Before the Nikes, before the breathable, antimicrobial running shorts, before the personal fitness coaches, heart rate monitors, wrist-mounted GPS and subscriptions to Runner’s World, you were a runner. And, like all children, you ran barefoot. Now, a small but growing body of research suggests that barefoot is the way adults should run, too. So, many runners have been shucking off the high-tech trainers in favor of naked feet — or minimalist footwear like Nike Free, the Newton All-Weather Trainer and the glove-like Vibram FiveFingers.
“People have been running barefoot for millions of years and it has only been since 1972 that people have been wearing shoes with thick, synthetic heels,” said Daniel Lieberman, a professor of human evolutionary biology at Harvard University.
Strong evidence shows that thickly cushioned running shoes have done nothing to prevent injury in the 30-odd years since Nike founder Bill Bowerman invented them, researchers say. Some smaller, earlier studies suggest that running in shoes may increase the risk of ankle sprains, plantar fasciitis and other injuries. Runners who wear cheap running shoes have fewer injuries than those wearing expensive trainers. Meanwhile, injuries plague 20 to 80 percent of regular runners every year. But the jury’s still out on whether going barefoot is actually an improvement.
“The running shoe right now is doing nothing for preventing injuries,” said Reed Ferber, director of the Running Injury Clinic at the University of Calgary’s Faculty of Kinesiology. But, he adds, going barefoot has downsides too, and the research so far is still inconclusive. “It’s a total tradeoff.” Chris McDougall, author of the recent book Born to Run, goes further. “If this were a drug, it would be yanked off the market,” he said of running shoes. McDougall says his own persistent problems with plantar fasciitis cleared up after he started running in Vibram FiveFingers.
What’s so great about going shoeless? It allows the foot to flex and absorb shock, says Tony Post, president of Vibram USA, which makes FiveFingers. With thick heels, people lengthen their strides, landing heel-first and letting the shoe absorb the impact of each footfall. You can’t do that barefoot (try it sometime), so your body naturally falls into a shorter stride, landing first on the outside middle or ball of your foot. As you advance your foot rolls inward; the arch flattens and helps absorb the impact; it then springs back up as you lift your foot and push off the ground.
“In a sense the arch is acting like a leaf spring,” says Post. Lieberman’s research into human and early hominid fossils suggests that the human body, including the foot, is well-adapted to long-distance running without shoes (.pdf). He hypothesizes that early humans didn’t need speed so much as endurance — just enough to run down herd animals like kudu or eland until they collapsed from overheating. This so-called persistence hunting is not as hard as it sounds, Lieberman says. “You can be a middle-aged professor like me and still be a good enough runner to have been a fairly successful hunter in the Paleolithic.”
He’s sure that running barefoot or with minimal footwear is the way to avoid injury. After all, we evolved without shoes. “If a third of runners had gotten injured in the Paleolithic with runner’s knee or plantar fasciitis, you can bet that natural selection would have weeded them out,” Lieberman says. Ferber is more cautious. His studies of the biomechanics of running show that a midfoot strike does reduce the initial peak loading force — the impact in the first 25 milliseconds after your foot touches the ground. But your foot sustains a second peak load of three times your body weight about 100 milliseconds later, regardless of whether you’re a heel-first or midfoot-first runner.
“So it’s six of one, half dozen of the other, in that you’ve lost that first peak, which is maybe a good thing,” says Ferber. “But in order to do that midfoot strike, you have to take a shorter stride, so you’re taking more steps per mile. So that could cause injuries.” Ferber does note that knee osteoarthritis rates are very low in China, where many people wear flip-flops (which also encourage a midfoot strike), and that studies have shown women who wear high heels are at increased risk for knee osteoarthritis. That research doesn’t address running specifically, however.
As for efficiency, Ferber’s studies suggest a midfoot strike might be about 1 percent more efficient — but that’s within the 2 percent error rate of the sensors used to measure human body force, so it’s a wash. Both Ferber and Lieberman are in the midst of long-term studies aimed at producing more conclusive data about injury rates and efficiency of barefoot or nearly-barefoot running. Ferber’s lab is sponsored in part by SOLE, a shoe orthotics company, while Lieberman’s research is sponsored by Vibram.
The Vibram FiveFingers seem to have a special attraction to geeks, for whom claims of efficiency and scientific research resonate especially well. Silicon Valley entrepreneur Tim Ferriss wrote about the FiveFingers recently, calling them “nothing short of spectacular” in a blog post filled with technical and biomechanical references.
“For me the appeal is the radical minimalization of technology to serve its purpose (conditioning) better,” said Boston-based software designer Glenn McDonald, a self-described “not-very-serious runner” who wears FiveFingers on occasional runs. As a nerd and a runner myself, I could hardly let these claims go untested. So for the past month, I’ve been running once or twice a week in the Vibram FiveFingers KSO model, with occasional stints done completely barefoot. Following the advice of experts like Ferber and Barefoot Ken Bob, I started out gradually. To kick things off, I stopped in the middle of a four-mile run one dewy June morning, took off my running shoes, and did a half mile completely barefoot on a smooth, graded dirt path. It felt great, like getting a foot massage on the run. But my tender soles were stinging by the time I was done, and continued to sting for the rest of the day.
My second barefoot run, on asphalt, went more poorly: I tore up the tip of my fourth toe on the rough surface and spent the rest of my (shod) run bleeding into my sock. That was enough to make the attraction of Vibram’s foot gloves clear: They give you much of the feeling of running barefoot, and give the same workout to your arches, Achilles tendons and calves — except you don’t have to worry about injuries from rough terrain.
But by the end of the third week I’d worked up to three or four miles in the VFFs and nearly a mile at a time barefoot. My feet got tougher, but were still happier with the rubber covering, especially on rocky ground and asphalt. Each run felt better than the last, though it’s clear that my calves and my Achilles tendons in particular are not used to this kind of a workout. I suffered from sore tendons and, after one longer run, a sore ankle. That’s a common problem among runners who transition too quickly to barefoot or minimal footwear, says Ferber. He’s seeing many runners jump too enthusiastically into minimal footwear and develop plantar fasciitis as a result.
“Runners are insane — they don’t like to accommodate, they just like to do,” Ferber said. The key, Ferber says, is to build up ankle strength, transition slowly, and keep barefoot running — like other really taxing parts of training, such as hill work or speed work — to just 10 percent of your overall regimen. Despite the soreness, I enjoy running barefoot — or nearly barefoot. I’m building foot and calf muscles I never know I had, More than that, it just feels fun. And, truth be told, I enjoy the puzzled looks from the people I pass on the trail and the coworkers I terrorize with my freaky rubber gorilla feet.
“We’re designed for persistence hunting, which is a mix of running and walking,” says McDougall. “What’s built into that kind of running is a sense of pleasure. You are designed and built and perfect for this activity, and it should be enjoyable and fun.” So, like other nerds, I’ll probably keep happily running in the Vibrams, while eagerly awaiting the results from the next running shoe study.
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Source: http://www.wired.com/wiredscience/2009/07/barefoot/
Tags: Vibram 5 fingers, Nike, Nike Free, Newton All-Weather Trainer, the glove-like Vibram FiveFingers, Global Best Practice, Global IT News, Daniel Lieberman, professor of human evolutionary biology, Harvard University, Nike founder Bill Bowerman, Running Injury Clinic, University of Calgary’s Faculty of Kinesiology,
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