and hips may make continuous complex movements to keep the balance, but it's the head's job to guide these movements by maintaining an independent, relatively unwavering forward track relative to the horizon.
These basics can't convey the real complexity of good running form, however. They can help you avoid or correct gross mistakes or misconceptions, but the best way to acquire good form may be simply to observe outstanding runners and--if you observe them enough--to subconsciously incorporate what they're doing into your own form. This is what kids do when they watch elite athletes in a stadium or on TV. High school basketball players have better moves today than they did half a century ago, not just because they're better coached, but because they've spent more hours watching NBA and NCAA games. That's not to say personal coaching by an expert in the biomechanics of running might not help, but simply watching great athletes can do wonders for getting your ancient running instincts activated. The best coaching you can get might be watching videos of great marathon runners or--if you can find them--ultrarunners like Scott Jurek, Ann Trason, or Michael Wardian.
--from an Appendix to The Longest Race: a Lifelong Runner, an Iconic Ultramarathon,
and the Case for Human Endurance, to be published in October.
Copyright 2012, Ed Ayres