For years, shoe companies competed over who could provide runners with the very best in arch support, heel cushioning and motion control. But now some runners are throwing away their shoes altogether and embracing a trend as old as running itself.

The current movement toward barefoot running was launched by author Christopher McDougall, who spent time with a tribe of Indians in Mexico. He was amazed by the way the Tarahumara (tare-uh-hoo-mare-uh) people could run ultra-long distances at high speed while wearing little or no footwear. From his research, McDougall speculated that modern shoe design actually causes injuries because it has changed the way people run.

Science supports his claims. According to a study published in the journal Nature, barefoot runners are more likely to land on the front, springy part of the foot as opposed to the heel-first strike common amongst shod runners. The scientists concluded that barefoot runners who strike the ground in the front of the foot generate smaller collision forces — or impact — than runners who wear shoes. The journal article also found barefoot runners have a springier step and use their calf and foot muscles more efficiently.

But don’t throw away your Nikes just yet. Most doctors say we still don’t know enough about the long-term impact of barefoot running to make a good judgment call. If you’re eager to give it a try, most experts recommend starting slowly with a pair of minimalist running shoes. There are plenty on the market today, thanks to the popularity of this trend. Also, barefoot running means more than just taking off your shoes. Because this method completely changes a runner’s stride, it should be treated as a skill and approached with care.

So tread carefully when you ditch your sneakers for bare feet.