Why We Run – A Natural History

Why We Run – A Natural History
Bernd Heinrich, HarperCollins: NY, 2002

Ben Heinrich is a professor of biology at the University of Vermont and a former American champion and WR holder in the 100k ultramarathon.Why We Run is his autobiography, and a discursive tour through the natural history of animal endurance and human running.

Heinrich spends considerable time on his youth and the outlines of his path through life. An oddity to my eyes was the near-absence of anybody other than himself in this part of his story. We learn at various times he has at least one son, that he’s been divorced at least once, and that’s pretty much all. That’s the nature of some (though not all) autobiographies, but it leaves an odd feeling. On the other hand, he’s commendably modest about some of his academic achievements. Very, very few graduate students publish in Science (the journal of the American Association for the Advancement of Science, and with Britain’s Nature one of the two most prestigious science journals in the world).

Regarding the title topic – why we run – Heinrich’s hypotheses are (a) we evolved to be endurance runners; and (b) managing fuel and heat are the two biggest problems that have to be solved for any endurance animal (or insect). He’s persuasive on both counts, though in neither case is there a strong counter-hypothesis. That we evolved as endurance runners there can be no doubt.  Only a very small handful of land mammals (and one running bird) can run for the prolonged distances and periods of time we can, and such an extraordinary adaptation is extremely unlikely to be an accidental byproduct of some other, more important adaptation. And that fuel and heat management is crucial is again persuasive. One only has to look at fall-off in speed as fuel becomes an issue, and the temperature gradients and performances at races to be convinced. His argument that upright posture evolved at least partially as a heat dissipation strategy was new to me, and makes excellent sense.

While he’s right on both his major hypotheses, unfortunately he missed gravity, which is the dominant factor. His chapters on adaptations among insects and birds are interesting, but while at least birds’ biochemistry  matches ours, both birds and insects live with a radically different relationship to gravity than we do. (Though if anyone can figure out how to run up hills effortlessly by using thermals, please let me know.) Biomechanical efficiency in using energy – that is, how we relate to gravity – is the crucial factor in endurance running. We consume more fuel and dissipate heat better than feather-covered ostriches in north Africa or fur-covered kangaroos in the Australian outback, but both can run us into the ground as endurance athletes. Why? Because they’re far more efficient. Kangaroos feet apparently return about 95% of the energy of impact; ours return closer to 8%. So kangaroos have to re-accelerate 5% of their body weight per stride, and we have to re-accelerate 92%. Our relationship to gravity permeates all aspects of our beings, from our skeletal structure to our language.

I found it hard to accept much of Heinrich’s natural history. While I can’t doubt his accuracy about insects, I found myself skeptical about much of what he said about animals and humans. It’s frequent enough that he’s wrong (he gets both the name of the last Olympic 1500 meter champion and his time wrong – this in a book that has as its central fact Heinrich’s own time in a race). Sometimes he’s ignorant where one would think he wouldn’t be (he is the only running writer in the world to believe that training at altitude has no benefit for sea-level racing). Even within his professed interest, he spends a chapter on the camel, telling us that from camels we can learn that dealing with heat is important (!) On the other hand, he barely mentions the ostrich, which can run at 30 mph for hours, and he dismisses the kangaroo for poor heat dissipation, failing to mention empirical evidence that at least one kangaroo is known to have run more than 200 miles in 10 hours. (It was banded with a radio transmitter, and was recorded at one station in the morning, another 200 miles away 10 hours later – one might assume it, like my dog Iniki, probably didn’t travel in a dead straight line either.) Even little things are an annoyance. He describes throwing as a common human-chimp adaptation, apparently unaware that human shoulders have evolved to be significantly different structurally from all other primates (including chimps), specifically evolved for efficient throwing.

In addition, he hasn’t done his reading. He spends a number of pages theorizing about the role of big-game hunting in our evolutionary past, apparently unaware that this is a major topic of interest to anthropologists and evolutionary psychologists. Definitive studies on both protein availability and mating effects have established beyond much doubt the dominant role of women’s sexual choices in driving men to hunt big as opposed to far more plentiful small game. He’s coming up with a theory to explain facts that he has wrong in the first place.

And this isn’t an isolated case. As another example, he seems completely unaware of theories that our original adaptation to the savanna was as scavenging prey animals, not as predators until a good deal later in our evolutionary history. (Maybe that’s why we like relay races – an instinct to try to get away as a group?) Much of his theorizing about our running down prey takes on a different cast when considered as running away from predators. (And consider our adaptation for throwing – there’s a much bigger benefit in mediocre throwing for defense than offense.)

One more example. Heinrich seems to think that black Africa is a genetically homogeneous whole and that genetic inheritance has nothing to do with running ability. Africa in fact holds more genetic diversity than all the rest of the world combined, an odd thing for a professor of biology to be unaware of. And, if genetics aren’t a factor, why is it that no man who isn’t of central-west African descent has ever run 100 meters in under 10 seconds, that every single one of the top 200 men’s performances in the 100 meters is by a man of at least some central-west African descent? While to my knowledge a man of central-west African descent has never won a major distance title? Probably coincidence. While telling us that it has now been “proved” that the success of the Nandi subgroup of the Kalenjin subgroup of Kenyans runs exceptionally well because of their culture, he skips the part about the genetically similar highland Ethopians, who with a completely different culture also run exceptionally well. (Please note – I’m far from a genetic ‘determinist,’ but to say there is no effect at all just seems silly.)

Heinrich’s credibility suffers on another level. While describing the meticulous analysis and training he put himself through for his ultra, he offhandedly remarks that in stocking up for a particular ultra, he couldn’t distinguish between sugar-free cranberry juice and the normal stuff. Meticulous and spaced? That might apply to a runner who tried eating a quart of honey before a run to see how it would work (badly; not as bad as the time he drank a quart of olive oil, but worse that the time he took three six-packs of beer on a run).

With respect to ultrarunning itself, his approach is very much that of a hard-core competitive runner. This is as far from my own experience of ultrarunning as it can get, though to qualify that all of my ultras have been on trails, and I can’t imagine even for a moment doing one on roads, let alone a loop course in a city. Perhaps those are different; the strongest defining element of trail ultras is the intense sense that we’re all doing it together, the deep flow of mutual respect. At my first 50-miler, I remember watching the race winner jumping up and down and yelling for his friend finishing six hours later. If this is also Heinrich’s approach, it doesn’t come through in his writing.

This is still a good book, not nearly so bad as I’ve made it out. There is some fascinating stuff on how birds adapt to effective breathing at 35,000 ft for prolonged periods. There is much in it to admire, and at times Heinrich sinks into reveries about running and its effect on human well being that ring true for almost all of us.

Please follow and like us: