Why is it that, although the human species is pretty pathetic when it comes to sprinting (just imagine Usain Bolt matching up with your average cheetah in an Olympic 100-meter final and you get the picture), we really rock as long-distance runners? In a long-enough distance race, a well-trained human can outrun just about any species on the planet.
Did we evolve to run long distances? There is certainly some compelling evidence to support this hypothesis. Daniel Lieberman, a paleoanthropologist at Harvard University, and Dennis Bramble, a biologist at the University of Utah, argue that many of the morphological and physiological characteristics of humans make us uniquely adapted to running long distances.
But if so, why are those of us who run for recreation or competition so prone to running-related injuries? If we are natural runners, shouldn't running come naturally to us? Nowadays, we have a plethora of fancy cushioned running shoe designs supposedly intended to alleviate all manner of running related ailments. Maybe you need a stability shoe for added support or perhaps a motion control shoe in order to avoid excessive pronation. It may seem logical that cushioning reduces the impact forces experienced while running but do they really? In fact although it seems counter intuitive there may be evidence to the contrary! At the same time there is no convincing evidence supporting the case that cushioned running shoes actually do anything to reduce the rate of running injury.
All of these issues are addressed in a fascinating new book published last week by journalist and ultra-marathon runner Christopher McDougall, entitled Born to Run. Being both a runner and a science professional, I couldn't put the book down. In Born to Run McDougall sets out on "an epic adventure that all began with one simple question -- why does my foot hurt?"
Inside, we follow the story of McDougall's attempt to answer that question. His search ultimately culminates in an underground fifty-mile trail race. Among the contestants are the author, a handful of world-class ultramarathon champions, a barefoot-running guru, an enigmatic loner, and the legendary Tarahumara Indians of Mexico's Copper Canyon. The Tarahumara are famous for being able to run incredible distances (up to hundreds of miles) in homemade sandals, and are seemingly immune to the multiple running injuries that plague the rest of us. McDougall also weaves in a fair amount of scientific research pertaining to running form, running shoes, and running injuries, ultimately leading us to question what in fact is the most natural way for us to run.
As you can see in the video above, Chris runs with short, quick strides. His feet land under his center of gravity, beneath his hips, and he strikes the ground towards the front part of his foot. While he does not seem to have the slight forward lean that we see in elite distance runners, he does look pretty light on his feet for such a big fellow. In Born to Run, we learn that this was not always the case. Previously a chronically injured backward-leaning heel-striker, Chris attributes his new efficient stride and lack of recent injury to his conversion to the barefoot school of running. (Those huarache sandals still count as barefoot running in that they don't provide any padding -- just a tougher skin on the bottom of the foot so to speak. It's the same with the Vibram Five Fingers Chris is pulling out at the end of the video -- a minimalist second skin to keep out stray shards of glass, thorny thistles, and the like.)
As a follow-up to my own recent posts on the science of running, I spoke with McDougall over the phone. After speaking with McDougall, at least one thing is clear to me: there really hasn't been a sufficiently thorough controlled scientific study to address this thought-provoking issue. Are most shoes actually doing more harm than good? Is it possible to design a shoe that allows for a natural barefoot-like gait, or is genuine barefoot running truly the best thing for your feet?
Over the past couple of weeks, I have done a little bit of (non-systematic) personal experimenting, running barefoot on grass and removing orthotics from my shoes during several of my weekly runs. Too early to draw any subjective conclusions!
Is it really true that overuse injuries are nonexistent among the Tarahumara?
As far as can be measured, yes. We see Tarahumara running into their 80s and 90s. The only running-related injuries they seem to get are things like broken legs due to falling.
[note: the Copper Canyons in Mexico are known to be incredibly treacherous and rugged, with vertiginously steep, rocky terrain.]
Why do you think this is?
The Tarahumara use their legs "as designed". By running at a young age with minimal footwear they naturally develop the best biomechanical use of their legs. Cushioned shoes restrict foot movements and allow for over-striding. Short strides are natural.
Elite athletes have light, fore-foot-to-mid-foot, efficient running form and yet they're still prone to injury -- not as much as recreational runners, but still. How are the Tarahumara different, do you think?
We've created an unnatural form of running. It's not just the shoes, but we run on artificial surfaces -- straight ahead, hard and steady -- instead of speeding up and slowing down, reacting to the terrain with changes of pace and rhythm. Also, runners who grew up barefoot have known fewer injuries. It's a testament to what's natural. Because people grow up with shoes they learn to run in an unnatural way.
So you're saying that a more natural stride is closer to a barefoot stride.
Can you tell us about your own attempts to alter your stride to be more natural?
When I started, I thought I was training wrong. I didn't think there was a right or wrong way to run. But Eric Orton, the coach I worked with, told me that there is a right way to run. We worked on it and altered my form beneficially.
Were you training barefoot? If not what kind of shoes were you using? Did it eliminate your injury problems?
Originally I didn't go to barefoot running, I started running in an early version of the Nike Pegasus, which has a pretty low heel and is relatively minimal. But then I started running a ton of miles -- up to one hundred and twenty miles a week -- and the heel pain really sank in. Then I went to a Pose Method guy. The Pose Method is a running technique based on a more natural stride. He showed me I was running the exact opposite of what I thought. I was leaning back and my feet were landing in front of my hips. The torso behind the foot led to torque and strain. With one adjustment, the heel pain went away. Now I run either barefoot or I use the Vibram Five Fingers. They have no cushioning. They're more like a glove for your foot. They hug the foot perfectly.
So now you've completely converted to barefoot running?
What about shoes that claim to simulate barefoot running, like the Nike Free?
Well, I wrote a story about the Nike Free, and I interviewed Barefoot Ted, who said they're nothing like barefooting. They're squishy on the foot, and they have an arch support and a padded heel.
[note: Barefoot Ted is one of the ultra runners in the book. He runs either barefoot or in the Vibrams. In fact, he is the first runner to be sponsored by Vibram.]
What do you see as the advantages versus risks of barefoot running?
Well the experts say you have to take your time to transition. I didn't. I ran six miles the first day and my Achilles [tendon] started hurting. But since then I've been free of injury. In minimalist running, you can't overtrain or overstride, because your feet will stop you. When you run barefoot you're not really pushing off, you're just tapping the ball of your foot down.
What kind of surfaces do you run on?
I run on all kinds of surfaces, from grass to dirt trails to asphalt.
You cite a study in your book that shows that more shoe cushioning actually results in higher impact forces - apparently due to the subconscious response of planting the foot harder in order to maintain balance on big squishy soles. What about orthotics for those of us with over-pronation problems? My feet seem to get tired when I don't wear the orthotics.
I think you're doing the opposite of what you should. Think about arches in buildings. They're weakened if you support them from underneath. Shouldn't that be the same with your feet? So where is the medicinal value of arch support? The problem is, things take time to develop and strengthen. Orthotics shortcut the process.
Okay, so you make a strong case advocating barefoot running as the best and most natural way to run -- the best way to remain free of injury (provided you take your time working into it). How do the shoe companies fit into all of this? Running shoes are all about support, stability, motion control etc. If none of this stuff works, what's happening here?
I have the idea that running shoes are based on a kind of cult idea -- that our feet are flawed and we need shoes to correct those flaws. The shoe companies are in the business of selling shoes. But there's no evidence from running shoe manufacturers that they're right. There's no scientific data that running shoes reduce injury.
Adam Weiner is the author of Don't Try This at Home! The Physics of Hollywood Movies.