3 athletes who are attempting the sub 2-hour marathon in 2017

Kipchoge, along with the other runners, did treadmill tests at Nike headquarters earlier this month. The mask he’s wearing allows researchers to measure how much oxygen and carbon dioxide he’s inhaling and exhaling, enabling them to calculate his maximal aerobic capacity (VO2 max) and how much energy he burns at different running paces. Photography by Nike/Clayton Cotterell

Nike has announced the launch of its ambitious Breaking2 project - a plan to break one of running’s most formidable barriers - the two-hour marathon - in 2017.

In the end, of course, none of the science matters without athletes capable of executing the plan. Here, in no particular order, is a primer on the contenders:

​Eliud Kipchoge

Country: Kenya
Age: 32
Height: 5’6”
Weight: 115 pounds
Best times: 12:46 (5000 metres), 26:49 (10,000 metres), 59:25 (half marathon), 2:03:05 (marathon)

Quite simply, Kipchoge is the best marathoner in the world right now - the Olympic gold medallist from Rio, 13 years after he burst onto the scene with a surprise World Championship win in the 5,000m as an 18-year-old. He has shown unprecedented consistency in the marathon - with seven victories in his eight career marathons - but remains humble, cleaning toilets and chopping vegetables [16] in his Kenyan training camp despite his celebrity status.

Three weeks ago, Kipchoge won a half marathon in Delhi in 59:44 - an impressive time, to be sure. But can he go twice the distance at nearly the same pace? He smiled when we asked him. He’s not in peak condition right now, he explained - but still, he admitted, ‘it’s really intimidating, mentally.’ If there’s one question about Kipchoge, it’s this: can someone who’s so clearly at the top of his game, and who has been at the top for over a decade, find room to get even better?

Lelisa Desisa

Country: Ethiopia
Age: 26
Height: 5’9”
Weight: 125 pounds
Best times: 27:11 (10,000 metres), 59:30 (half marathon), 2:04:45 (marathon)

When Desisa was a kid, his school was a 50- to 60-minute walk away from his rural home - not far enough for the aspiring runner, so he would give his books to his friends and run a longer way home. These days, he is best known in the United States as the man who won the Boston Marathon in 2013, only to see his triumph turn to tragedy when bombs exploded two hours after he crossed the finish line. He later returned his first-place medal to the city of Boston in a public ceremony, and in 2015 he won again under happier circumstances.

Among the three runners, Desisa is the young gun and potentially the most untapped. His marathon best of 2:04:45 was set in his very first marathon, at just 23, and he feels that with the Nike support team he can improve dramatically. ‘We see each other as brothers, as friends,’ he says of his new teammates. ‘But when it comes to running, we’re competitors.’ In other words, he wants to be the one to break the barrier - and he believes he can: ‘Yes, God willing, I’ll do it.’

Zersenay Tadese

Country: Eritrea
Age: 34
Height: 5’3”
Weight: 119 pounds
Best times: 12:59 (5,000 metres), 26:37 (10,000 metres), 58:23 (half marathon), 2:10:41 (marathon)

Tadese is both the most obvious and most surprising pick of the three. Let’s start with the pros: he’s the world record holder at the half marathon, and four-time world champion at that distance. He’s also an Olympic medallist on the track and a World Cross-Country champion. More intriguingly, physiological testing published in the British Journal of Sports Medicine in 2007 pegged Tadese as having ‘one of the lowest (if not the lowest) ever published values’ for running economy, a measure of efficiency analogous to fuel economy in a car. Lower is better in running economy, meaning Tadese is one of the most fuel-efficient runners ever seen - a very useful trait for a marathoner.

The puzzle, then, is why Tadese’s attempts at the marathon thus far have been so disappointing. His best of 2:10:41 is far from his presumed potential. Moreover, most of his best performances came prior to 2012; his eighth-place finish in the 10,000 metres in Rio marked a return from relative obscurity, but was still far from his best. Based on their assessments, the Nike team clearly believes that Tadese has what it takes - and that they can help him finally unlock his considerable marathon potential.