Book Argues That Humans Run Better Barefoot Than with Shoes
Tuesday, August 4, 2009
Imagine running 100 miles -- barefoot. Christopher McDougall believes that's what the human body is built to do.
In his best-selling new book, "Born to Run," McDougall argues that humans evolved for persistence hunting -- basically, chasing after game animals for hours until they keel over from overheating or exhaustion.
Can't imagine yourself outlasting an antelope on the savannah? Neither could McDougall before he began working on the book. In fact, he wasn't sure if he would ever be able to run again.
Five years ago the 47-year-old freelance writer took up running on dirt roads in Lancaster County, Pa., two or three miles every other day.
But what should have been healthful exercise left him with a catalogue of ailments. Like many runners, he saw pain as an unavoidable part of the sport, until he began reading up on the Tarahumara. Members of this reclusive tribe live in north-central Mexico, where they routinely run hundreds of miles through the harsh, rocky desert in flimsy sandals made from strips of tire rubber.
What really got McDougall, though, was that they do it smiling.
As he learned more about long-distance runners around the world, McDougall became convinced that these amazing athletes were living -- and running -- as nature intended.
Several intriguing lines of evidence, laid out in a 2004 Nature paper by University of Utah biologist Dennis Bramble and Harvard University biological anthropologist Daniel Lieberman, support McDougall's argument. Unlike other animals, they wrote, humans can dissipate heat on the run by sweating. And our breathing rhythm is independent of our stride, allowing us to breathe faster and get more oxygen into our bloodstream during exertion.
Other anatomical features -- short toes, the Achilles tendon, a head-stabilizing ligament absent in other primates -- also appear to be adaptations for running.
The "running man hypothesis" also helps explain a seeming paradox: Although young men leave women and older runners in the dust in short races and even marathons, when it comes to ultramarathons -- competitions that typically are 30 to 100 miles long -- the playing field becomes surprisingly level.
Since primitive humans hunted in packs, multiple individuals would have needed to maintain the same pace over a long distance to stay together, said McDougall. So it makes sense that everyone -- old, young, male and female -- would have similar long-distance running ability.
For natural-born runners, though, we hurt ourselves pretty often. According to a 2007 review paper published in the British Journal of Sports Medicine, up to 80 percent of runners suffer an injury each year. And despite major advances in running-shoe technology over the past three decades, injury rates have held steady or even increased.