LONDON • This weekend, aided by a host of technological and environmental advances, three carefully-selected elite African athletes will attempt to run the first sub-two-hour marathon.
The "Breaking2" project is the latest enterprise of American sportswear giant Nike and has split opinion in the world of athletics, not to mention physiology.
In one camp are the "purists", who claim that the host of benefits being bestowed on the runners - including revolutionary shoes, a pack of interchangeable pacemakers and a non-traditional course - means that the attempt is a marketing gimmick.
In some ways, this is possibly the worst time to start shouting about fast marathon times, with Kenya's Rio Olympic and London marathon women's champion Jemima Sumgong's recent positive doping test landing a body blow to the event.
Nike, and others, however, insist projects like Breaking2 show that a combination of talent, training and technology can produce astounding results without the need for chemical assistance.
Many people are intrigued to see just how much difference such a collection of "marginal gains" can make and suggest that, at a time when athletics is reeling from relentless bad news, such a quantum leap in human endurance, arguably the greatest in the sport's history, is something to be welcomed and celebrated.
Kenyan Dennis Kimetto set the current record of 2hrs 2min 57sec in Berlin in 2014, which is about four minutes faster than the world record was in 1988.
Kimetto's time works out to 4min 41sec per 1.609km; a sub-two-hour run for the 26.219-mile (42.195km) marathon would require less than 4min 35sec per mile - an improvement of about seven seconds per mile, or around 2.5 per cent.
On the face of it, that appears an impossible leap.
Three exercise physiology experts predict a world-best time when Kenyan Olympic champion Eliud Kipchoge, Ethiopia's Lelisa Desisa and Eritrea's Zersenay Tadese take to the Monza motor racing track, but say it might not produce a sub-two-hour marathon.
"This is physiologically possible, the athletes attempting it, the pacing scheme, the shoes and the course should all make a difference," Michael Joyner, an expert in human performance at the Mayo Clinic, said.
"However, a 2.5 per cent jump in a distance running record is very big by historical standards and the weather is the wild card."
Joyner thinks there is a roughly 50 per cent chance one of the runners will run faster than 2:01:30.
"That time would represent a great accomplishment and really reset the whole conversation," he said.
Another expert, Mike Hahn, predicts a winning time of roughly 2:00:30.
The director of the Bowerman Sports Science Clinic at the University of Oregon said: "It is physiologically possible (for someone to break two hours). It's a little harder to pin down exactly when it will happen."
Evan Day, a PhD student at the University of Oregon and an expert on running economy and foot mechanics, is going out on a limb in predicting the two-hour barrier will fall, probably to Kipchoge, who has sizzling track speed to back up his endurance.
"The world record is a definite, it's just a matter of by how much," Day said, before making his prediction for the weekend - 1:59:59.