And according to a study by Lieberman in February’s issue of the journal Nature, the answer is “people seem to be born to run — barefoot.” The study found that running barefoot seems better for the feet because it produces far less impact stress compared to feet hampered by expensive running shoes.

People who grew up running barefoot (such as boys in Kenya’s Rift Valley province, which is known for endurance running champs) tend to land mostly on the front or middle of the foot when they touch ground. And when these runners do use shoes, they continue to run in that way, while people who have always worn cushioned running shoes usually hit the ground heel first.

The difference in the way the foot strikes the ground is important. People with running shoes strike the ground with the mass of the entire leg, nearly 7 percent of the body, which is more than three times the weight of impact for barefoot running.

For runners in cushioned shoes, “it is literally like someone hitting you on the heel with a hammer,” Lieberman said. But, he said that “the way in which barefoot runners run is more or less collision free.”

So, the next time you teens, or you twenty-/thirty-something, San Francisco runners take off for Golden Gate Park or maybe even the Golden Gate Bridge, leave your shoes at home and do as we, Baby Boomers, used to do before there were fancy running shoes, just go barefoot!

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