Brian Resnick, Popular Mechanics (undated)
"Compared to other land mammals, humans are remarkably good at running long distances. Our upright posture and ability to shed heat—through sweating—are what allow people to run more than 20 miles during a race. Very few other animals can sustain such distances, especially at the speeds that top human athletes perform. But there is plenty of competition out there—nature is full of species adapted for running distance. Here's a look at six of the best marathoners in the animal kingdom, from slowest to fastest...."
"More than 20 miles? Make that 100-plus. The Lemming will get back to that.
This six-part slide show starts with horses:
"...Through years of selective breeding, racehorses have gained a built-in biological mechanism for efficient blood—the kind that certain human athletes can only achieve by doping. 'When they start to exercise, their spleen will kick out a whole bunch of red bloods cells into their system, into their cardiovascular system to make the oxygen carrying capacity of their blood go up,' says Peter Weyand, professor of physiology and biomechanics at Southern Methodist University....
"For the last 30 years, the Welsh town of Llanwrtyd Wells has hoted [!] a 22-mile, man-versus-horse race. Humans have only won the race twice, but top runners usually only finish 10 minutes after the animals. Where horses exceed in oxygen efficiency, humans make up for in temperature regulation. In the beginning of the race the horses tend to have a 30 minute lead, but toward the end, that advantaged is cut to a couple of minutes. Over the course of the race, humans are more efficient at expelling heat—not to mention they aren't running with a rider on their back. On a hot day, humans can win much more easily."
Yeah: a rider would slow a horse down. In principle. The photo showed riderless horses - which raised the question of what motivated the horses to keep going.
My guess is that if Llanwrtyd Wells extended their race a few miles, the horses wouldn't do nearly as well. They're wonderful animals: but, well, they're just not human.
The Lemming did a little research, about a year ago. Among other things, I compared winning times for two races that covered about 100 miles: one run by humans, the other by horses. The top human runners did just slightly better than the horse.
There's more to those numbers, though. The horses ran along an idyllic course: "flat with grassy and gravel surface. No hills, shaded." The humans? Our species decided that it'd be interesting to run 100.2 miles in the "Sierra mountains of California. ... cold, heat, mountains...." And the top runners still beat the horses.
The Popular Mechanics slide show has one page for humans:
"...One major difference between humans and animals is that we don't have in-born endurance; we have to train. Peter Weyand says that compared to other animals, humans have a high energy cost of running—we spend more energy in each stride relative to our size...."
On the other hand, we're really good at dumping heat. There's an 'up' side to the way we sweat. And - as the article points out - we can want to go faster, farther.
Then there's the ostrich: an improbable-looking bird with legs whose length is mostly tendon. That tendon acts like a rubber band or - as the article put it - pogo stick, storing energy when that leg hits the ground and releasing it later in the stroke. No wonder ostriches can average 30 miles an hour over a 20-mile course.
As for deciding that it'd be a good idea to have a long-distance endurance race over terrain like California's Sierras? Well, maybe someday we'll discover that homo sapiens sapiens is - crazy. I've discussed this possibility in another post. (December 5, 2009)
- "How Fast Can People Run? Depends on How Far"
(September 15, 2009)