Josh about to pass his grandpa

Josh about to pass his grandpa
Here, at age three, Josh regularly runs a mile or two with me--and I have to work hard to keep up!

Monday, March 21, 2011

Toes, Heels, and Human Evolution

     Maybe you heard the news of a study about the lengths of people's toes (seriously), a couple of years ago.  Published in the Journal of Experimental  Biology, it found that people who have short toes use a lot less energy to run, but not to walk, than people with long toes.  Also in the past few years, several popular books attracted attention to the Tarahumara Indians of Mexico's remote Copper Canyon, who run long distances barefoot or with minimal sandals.  I have the impression that both of these events have contributed to the growing popularity of the minimalist running shoe movement.  Remember when running shoe experts always advised us to allow an extra half-size of space in the toe box?  That, plus the sturdy toe box material itself, effectively made our toes longer.  If only I'd known!  Over three decades ago (in 1977 and 1980), I published four articles on the Tarahumara in Running Times. But in those days, most long-distance running was on roads, where there was often a lot of glass shards and trash, and barefoot running probably didn't sound like much fun.  Now, more of us run on trails, like the Tarahumara.
     OK, you might say, so the lengths of toes vary from one person to another, just as the lengths of our whole bodies do.  But why was that worth spending research money on, and why did it make headlines?  Would anyone pay grant money to study whether long-bodied (tall) people are more likely to be good basketball players?
     The answer is, the real signficance of this wasn't about comparing different groups of people, but about comparing people with other primates.  Humans have shorter toes than apes and other primates, but the implications of that weren't entirely clear until the energy-use discovery was reported by two anthropologists interested in human evolution--Campbell Rolan of the University of Calgary and Daniel Lieberman of Harvard.  Suddenly, a theory about human evolution that had been on the margins of academic paleoanthropology--the "persistence hunting" theory that humans evolved not as bipedal walkers but as bipedal long-distance runners--moved a little closer to being widely accepted.
     With the aid of hindsight, maybe I shouldn't have been surprised.  Over the past half-century, I've been through a whole odyssey of encounters with questions about how we runners should touch down and push off our feet, and what kinds of shoes we should wear--or not!
     My odyssey began with my first year of high-school cross-country in 1956, when my coach, who apparently had never been a runner himself, shouted repeatedly, "Run on your toes!  Run on your toes!"  I did, and it seemed to work out well.  Where he got that advice, I'm not sure.  Maybe it was one of those old chestnuts passed down from coach to coach, like "No pain, no gain!" (dead wrong) or "Never drink water during a hard workout" (dead wrong and deadly, but common belief in the 1950s).  Or, maybe he'd watched track meets and noticed that all the sprinters and quarter-milers ran on their forefeet (true).  In any case, I didn't question it and my running went well.
     But a few years later, I found one day that both of my feet were in extreme pain.  I went to an orthopedist, who told me I had collapsed my arches, would never be able to run again, and would have to wear full-lenth, rigid stainless steel arch supports in my shoes for the rest of my life.
     I liked running way too much to take that seriously, soon started running again (and wearing the steel arch supports only in my street shoes), and have run another 45 years without a break since then.  After about ten years I lost one of the steel supports, so I gladly threw away the other.  I replaced them with plastic orthotics--but again, only in my street shoes.  When I run, I want to feel the earth under me.
     I continued to run on my "toes" (landing on the forefoot) until 1965, I think it was, when I decided to do my first marathon--the Cherry Tree Marathon in the Bronx.  At around 17 miles, I caught up with a guy named Ted Corbitt, who'd been on the U.S. Olympic marathon team in the 1950s and was kind of a legend among the New York-area runners.  Ted had been one of the founders of the Road Runners Club of America, and is now remembered as the father of American ultrarunning.  By the mid-60s, he had slowed, but was still running road races and was a great inspiration to younger guys like me.  When I pulled even with him, I saw him glance at my feet.  Then he kind of smiled, and said, "You know, you'd probably run better if you let yourself land on your heels!"  I was awestruck; it was as if I were a Little League kid who'd suddenly been offered personal advice by Micky Mantle!
     Over the next four months, I took Ted Corbitt's advice to heart (or should I say "heart and sole"), and relaxed my gait, letting my feet touch down lightly on the heel, roll forward, and push off the forefoot.  In retrospect, I think that one sentence from Ted Corbitt probably extended my running life by 20 years.  Today, at age 69, I run much more mileage than I did in high school, and my feet feel as good now as they did at 16.
     Which brings me back to the study of toe-lengths.  I don't  know whether the researchers addressed the question of forefoot (toe) strike vs. heel  strike, and the rather important biomechanical difference between sprinting and long-distance running.  For a sprinter, long toes wouldn't be a handicap, at least as far as energy use goes.  You don't see a 200-meter guy stopping to grab a banana at the 100-meter aid station!  Even a 1500 meter runner is only going to use less than a tenth of the glycogen energy stored in his muscles, so he can run for maximum power rather than be concerned about energy conservation.  And indeed, as far as I know, all top middle-distance runners, as well as sprinters, are forefoot runners.  They take more energy, but also get more leverage and lift.  The design of a drag-race car doesn't care about MPG.
     And finally, that brings us back to the implication of short toes for the evolution of humans.  For decades, evolutionary scientists tended to dismiss this theory on the grounds that running could hardly be a survival advantage for early humans (hominids) because hominids were slower than all the animals they were chasing, or that might chase and kill them.  What the persistence-hunting theorists suggested was that when the slow-footed hominids chased a faster animal like an antelope, the animal would easily dash away but would soon tire and have to stop for rest.  The hominids were slower but had developed greater endurance, and would keep coming.  The quarry would dash away again, stop again . . . and after a series of such escapes would finally be too exhausted to continue, and the hominids would catch up and kill it with a rock. (We described the Tarahumara doing just this, in our 1977 articles.)  The Darwinian advantage for the humans, then, was not speed but endurance.
     To me, that fact has huge implications not just about the human past, but also about our future.  Right now, I think it's clear that humanity is in trouble.  In the increasingly hectic and often frantic rush of modern civilization, we have become infatuated with speed and power in all things.  As a consequence, we may be inadvertently abandoning the very qualities that enabled us to be good survivors--the qualities that brought us to the dance.  Part of my argument is that with endurance came other qualities essential to long-run survival: patience and ability to anticipate what the eyes cannot yet see.  I'm exploring this concern in a separate website,  Comments are welcome!




TrailRunner said...

Intriguing.....I enjoyed this as I am a tad obsessed with the tarahumara but also need shoes/orthotics to run distance. My podiatrist has said I won't ever be able to run barefoot or at least can't start as I'm near 40 years old and had I started as a youngster, I'd be ok to. The difference in gait, footstrike is so important and thanks for noting this. I strike too hard on my heels so I'm trying to change that.
Thanks again! Very informative!

Justin said...

Ed-Great post with solid insight. I have begun to change my gait from a heel striker to a mid-foot landing after reading "Born to Run". I have had bad knees (I'm 31) since my high school cross country days and wanted to run pain free. I bought a pair of five fingers and ran 6 miles right out of the box. Ouch! I learned the hard way and had to take some time off. I then gradually implemented the barefoot running and the use of minimalist shoes. I have been running pain free for two straight years now and believe its is because of my forefoot landings.

I am astonished at you accomplishments. Congrats and run till you can't run anymore.

asheley said...

thoroughly enjoyed this post!