PROVO — Considering the switch from regular sneakers to a minimalist pair? Brigham Young University researchers have shed light on the barefoot running trend and advise newbies to transition slowly to avoid injury.

“You just want to get your feet used to the lack of cushion and the lack of support,” said Sarah Ridge, a professor in BYU’s exercise science department.

The 10-week study followed two groups of experienced runners as one group transitioned into minimalist running shoes and the other stuck with their normal sneakers. When the researchers compared the before and after MRI’s, they found a notable trend: a higher percentage of runners in the experimental group saw increases in bone marrow edema, or inflammation in the bone caused by excess fluid, which can lead to stress fractures.

“Some marrow edema is totally normal under a typical loading circumstance,” Ridge said. “Basically what happens is you place load on the bone by impacting. When your foot hits the ground when you’re running there’s an impact, so the bone is loaded.”

The bones generally respond by getting stronger, as long as the increase in impact is gradual enough. However, problems arise when the load is increased by too much too soon.

“You have too (much) impact but not enough time for your body to recover,” Ridge said. “Then you get increasing amounts of bone marrow edema. That’s a precursor to something like a stress fracture.”

The athletes kept logs in which they recorded their mileage and any pain they experienced during the transition, following a schedule outlined for transitioning runners by the minimalist shoe companies.

“I think the idea was just to try to design a study around a typical person who would buy a shoe and (follow) the advice of the company and the website and the salespeople,” said Doug Brown, the radiologist who analyzed the runners’ MRI’s.

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Slightly more women than men had exceptional levels of bone marrow edema at the end of the experiment, but the research team, also including Wayne Johnson, Iain Hunter and Ulrike Mitchell, said the trend wasn’t statistically significant in this particular study. That facet will have to be explored in subsequent research.

There are many people who have jumped on the minimalist shoe train and haven’t experienced any injuries, but researchers still recommend following a gradual plan to avoid problems. Athletes can still make the switch but should take plenty of time.

“We’re not saying barefoot running is bad,” said Mitchell, an assistant professor of exercise science. “We’re just saying that if you transition into barefoot running, you probably need more than 10 weeks.”