At each Olympics, the winner of the 100 meters becomes known as the fastest man in the world. The race lasts a tad over 9 seconds, but it requires tremendous physical and mental preparation. It's not unusual for an elite sprinter to engage a scientist to analyze the biomechanics of his gait. But as NPR's Tom Goldman reports, at race time simplicity is best. Top runners say they are able to clear their minds of extraneous thoughts during their races.