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Yiannis Kouros suggests Kilian Jornet is shoe doping for 24-hour world record attempt

Hours before Jornet began his 24-hour world record attempt, Yiannis Kouros ranted on Facebook about cheater shoes

Kilian Jornet

Kilian Jornet is six hours into a 24-hour track world record attempt. The runner is attempting to break ultrarunning legend Yiannis Kouros’s record of 303.506 kilometres, which he set in 1997. The Phantasm24, as it’s called, is underway at a track in Måndalen, Norway, not far from Jornet’s home. In a year of limited racing and few sporting events, Jornet’s run has received huge attention. It helps that his talents span mountaineering, ultrarunning, trail running, road and track racing – so he’s got a vast array of fans from all sides of the sport. However, despite his many supporters, one prominent naysayer has emerged – the current world record holder, Kouros.

RELATED: How to watch Kilian Jornet’s 24-hour world record attempt

Yesterday Kouros shared a long post on Facebook detailing his displeasure with what we must infer is Jornet’s WR attempt, citing shoe doping as his main concern. His post follows.

Kilian Jornet
Photo: Pascal Tournaire/UTMB

Shoe doping is a term that has emerged over the past few years, beginning with the Nike Vaporfly and reaching its height in 2019 with the unofficial release of the Alphafly. Shoe doping refers to the mechanical advantage certain runners were believed to benefit from by running in prototype high-stack, carbon-plated shoes that weren’t available to the general public. World Athletics has since put a cap of 40mm on midsole foam stack height for road racing, and the maximum for track events is 25 mm. Recently, the IAU adopted similar rules to WA’s, but with a slight twist. Ultrarunners may wear shoes with a stack height of up to 40 mm for all events on all surfaces. Also, only shoes that can be purchased by the general public may be worn in competition. This means runners may not race in shoe prototypes supplied by their sponsor. 

Yiannis Kouros (#108), Sandy Barwick (#114), Emile Laharrague (#109) at the Sri Chinmoy 1,000 Mile IAU World Championships. Photo: courtesy of Sri Chinmoy Archives

The post

“What a pity! to hear that there are athletes who considered as well known, but they seek short-cut ways and they try to innovate unfair methods in order to cheat! An easy way by short-cuts is always the unfair and the anti athletic way that equals to cheating……!!!!!!

Regulations about official running are set long before us!

I appreciate performances done officially and under regulations that are equal to all competitors!!
And the companies that are behind these anti athletic notions and irregularities with which are encouraging and pushing athletes to cheat are also guilty!”

Canada’s most prolific ultrarunner and the holder of numerous Canadian ultrarunning records, Trishul Cherns is watching Jornet’s attempt with great interest, and he prefers to give Kouros (widely regarded as the greatest ultrarunner in history) the benefit of the doubt. Cherns says, “Perhaps Yiannis is unaware that Kilian’s shoes are legitimate. I am personally cheering on Kilian’s attempt at 24 hours. This record is at the top of Mount Olympus. Let’s see if Kilian can scale to the summit and where Kouros has stood.”

RELATED: IAU adopts World Athletics shoe rules for ultramarathons

Kilian’s attempt

The event has been named Phantasm24, referring to the new shoe that Jornet is wearing: the S/LAB Phantasm, a road-racing flat from Salomon. The shoe does not have a carbon plate and its stack height falls well under the 40mm limit, at 20mm. While the shoe is currently sold out online, it remains technically available for purchase (you’ll just have to wait a few days).

Kouros’s displeasure is one that’s felt by many purists who feel that the sport has become a technology arms race as opposed to an equal-opportunity endurance sport. Unfortunately, the purists are going to have to get accustomed to the new normal, as running shoe technology isn’t going anywhere. And ultimately, like it or not, a guy like Jornet and shoes like Nike’s are bringing new fans to the sport.

RELATED: Runners push back against new World Athletics shoe rules


At 7 hours and 22 minutes, Jornet has run 99.6K, averaging 4:37 kilometers. To break the record, he needs to average 4:45 per K, so he’s currently ahead of pace. The live feed can be found here

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