Folgendes fand ich gerade auf einer Nachrichtenseite im Internet, mit Datum 2.10.:

(HealthScout News) -- If you're a runner, you should know that baring your sole can be a sign of strength.
Many professional runners and serious amateurs run several miles a week without shoes, reports the sports physician for Stanford University's track and cross-country teams in Palo Alto, Calif. "The support we get from our shoes is a good thing most of the time, particularly when we're running on asphalt or harder surfaces," Dr.
Michael Fredericson says "But many shoes provide so much support that the foot muscles will weaken over time."
Running barefoot, he says, keeps the muscles toned and elastic. That's particularly helpful in preventing Achilles tendonitis and other conditions marked by heel pain and often related to muscle tightness in the calves and feet.
Casual runners should try running barefoot once or twice a week for several hundred yards. Find a grassy surface and carefully check it for hazards such as broken glass before you run.