Marathon: It's not all about the shoe

In the first two World Marathon Majors of 2026, 19 of the 20 top five finishers across both the men's and women's races were East African. That is 95 per cent.

Zoom out further, and the percentages maintain a relative hold. 93 percent of the top 50 fastest marathon times ever run by men, and 86 percent by women, have come from athletes of East African descent.

This pattern has held, almost without interruption, for nearly sixty years, and at some point, such a streak stops looking like coincidence and starts demanding an explanation.

At Loughborough University in the United Kingdom, which is ranked the world's best institution for sports subjects for ten consecutive years, three sports PhD candidates – Utpal, Jess and Ben – each shared varied explanations:

1.  "Surely it is genetics and training."
2. "I see they are usually super skinny and toned, which must help them run easier."
3.  "I’m thinking more role models than anything else."

Different Opinions 

What do Kenyans think is the reason for this dominance?

Susan Kanyuga, an ultramarathoner who runs with We Run Nairobi, the city's largest run club, points to the familiar trinity.

"Genetics, particularly in the Rift Valley region, then altitude, especially in Iten. And of course, running to school every day from a young age," said Kanyuga.

Jonathan Tuzo, On Running’s ambassador for Kenya, who is currently chasing 26 marathons in 2026, sees it differently.

"I think we are mentally strong around pain and consistency. Kenyan runners have a high tolerance for discomfort. It might be we are used to tough situations, and that even when training is tough, it just feels normal," said Tuzo.

Brian Komen, son of the legendary Daniel Komen and founder of 720 Elite Performance, gives a layered answer.

"When young, I just thought we were born like this," said Brian.

His view today, after years inside the elite training ecosystem, is more nuanced and points towards something unique – togetherness.

"In the camps, athletes win together and lose together. They don't see each other as competitors. They share information freely, generation to generation. The competitive edge in shoes and sponsorships might create some friction, but at the core, they are family," Brian said.

It is a striking observation and a compelling one.

When Sabastian Sawe broke the two-hour barrier in London last month, John Korir, the 2026 Boston Marathon champion, was filmed jumping and cheering back home. Athletes whose entire livelihoods depend on beating each other openly celebrate one another's success. That kind of generosity is rare in elite sport, and it may itself be a cultural inheritance.

Peter Kogo, a running coach based in Kapsabet, brings the perspective of someone who watches new generations of talent emerge each year. He lists his factors in a manner to suggest he has been thinking about this for a while.

"First is genetically built; that is, lean, tall and lanky. Secondly is the childhood activity of herding cows and walking long distances daily. Third is diet, where milk gives the bones sufficient calcium through childhood, and the food is low in fat. And fourth is early-life role models; in the late 20th century, it was about getting employment, but now it is about money, and money is a powerful motivator," revealed Kogo.

Scientific Dimension 

Interestingly, now we’re getting closer. The perspectives of those standing by these athletes daily give unparalleled insight. And so, with all that said, what does the final judge, science, say?

In the 1990s, Danish physiologist Bengt Saltin began bringing Kenyan runners into laboratories and comparing them with elite Scandinavians of equal training and performance. He expected to find bigger lungs, more slow-twitch muscle, or higher VO₂ max, which are the standard markers of endurance ability.

He found none of those. The Kenyans were no better on these measures, and yet they were faster, consistently, by margins that no amount of training could close. Something else was going on.

Three decades of research now point to a clear answer: the body itself.

East African runners, particularly from the Rift Valley region, tend to have longer, relatively lower legs, lighter and thinner calves, lower body fat in the limbs, and longer Achilles tendons. The lower leg, when it is light and long, swings like a more efficient pendulum, with every stride costing less oxygen. The Achilles acts like a stiffer spring, storing and returning more free energy with each foot strike.

And crucially, a 2025 study by well-known researcher Henrik Larsen found these features in untrained Kenyan adolescents who had never trained as athletes, when compared with Danish peers. That is the strongest evidence yet that something is present before the running shoes go on.

East Africans also appear to burn fuel more cleanly at race pace. They accumulate less lactate and ammonia, the chemical signals of fatigue, and they extract more energy from each breath of oxygen they take in.

That said, none of this means every athlete from Rift Valley is born to run a sub-2:30 marathon.

Variation within a population is almost always larger than variation between populations. So, while the Kalenjin of Kenya and Oromo of Ethiopia show unique body patterns at a group level, only some individuals carry the most favourable traits, and plenty of world-class endurance runners have come from outside the Rift Valley. Presence of an advantage in one place does not mean it is absent elsewhere. The science describes tendencies, not predestination.

The question, however, might be how these features came to occur naturally at a population level, and for this, various theories exist, including one of cattle rustling in some parts of Rift Valley.

All said and done, the current consensus is that Kenyan dominance is not a single-cause story.

Susan Kanyuga, Jonathan Tuzo, Brian Komen, Peter Kogo, and the researchers at Loughborough may emphasise different pieces, but they are all describing the same elephant. It is altitude, milk and miles to school. It is pain tolerance, role models, and the camp culture Brian Komen describes. It is also bodies that, after centuries of life in the highlands, appear to be unusually well-suited to the demands of distance running. Pull on any single thread, whether it be culture, environment, or biology, and the others come with it. And so yes, they were all right, to some extent.

Nurture talent 

The funny thing is, the relevant authorities might have barely scratched the surface in terms of full potential of talent within the country.

Kogo is optimistic about this, sharing that in Nandi County, community runs are now being held twelve times a year over school holidays, drawing children from age five right up to sixteen.

"We are still early," he says.

"With more structured strategies and more financial support, there is much more talent to come out of this country."

So, the message is perhaps to buckle up. The structures are still being built, and if replicated across the country, the next generation of five-year-olds running in those holiday community races may yet take the records into territory we cannot currently imagine. Until then, the best we can do is just enjoy the show. And, if you happen to be Kenyan, take a small moment of pride in it.

-The writer is a Sports PhD researcher exploring performance optimisation in footwear at Loughborough University, United Kingdom.