ITEN — On the eve of their departure for this week's Athletics World Championships in Beijing, Kenya's marathon runners were gathered for a goodbye luncheon organized by the local county governor. A prayer is offered. "Lord, be proud of our athletes."

The event takes place in the mountain hotel that hosted the seven champions during their training in the town of Iten, long the hub of Kenya's legendary long-distance running world. Electric cables hang from the ceiling of the dining room, which is still in the process of being painted. Outside is a red clay running track, with a few motorcycles and passing runners.

The athletes are asked to say a few words. They stand up, arms crossed, revealing with extreme timidity their long, strong legs, murmuring their names without a smile, looking lost. Mark Korir, the winner of April's Paris Marathon, sitting with his back against the wall, barely dares to stand up. Helah Kiprop, who won the 2014 Seoul Marathon, motionless on her chair, looks like she's facing trial — her magic feet, in simple white flip-flops, already seem to want to escape through the exit.

This should have been an occasion for smiles and good cheer. Instead the atmosphere is all gloom. We had already been warned that the team would not talk to the international press. Dennis Kimetto, the world's fastest marathon runner, isn't even here. The interview that had been planned was canceled at the last minute.

The problem — the subject dominating everyone's silent thoughts — is the specter of doping, which has haunted the team since early August, when the German television network ARD and the British weekly The Sunday Timesmade bombshell revelations involving athletes from a number of countries, including Kenya.

The two news outlets had access to 12,359 blood tests, administered between 2001 and 2012 by the International Association of Athletics Federations (IAAF). Out of a 5,000-athlete control group, 800 provided "abnormal" samples. Among them, 18 Kenyans.

Marathons, the main discipline for runners here in the Rift Valley of southwestern Kenya, is at heart of the case. A gray leather jacket on his shoulders, Wilson Kipsang, the team's leader and brains, winner of the London and New York Marathons, finally agrees to say a few words. Like others in Kenyan athletics, he is squarely on the defensive.

"The doping scandal doesn't affect us at all," he says. "We never talk about it. We have an excellent team, the best in years, and we will win the World Championships. The "revelations' are only rumors. Doping exists everywhere, not only in Kenya."

Running from poverty

At 5:45 a.m., it's still pitch dark in Iten, 350 kilometers from the capital, Nairobi. At the entrance of the village, the street-wide red and green sign that reads "Welcome to Iten, Home of Champions" is barely visible. Suddenly, a group of about 40 young athletes appears. The car headlights make their multicolored sneakers and tracksuits shine. After a bit of stretching, the marathon runners begin to circle the track, with large strides between the podocarpus shrubs and the cornfields. The roosters are still asleep.

Elijah, 16, is one of the pre-dawn runners. He is training for long-distance races, between 5,000 and 10,000 meters. Like so many of the athletes here, he comes from a very poor family in a neighboring village and was sent to Iten "to become a champion." He lives in the small Lillies neighborhood, between the Olympic village and the slum, where men and boys from the region gather in small sheet metal houses, train together, share advice and success.

"My family sends me 100 shillings (just under 1 euro) per month for supplies," the teenager explains. That isn't enough for Elijah to buy himself a second pair of sneakes. The ones he wears now are already covered in holes. "I train three times a day," he says. "The tracks are full of stones. It's not always easy."

Elijah says he doesn't take performance enhancing drugs. Nor, he insists categorically, has he seen anyone else take them. "Besides, it's bad for you and against the values of sport," he says. "To those who think about it, I say: train more."

And yet in the past three years, more than 35 Kenyan athletes, including Rita Jeptoo, the three-time winner of the Boston Marathon, have been knocked off the podium, crossed off by the IAAF or suspended by the Kenyan federation.

Far from prying eyes, on a road outside the village, in a car with closed, tinted windows, we meet Peter Kibet, an investigative journalist specialized in doping. A group of six runners passes by with small strides, sweat on their foreheads. "Out of the six, at least one or two dope," says Kibet. "I could even tell you which ones, just by the way they are running."

Kibet continues: "I've never believed that athletes could run a marathon in just two hours. For me, it's physically impossible. A world record used to hold for 10 years. But since 2007, it's broken every two years, almost every time by Kenyans, while the training conditions in Iten haven't changed since the 1980s."

Done deal

It's true that the region's running tracks have never really been modified, and are used just as much by cows and goats as by distance runners. What has changed is the increased availability of Erythropoietin (EPO), a hormone that spurs red blood cell production. "It's very common," says Kibet. "Between 30% and 40% of athletes here dope."

Demand for the product is high. "At least two runners came to see me every day to ask me for EPO," says Eunice, who worked in a public hospital in Eldoret, Kenya's fifth largest city. "They faked stomach or headaches and remained very vague, in order to be sent to the lab for examination, where they would find a willing listener …" In half an hour, for a 1,000 euros or more, a deal was made. And the race won.

In Iten, all roads lead to the Kamariny stadium. Every day, hundreds of runners come here for their interval training, alternating semi-sprints, small strides and deserved rest, between the sheep surrounding the worn blue podium.

On the grassy ground, in the middle of the arena, we come across a short man, his cheeks reddened by the sun, a woolly sweater and a baseball cap on his head. Born in 1949, Brother Colm O'Connell arrived in the Rift Valley almost 40 years ago. This Irish missionary who became coach, including for David Rudisha, the 800-meter Olympic champion at the 2012 games in London, has a decades-long relationship with Kenyan athletics. The nation's athletics system that dominated world long-distance running is now threatened to its very core by doping.

"It's terrible, but the slightest unusual performance is now seen as suspicious," says Bro Colm, as he's known. The coach's young athletes extend their strides. One minute for 400 meters. It's good. Too good?

"We can't control every single one of their moves," he says. "The truth is that we lack coaches here. That's the real problem! There aren't even five of us in Iten, all foreigners. We need more supervision. These young athletes are poorly educated. They come from very poor villages. They're very vulnerable."

Fall from grace

It's evening, and darkness has returned in Iten. The last runners head home, a few dozen kilometers more for their sneakers. This is when Ronald Kipchumba Rutto agreed to meet us. The athlete seems worried, glancing left and right as we are introduced.

A short time ago, Rutto was still one the great hopes of his generation. "From 2004 to 2009, I was among the world's greatest," he says. "In Frankfurt, I ran the marathon in 2 hours and 9 minutes. When you reach this stage, under 2 hours and 10 minutes, money starts flowing in, sponsors put on pressure, so does the federation."

After he reached the top, Rutto became afraid his level would drop. He chose to start doping. After a positive EPO control in 2012 after a marathon, he was suspended for two years. "I was convinced by a friend," he now admits. "I needed money for my family that stayed in the village. An average marathon brings in $10,000 to $12,000, not counting money from sponsors."

Rutto became an outcast. His coach left him, as did his manager and friends. "My wife left with my child, whom I haven't seen since. Nobody wants to employ me or lend me money," he says. The runner had to return to work in the fields. Any regrets? Rutto laughs. "I was conned. I didn't think I'd be checked. But I don't feel guilty. I had to feed my family."