Sports: April 2009 Archives

 

April 21, 2009

This Boston Globe article covers the growing interest in minimalist running shoes:
That's right. Running shoes are a failed experiment. After nearly four decades of technological gimmicks and outrageous prices, they simply do not perform the function that's their only reason for existence -- protecting your feet. You can now buy running shoes with steel bedsprings embedded in the soles or with microchips that adjust the cushioning, but the injury rate hasn't decreased in almost 40 years. It's actually inched up; Achilles' tendon problems have risen by 10 percent since the '70s.

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So how do the Tarahumara, running in shoes that barely qualify as shoes, do it? Three years ago, I trekked into the Copper Canyons of Mexico in search of the secret. And once I learned how to run barefoot-style -- landing on the balls of the feet, while keeping my feet directly under my hips -- like the Tarahumara, my ailments suddenly disappeared. Plantar fasciitis, Achilles tendinitis, sore knees -- all gone. Today, I wear something similar to a rubber glove for the foot (it has the thinnest of soles to guard against abrasions), and I haven't looked back.

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But the unmistakable fact is that there's a trend across the shoe industry toward creating more "minimal" shoes -- those intended to duplicate the experience of, you guessed it, running barefoot. Still, those models just aren't simple enough

I'm not sure I buy this set of arguments, especially the one about injury rates. I hate to keep promulgating homeostasis theories, but I think there's some relevance here. Certainly, if you're an elite athlete you're going to train as hard as you can, which basically means that you keep ramping up the intensity and volume until either (1) you run out of time to train (2) you get injured or (3) you get so overtrained you can't keep jacking up the training level. So, even if you suddenly had better injury prevention technology, you wouldn't expect the injury rate to change that much. I don't have any empirical evidence here, but if you compare performances in the 70s to performances today, they've improved really dramatically: even in the marathon, which was very competitive in the 70s, the WR has come down by almost 5 minutes (~4%) since 1969. If you look at something like the Ironman, times have come down over an hour (more than 10%) since the 1980s. I suspect a lot of that improvement is that people are training harder. I don't know to what, if any extent this is pulling the average person's training load up.

This isn't to say that I'm convinced that modern running shoes improve the situation: the Inov-8 trail shoes I've been running in lately are deliberately unstructured, and even just wearing Injinjis rather than ordinary socks feels like your feet are more flexible and less constrained. I'm certainly enjoying training in them, and my long-term ankle injuries seem better. On the other hand, the one time I tried running a significant distance on road on them, I started to worry about how much impact I was putting into my legs. After all, we didn't evolve to run on asphalt either. Lately I've also been trying out Sanuks, which are basically sandals attached to a soft nylon shoe upper. Like Inov-8s the theory seems to be that they're not really going to support your foot. There does seem to be some kind of impact from this little support: the first few days my legs hurt but then I adapted. I don't have any reason to believe it's for the better, though. At some point I'll need to check out the research on this topic.

What I'm really interested in trying, though, is the new Vibram FiveFingers shoes, which are basically a rubber-soled sock. It's pretty clear you need to try them on to get the fit right, but Zombie Runner claims they're getting them soon so hopefully I'll be able to try them and report back.