"It's like having a tire with a nail in it." —Nike's top coach, on heel-striking

If two of America's greatest runners can get healthy by getting off their heels, why shouldn't you? Three years ago, Alan Webb was one of the world's best milers. In 2007, he ran the fastest time in the world in both the mile and 1500 meters. Then he began to get injured and sank into a slump. Recently, as the Portland Tribune reports, he put himself into the hands of Alberto Salazar, the distance running legend who's now head of Nike's elite training program. And one of Salazar's first...