New Zealand's Arthur Lydiard pioneered long-distance training.
The Kenyans have proved his running theories are correct by dominating the world middle- and long-distance scene over the last 30 years.
At the Beijing Olympics, in 2008, Kenya finished third behind the United States and Russia on the athletics medal table.
Its runners dominated the middle- and long-distance events, and won 14 medals, including six gold.
The key to the Lydiard method is establishing a big aerobic base.
A runner's speed and success comes from that.
The Kenyans achieve this from a young age by running to school.
But they do not think of this as training.
English author and Runner's World contributor Adharanand Finn took his family from Devon to the small town of Iten, in Kenya, to discover that country's running secrets.
The popular view is that living at altitude is the reason for the success of Kenyan and other African runners.
In his book Running with the Kenyans (Faber and Faber, 2012), Finn argues this view is too simplistic.
He has outlined more reasons why Kenyan runners have been so successful on the world scene.
One of the most important is that most Kenyan runners have a solid 10-year mileage base by the time they start becoming serious runners at the age of 16 or 17.
Kenyan children are active.
Everyday life gives them a good training base.
Finn believes Kenyan running success comes from the "inherent physical toughness" of their daily life.
"They come from poor rural families.
"They have yet to have a good runner from a city," he writes in the book.
"The life of the rural poor in Kenya is tough.
"From a young age they have to work hard, herding goats or digging in the fields, and they run or walk everywhere.
"It is the perfect groundwork for an endurance athlete."
The elite Kenyan runners grow up on the slopes of the Rift Valley, away from the technologies of the West.
"To build your aerobic house, to have enough of an endurance base to run long distances takes about 10 years," Finn says.
"By the time a Kenyan is 16, he has built this house."
Kenya was recognised as a top athletics nation when Kip Keino flashed on to the scene by winning gold medals at the 1968 and 1972 Olympic Games.
This started a running tradition in Kenya but it did not ignite the running boom that started in the mid-1980s.
In 1975, 23 marathons were run under 2hr 20min by British runners, 34 by Americans and none by Kenyans.
Thirty years later, in 2005, there were 12 sub-2hr 20min marathons run by British runners, 22 by Americans and 490 by Kenyans.
The boom started when athletics became professional and it was possible to earn a living from the sport.
"For a Kenyan runner, driven on by a will to change his life, the stakes are much higher," Finn writes.
"For someone who has spent years living at a subsistence level, even $US1000 can change everything.
"Virtually every village has its running star, someone who has packed a bag and gone off to win world titles or big road races abroad.
"They have returned rich by Kenyan standards, driving a big Land Cruiser, building a brick house, buying a cow and some land to plant maize.
"The great expansion of Kenyan running coincided with the rise in financial rewards.
"Once professionalism took off in the mid-1980s with prize money and appearance money, that was when Kenyan runners started to dominate."
There is poverty in other parts of the world where children also run barefoot to school.
"The difference is that in Kenya there is an established running culture, ready to take advantage of it."
The Kenyan diet also plays its part in developing world-class runners.
Finn said everyone in the Rift Valley grew up "eating a diet full of carbohydrates, with very little fat.
Beans, rice, ugali and green vegetables are the staples.
Occasionally the runners will eat meat or drink milk.
"It is very hard, in the town of Iten at least, to find cakes, ice cream, cheese, burgers or pizzas."
Ugali is the runners' favourite food.
It is maize flour and water boiled up to make a white sticky dough.
Finn lost 8kg after leaving England and weighed 69kg when he left Kenya.
"Some Kenyan runners were taken to Germany to study their physiology and they all put on 5kg in just two weeks."
Finn highlighted the big difference between the Kenyan athletes and those in England.
"In England when we are not running we go shopping, cook food or meet up with friends.
"In Kenya they just rest."
Most Kenyan children do not have shoes and they learn to run barefoot when they are young.
They use the same style when they wear running shoes.
"Kenyan children can feel the ground and learn to place their foot carefully when they run, so they don't hurt themselves.
"They learn to land gently, lightly,and glide over the earth, rather than pounding it.
"They land with their forefoot first."
Kenyans do not like running on concrete and run only on grass or dirt roads.
The runners are mentally tough because they are used to hardship in their daily lives, so that when it comes to the end of a race they are better equipped to endure the pain.
Kenyan runners
Keys to success
Tough active childhoods.
Barefoot running.
Living at altitude.
Simple approach to training.
Diet - carbohydrate rich, low in fatStrong endurance base.
Mental toughness.
Running off roads.
Hunger to succeed.
Financial incentives.
All-pervading running culture.
Time spent resting.
Source: Running With The Kenyans, by Adharanand Finn
