Given that we were built to run, it's curious how complicated we've made the business of going for a jog. Let's keep it simple: Running properly has nothing to do with what you put (or don't put) on your feet or what surface you run on and everything to do with maintaining perfect form.
Where and how your feet hit the ground is crucial. Most of us land on our heels, which creates a shock of up to three times our body weight, increasing the likelihood of repetitive-stress injuries. Daniel E. Lieberman, a professor of human evolutionary biology at Harvard, discovered that runners who landed on the front part of their feet, barefoot or not, suffered less than half the injuries heel strikers did. "It's about how your body moves, not what's on your feet," he says. "Good swimming requires you to learn good form—people don't throw you in the pool and expect you to swim properly. But for some reason we have this idea that everyone has their own natural running form."
Christopher McDougall's 2009 best seller, Born to Run, inspired a barefoot-running craze with its depictions of the Tarahumara Indians, who can run 150 miles without rest. "I went most of my adult life without ever hearing anything about technique," says McDougall, who transformed his own running capabilities by studying the Tarahumara. "Once you focus on mechanics, you're not in pain, you can go farther, faster. It's about posture, breathing, connection between mind, muscle, and ground contact. It's freeing."
Terrence Mahon, the founder of Mammoth Track Club in Mammoth Lakes, California, which trains Olympic runners and beginners, says learning proper technique is simple: "Most kids have ideal form. They land mid-foot, they don't lean from the hips, and they have shorter strides. You need to get back to that." What follows is Mahon's cheat sheet to perfecting your gait ("8 Steps to Perfect Running Form"). Go slow and experiment with the new form until it feels comfortable.