By Chris McDougall
Published: 7:00AM GMT 12 Jan 2010
(photo by Luis Escobar)
Science and sceptical runners are catching up with something the Tarahumara Indians have known for ever: your naked feet are fine on their own. According to a growing body of clinical research, those expensive running shoes you've been relying on may be worse than useless: they could be causing the very injuries they're supposed to prevent.
Perhaps the best research in the field has been going on for hundreds of years in a maze of canyons in northern Mexico. There, the reclusive Tarahumara tribe routinely engage in races of 150 miles or more, the equivalent of running the London Marathon six times in the same day.
Despite this extreme mileage, as I learnt during several treks into the canyons, the Tarahumara are somehow immune to the injuries that plague the rest of the running world.
Out here in the non-Tarahumara world, where we have access to the best in sports medicine, training innovations and footwear, up to 90 per cent of all marathoners are injured every year.
The Tarahumara, by contrast, remain spry and healthy deep into old age. I saw numerous men
and women in their seventies loping up steep, cliffside switchbacks on their way to villages 30 miles away. Back in 1994, a Tarahumara man ventured out of the canyons to compete against an elite field of runners at the Leadville Trail Ultramarathon, a 100-mile race through the Rocky Mountains. He wore homemade sandals. He was 55 years old. He won.
So how do the Tarahumara protect their legs from all that pounding? Simple – they don't. They
don't protect and, most critically, they don't pound. When the Tarahumara aren't barefoot, they wear nothing more cushioned than thin, hard sandals fashioned from discarded tire treads and leather thongs. In place of artificial shock
absorption, they rely on an ancient running technique that creates a naturally gentle landing. Unlike the vast majority of modern runners, who come down heavily on their foam-covered heels and roll forward off their toes, the Tarahumara land lightly on their forefeet and bend their knees, as you would if you jumped from a chair.
This ingenious, easy-to-learn style could have a profound effect on runners, not to mention the multi-billion dollar running-shoe industry. Ever since Nike created the modern running shoe in the Seventies, new joggers have been repeatedly warned that their first step should be through the door of a speciality store. Without proper footwear, they're told, crippling injuries are inevitable. Take this recent comment by Dr Lewis G Maharam, "the world's premier running physician" as he's known, and medical director for the New York City Marathon. "In 95 per cent of the population or higher, running barefoot will land you in my office," Maharam said. That's because only "a very small number of people are biomechanically perfect."
Shortly before the New York City Marathon, David Willey, the editor of Runner's World magazine, broadcast a similarly dire warning on the radio. "If a lot of runners or all the runners out there in America did that tomorrow [ran without shoes], the vast majority of them would get hurt very quickly and would have to stop running for a long time." And why? Because, Willey said, "the vast majority of people are not blessed in that way. They've got some biomechanical inefficiencies."
This logic has at least one major flaw: the vast majority of runners, "blessed" or otherwise, are getting hurt anyway. The injury rate among all runners has hovered somewhere between 60 and 80 per cent for the past 40 years. You'd expect casualties to decrease as technology improved, but you'd be wrong: there are more heel and Achilles' tendon injuries now than ever, even though Adidas sells a trainer with a microprocessor in the sole to customise cushioning, and Asics spent $3 million, and eight years – three more than it took the Manhattan Project to create the first atomic bomb – to invent the awe-inspiring "Kinsei", a shoe that boasts "multi-angled forefoot gel pods" and an "infinitely adaptable heel component".
Astonishingly, there's no evidence that any of this technology does anything, which may explain why Nike ads never explain what, exactly, those $190 shoes are supposed to do. In a 2008 research paper for the British Journal of Sports Medicine, Dr Craig Richards, a physician at the University of Newcastle in Australia, revealed that after scouring 30 years' worth of studies, he couldn't find a single one that demonstrated that running shoes made you less prone to injury.
So if shoes aren't the solution, could they be the problem? That's what Dr Daniel Lieberman, the head of the evolutionary anthropology department at Harvard, began to wonder. Humans, after all, are the only creatures that voluntarily cover their feet, and we're also the only creatures known to suffer from corns, bunions, hammer-toes and heel pain.
Last spring, Lieberman recruited Harvard students for an experiment: he had them kick off their sneakers and run every day in either bare feet or wearing a thin, rubber foot-glove called the Vibram Fivefingers. The results were remarkable. Once their shoes were taken away, the students instinctively stopped clumping down on their heels. Instead, they began landing lightly on the balls of their feet, keeping their feet beneath their hips and bending at the knees and ankles. Without knowing it, they were mirroring the Tarahumara.
Lieberman was so taken by his discovery that before long, he was startling undergraduates by loping past them in bare feet for miles at a time through the streets of suburban Boston.
In Germany, meanwhile, the world's leading researcher in human connective tissue, Dr Robert Schleip at the University of Ulm, began a similar experiment to see whether he could end his own battle with plantar fasciitis, a vexing heel pain that is almost impossible to cure fully.
"If you encase the foot in thick shoes," Schleip says, "you not only lose ground awareness, you limit your natural elasticity." Schleip began slipping out of his shoes to run barefoot through the parks of Berlin. Soon, his heel pain vanished, never to return.
So harmful are running shoes that you're better off walking in high heels. That's the conclusion of a study published this month in PM&R, the journal for the American Academy of Physical Medicine and Rehabilitation. A team of researchers put 68 young adult runners on a treadmill, and found that they suffered 38 per cent more twisting in their knees and ankles when wearing shoes than they did in bare feet.
"Remarkably, the effect of running shoes on knee joint torques," the lead researcher said, "is even greater than the effect that was reported earlier of high-heeled shoes during walking."
Similarly, a study in The Journal of Sports Medicine and Physical Fitness in March 2009 found that even when running on hard surfaces, barefoot runners experience less impact than runners with shoes because – as the Harvard students discovered – they naturally take shorter strides and bend their knees and ankles. No one needed to feed those numbers to Abebe Bikila, the two-time Olympic champion, or Zola Budd, who held the
5,000 metre world record and competed for Britain in the 1984 Los Angeles Games: both preferred running in bare feet.
Sceptics like to argue that runners bring injuries on themselves by doing their miles on hard, man-made surfaces and being less athletic than marathoners of yore. That reasoning ignores the fact that barefoot humans got along quite well on hard terrain for two million years, running on cement-like surfaces like the sun-baked African savannah, the beaten-dirt trails of the Amazon, and the stony canyons of Mexico.
When it comes to novices, no one has more experience than the military and less margin for error. For centuries, armies have had to train out-of-shape recruits to cover marathon distances on their feet. Rather than dispensing plush trainers, the military took another route. As described in the classic military text The Soldier's Foot and the Military Shoe, all new recruits are taught to land lightly on the balls of their feet. They keep their feet under their hips, swinging their legs in a quick, light shuffle to a beat of 180 strides per minute – which, not surprisingly, exactly matches the ancient running rhythm of the Tarahumara.
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