Meb Keflezighi Versus A Horse


Anyone who follows distance running knows that American Meb Keflezighi, Olympic silver medalist and winner of the New York and Boston Marathons, is a phenomenal athlete.  But few people know he can outrun a horse.  Here’s how.

Unlike horses and most other animals, humans can sweat.  This is of critical importance to endurance running because sweating prevents overheating.  Most mammals are dependent upon panting to cool themselves.  But panting occurs by taking shallow breaths at about ten times the usual rate of breathing.  This is a problem for galloping mammals because they have 1:1 coupling of locomotion with respiration to satisfy their oxygen demands.  Therefore, galloping mammals cannot pant and quickly become overheated.  This is dramatic in the case of sprinting cheetahs, which are famously fast but must stop due to overheating after approximately 1 kilometer.  Horses, of course, gallop much faster than humans can sprint, but they also have to slow down to prevent overheating after about 10-15 minutes.

[Since this article was published, I have been informed my sources were incorrect and that horses do, indeed, sweat.  Thank you for the correction, Julie Moffitt. However, the overall fact remains that humans do cool much more efficiently than other mammals, including horses.]

The speed of a galloping horse is approximately 30 mph (48 km/h), whereas the speed of a trotting horse (the sustainable speed for a horse) is approximately 8-12 mph (13-19 km/h).  I have limited experience with horses, but my expectation is that in a Meb vs Horse race, the horse either would have to gallop then trot slowly or gallop slowly then trot normally, to prevent overheating. This would be especially true in warm weather conditions.

The speed Meb Keflezighi maintained over his 2 hour, 8 minute, 37 second victory in the Boston Marathon in 2014 was 12.2 mph (19.7 km/h).  So, on paper, Meb vs Horse is simple algebra.

Assuming that the horse is able to gallop at full speed for 15 minutes then maintain a trot of 17.5 km/hour and that Meb is able to maintain his speed throughout, he will catch the horse in 3.22 hours.  If Meb slows down 5% because of added distance and the horse is like Gandalf’s Shadowfax and does not slow down, he catches the horse in 5.82 hours.

But you don’t have to take my word for it.  The “Whole Earth Man vs. Horse Marathon” has been held in Wales every year since 1980.  Here is a quote from the website of this event:

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The Man v Horse Marathon began in June 1980 following a chat over a pint (or three) in the back bar of Neuadd Arms Hotel. The then Landlord, Gordon Green overheard two men discussing the relative merits of men and horses running over mountainous terrain. The enterprising Gordon, never one to miss an opportunity to promote Llanwrtyd Wells and improve business at his hotel, decided to put it to the test. And so began Green Events and its first, longest standing and now internationally acclaimed event, The Man versus Horse Marathon.

Humans have won the race twice over that time (and a total of three humans were faster than their equine competitors).

In 2014, the winner, Leo the horse, won in 2:22:53 with an average pace of 14.84 km/h. Meb, sadly for the running universe, was not in this race.  Fortunately, we have access to the “Chrissie Wellington-conversion factor.”  Chrissie is a legendary multiple Ironman World Championship winner and for reasons that only she understands, participated in Man vs Horse in 2014.  Her fastest Ironman marathon (there are no stand-alone marathon results to compare) was 2:44:35 in the 2011 Challenge Roth in Germany.  This makes her speed about 15.4 km/h.  In the Man vs Horse Marathon in 2014, she ran 73.5% slower at 11.3 km/h.  If Meb’s fastest marathon performance (yes, it is a stand-alone and, therefore, different from an Ironman) were slowed by a similar 73.5%, his pace in Man vs Horse would be about 14.5 km/h.  Very close to Leo the horse.  Also, Man vs Horse is run over 23.6 miles (shorter than the standard 26.2 miles of a marathon) and over rough cross-country terrain.  This shorter, more challenging course would likely favor the panting horse over the sweating man.

There is another, smaller, event in Prescott, Arizona called “Man Against Horse.” Results are only available online for the past eight years.  In these results, humans were unable to win until finally beating the horses in 2014.  In that year, in fact, in the 25 mile event, there were three humans who were faster than the fastest horse.  In the 50 mile event, one human was faster than the fastest horse.

[Since this article was published, it was pointed out to me that the 100 mile Western States Endurance Run started out in 1974 as a horse event.  Humans then started to participate and, eventually, horses stopped participating.  Please see the comments attached to this article for more details. Thank you Cal Nef!]

So, on a good day, Meb could probably beat a horse in a marathon.  If the weather is hot, his ability to withstand overheating would give him an additional advantage over his equine competitor.  If Meb could not overtake a horse by the end of a marathon, he almost certainly would over a greater distance.

Go Meb!


Bramble DM and Lieberman DE. Endurance running and the evolution of Homo. Nature 2004 Nov;432:345-352.

Carrier DR. The energetic paradox of human running and hominid evolution. Curr Anthropol. 1984;25(4):483-495.

Heglund NC and Taylor CR. Speed, stride frequency and energy cost per stride: how do they change with body size and gait? J Exp Biol. 1988 Sep;138:301-318.

Lieberman DE, Bramble DM, Raichlen DA, et al. Brains, brawn, and the evolution of human endurance running capabilities. In: Grine , Fleagle , Richard , Leakey , editors. The First Humans—Origin and Early Evolution of the Genus Homo. Springer; 2006.

Minetti AE. Physiology: efficiency of equine express postal systems. Nature 2003 Dec;426:785-786.

Photo Credit: N06/4261515603/”>JPB93 via Compfight cc

4 thoughts on “Meb Keflezighi Versus A Horse

  1. Cal Neff

    There’s another man vs. horse race that predates (1974) Whole Earth, although the horses no longer run, a little event called Western States 100… the world’s oldest and most prestigious 100 mile trail race.

  2. Fidelito

    You’re right on to point out that the vast majority of women’s pairactpition in road races didn’t occur until after the 70s, and that he conviently forgets Meb, Deena and Kristy. What about all of the charities that have benefitted from road races? He also manages to forget that until the 70s the runners wore next to nothing on their feet and post-1970 the majority have been told they need to run in huge padded shoes, resulting (and I know the jury is still out on this one) in an increase in running injuries. And one last thing, while the average time of a marathon is longer than the 1970s, the winners of these marathons are posting times faster than ever seen before.


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