With so much interest in running for good health, is it better to do so barefoot? Are there any improvements to be had by doffing shoes while on the track?
"There's no question that you can run barefoot and be extremely healthy," says Daniel Lieberman, who studies the evolution of human anatomy at Harvard University. "Clearly, our feet evolved to run barefoot."
Indeed, sneakers are a rather recent development. And so are pavements. Lieberman further notes that orthotic inserts may actually make our feet weaker.
Previous research has shown that running barefoot requires less energy, and runners tend to land with less force on their heels. Some also suggest that barefoot running may result in fewer injuries.
However, few studies of barefoot runners exist. And many of the studies only examined people who regularly wore shoes, but removed them just for the experiment, says Lieberman. Given this limitation, he is now conducting research with people who are accustomed to running without shoes to see whether or not it's beneficial.
Even without conclusive research, some runners just prefer to go barefoot. Web sites devoted to going sans shoes cite benefits, such as fewer injuries, while others insist that it's just more natural.
Many people agree that running barefoot should really be approached cautiously.
"In principle," says Benno Nigg, who studies biomechanics at the University of Calgary and also says that he works with shoe companies, "the idea to strengthen those muscles is very good."
Nevertheless, runners who want to try it barefoot should start off slowly. Run on soft surfaces like grass for only a few minutes at a time.
Stephen Pribut, a private-practice podiatrist in Washington, D.C., shows some of his patients how to boost their foot muscles by picking up a towel with their toes.
However, he maintains that "you're not going to un-pronate your foot by exercising any muscle in your foot."
Over-pronation -- or excessive rolling inward of the foot -- happens because of bone structure, he explains. In other words, some biomechanical problems will not be corrected by strengthening the feet.
Pribut, who also sits on the board of advisers for Runner's World magazine and is a former president of the American Academy of Podiatric Sports Medicine, suggests that only runners with a certain arch shape should attempt running barefoot.
"Some people's feet are just built for needing guidance" from shoes, like people with low arches, he explains.
Bruce Williams, a private-practice podiatrist in Indiana and also a former president of the American Academy of Podiatric Sports Medicine, makes it a point to sound a note of caution: "I just think there's a lot of hype out there over barefoot running."