(CNN)Eliud Kipchoge has likened his upcoming attempt to break the two-hour marathon barrier to Neil Armstrong’s historic moon landing in 1969, but one leading sports scientist says the conditions are “contrived” and likens it more to breaking the high jump record on Mars.
The 34-year-old Kipchoge, who ran the fastest ever official marathon last year in Berlin in a time of 2:01:39, will try to dip under two hours in Vienna in October, aided by a group of pacesetters and running behind a lead car that will serve as a wind resistor.However, Professor Ross Tucker, the respected South African who served as an expert witness in Caster Semenya’s hearing at the Court of Arbitration of Sports (CAS) earlier this year, is sceptical about the variables involved in the venture, dubbed the INEOS 1:59 Challenge.”Getting man to the moon involved overcoming gravity. What Kipchoge is doing is taking gravity out of the equation,” Tucker told CNN Sport. “It would be the same as breaking the high jump record [set in 1993 by Cuba’s Javier Sotomayor at a height of 2.45m] on Mars where there is less gravity.”READ: Caster Semenya blocked from competing at World ChampionshipsEliud Kipchoge won the London Marathon this year.Read MoreRemoving gravityThe rationale behind Tucker’s claim helps explain why the International Association of Athletics Federations (IAAF), the governing body for the sport of athletics, will not recognise Kipchoge’s time as part of its official record. “People within the sport who understand the constraints of what normally regulates or limits performance would appreciate that this isn’t comparable [with the moon landing],” Tucker said. “The variables are too contrived for this to be regarded as a pure human accomplishment.”However, INEOS spokesperson Tom Crotty said in a statement: “The sub-two-hour marathon remains one of the last barriers in sport,” and Kipchoge’s achievement would represent a “next step to make history, leave a legacy, and show that no human is limited.”Kipchoge, who missed breaking the two-hour mark by just 25 seconds in Monza in 2017, added: “It is not about a world record. It is about passing the message of inspiration to the whole human family. I am already the record holder for marathon but I need to do this for the human family.”READ: Kenyan runner comes close, but two-hour marathon barrier remains unbrokenEliud Kipchoge won the 2019 London Marathon in 2 hours 2 minutes 37 seconds.A technological boostTucker is concerned that modern high-performance running shoes are so efficient they take away from the human achievement.Last year, The New York Times released a comprehensive report detailing the significant improvements Nike’s Zoom Vaporfly 4% shoes — worn by Kipchoge and on public sale at $250 — afford men and women of all levels and ages. This primarily comes in the form of the assisted spring the shoes provide, propelling the runner forward while preserving energy.According to Tucker, a runner expelling four percent less oxygen for the same energy output is able to improve on his or her performance by 2.5 percent at the elite level. Over the course of a marathon – 26.2 miles (42.2km) – this could translate to as much as two minutes. While the Nike shoe is perfectly legal, it throws up a similar situation to the swimsuit that took the 2008 Olympics by storm. In Beijing, 94 percent of all swimming races were won by athletes wearing Speedo’s LZR Racer swimsuits, according to Time Magazine. Michael Phelps said he “felt like a rocket” in the swimsuit before claiming an unprecedented eight gold medals in Beijing. At the European Short Course Championships in Croatia later that year, 17 records fell to swimmers wearing the LZR which prompted the International Swimming Federation (FINA) to change its rules regarding the length and material of sanctioned swimsuits.”We’re talking about performance integrity,” Tucker argues. “Is Kipchoge an outlier of immense athletic potential? Or is he a simply a very good runner who is benefiting from the immense improvements that his shoes provide? Perhaps both. “But the point is we don’t know with absolute certainty. Running, especially marathon running, is supposed to be the purest thing humans put themselves through. It’s just about feet, legs, lungs, heart and brain. These shoes create the same problems that doping throws up.”Eliud Kipchoge (right) and Mo Farah (left) show off their running shoes ahead of this year’s London marathon. ‘Reassess what is achievable’Though Tucker remains unconvinced by the lasting legacy of the INEOS 1:59 from a pure athletic perspective, he believes it could raise the profile of the sport and shift expectations regarding a legitimate sub-two-hour marathon.Visit CNN.com/sport for more news, features, and videos“It won’t matter in people’s minds that the bar was reset in a different ecosystem,” Tucker said. “The fact that a human body will cross that line in under two hours will stick in the minds of people who have struggled with barriers. “Perhaps people who run Parkruns will now reassess what is achievable and it might inspire them to push themselves further. But no one within the sport is going to be thinking of this when the next big money marathon rolls around.”Whether Kipchoge’s attempt is as revolutionary as a moon landing or more akin to high jumping on Mars is a matter of opinion. Either way, a sub-two-hour marathon would constitute a new frontier in human physiology.