Christopher McDougall, best known for his 2009 book Born to Run, wrote a piece a few days ago in the online version of The New York Times Magazine entitled The Once and Future Way To Run. The article largely covers the major themes of Mr. McDougall's book: that humans have been constructed by evolution to be long-distance runners; traditional running shoes cause injuries; and barefoot running forces people to run naturally. According to McDougall, the "once and future way to run' is the light, "whisper-soft" stride of the experienced barefoot runner.
Mr. McDougall practices what he preaches, having become a barefoot runner after travelling in 2008 to Copper Canyon, Mexico, home of the Tarahumara Indians. The experience "transformed" him from a "broken-down, middle-aged, ex-runner" into a runner capable of completing a 50-mile ultra-marathon over extremely rigorous terrain. The race is described in Born to Run, and regardless of your interest in barefoot running generally, I'd definitely recommend it.
In the subsequent two years since the book was published, barefoot running has become and remains a major topic of discussion in the running community, though admittedly less so these days than a year ago. People have argued themselves hoarse over the supposed benefits of ditching running shoes, adopting a fore-foot strike, and lessening impacts forces. It seems probable that this debate is one reason why the minimalist shoe industry has grown into a $1.7 billion dollar business. Regardless, the issue seems to warrant investigation.
In the article, Mr. McDougall cites a 2010 US Army Public Health Command report which concludes that running shoes, "'had little influence on injuries.'" Runners' World columnist Amby Burfoot came to similar conclusions in his 2010 review of the "Dismal Science" surrounding research on the running shoe question. In that review, Mr. Burfoot noted that the current research suggested that some shoes increased the amount of torque experienced by foot during exercise, but that the precise relationship between increased torque and increased injury incidence remained unclear. Without a clear-cut understanding of that relationship, Mr. Burfoot ultimately decides that runners could probably get away with a more minimal shoe than they currently use, but that it would be wise to experiment first.
Exercise physiologist Jack Daniels expressed a similar opinion in a video interview on the subject. Taking up the debate on whether a fore-foot, mid-foot, or rear-foot foot-strike is most effective for running, Daniels concludes from his research that the matter is unclear, but that individual mechanics appear to influence what type of foot-strike is most economical for each runner. It is entirely possible that a life-time heel-striker is actually more economical with a fore-foot strike, but that doesn't automatically make a fore-foot strike desirable for everyone. As with the running shoe question, careful experimentation currently appears to be the most sure what of determining what is optimal for particular individuals so far as foot-strike patterns are concerned.
In that vein, the barefoot vs. running shoe and fore-foot vs. heel-strike debates are but guides revealing a continuum of possibility in one's training. People have run quite fast without shoes (just look at Abebe Bikila in the 1960 Olympic Marathon). Furthermore, Jack Daniels points out in the video from above that in one study, it was found that adding 100g to the foot leads to a 1% decrease in performance (about 1 minute in a marathon). Given the physics of circular motion, the amount of torque required to move an object (one's leg and foot through a stride) increases with both distance and force ( Torque = radius x Force, or Torque = radius x [(mass)(acceleration)]), so having more mass further from one's body (i.e. 10 ounce running shoes on one's foot as opposed to just one's foot) requires more torque to move it. But there is also the question of receiving return energy from the shoe itself, such that while it costs more energy to move a shoe-clad foot, the benefits of the shoe may outweigh the additional cost in torque.
More research is required on this matter, and I suspect that because everyone's body is high individual, that individual experimentation is therefore the best means of determining whether you're more economical with or without shoes; fore-foot striking, mid-foot striking, or heel-striking. It could well be that how you run now is precisely how you ought to run to achieve optimal performance. But you'll never know for sure (so far as one can be sure) without a little experimentation. Due caution is, of course, advised.
Happy Friday, friends :)
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