World Athletics has tightened regulations around the high-tech running shoes which have contributed to broken marathon world records while causing a wave of complaints from other runners.
In a statement, the governing body said there would be “an indefinite moratorium” on shoes that do not meet the new requirements — which includes the shoe that Eliud Kipchoge ran his sub-two-hour marathon in.
However, World Athletics has decided not to implement a complete ban on the Nike Vaporfly shoes, which features a carbon fibre plate and a thick foam midsole, but has ruled out the use of modified versions of the shoe and restricted the thickness of the sole to 40mm.
Any shoe that “may not be compliant with the rules of the spirit of the rules,” may be submitted for testing.
In fact, competition referees have been given the power to request that an athlete hands over their shoes for testing immediately following a race that arouses suspicion.
The rules have been designed to provide some certainty heading into the Tokyo Olympics, starting in July.
Here’s what that means for athletes in the lead up to the biggest sporting event on the calendar.
Why has World Athletics stepped in?
World Athletics formed a panel to investigate the shoes after formal complaints by athletes and has been considering evidence from a group of experts.
The head of the governing body Sebastian Coe said that the new rules preserve the integrity of the sport.
“It is not our job to regulate the entire sports shoe market but it is our duty to preserve the integrity of elite competition by ensuring that the shoes worn by elite athletes in competition do not offer any unfair assistance or advantage,” he said in a statement.
Athletes have complained that the shoes are tantamount to “technological doping” and Australian marathon great Robert de Castella called for the “ludicrous” shoes to be banned as they go against the “spirit” of athletics.
The Nike shoes have made a significant mark on the marathon world in the last few years.
Kenyan runners Eliud Kipchoge (two hours, one minute, 39 seconds) and Brigid Kosgei (2:14:04) have set new world records wearing versions of the shoe.
Tweet by @seanwhipp: “A better image of Adidas athlete Herpassa Negasa (ETH) and his interesting shoe choice for the Dubai Marathon – dyed Nike VaporFly 4%’s the flavour of the day (source: LetsRun used ‘reed’). Can’t imagine Adidas would be over the moon re: shoe choice whilst running 2:03:40.”
The four fastest official men’s marathon times in history, and seven of the top 10, have been set in the last 18 months by Nike sponsored athletes.
Kipchoge also wore a modified version of the shoe for his historic sub-two-hour marathon in Vienna in October, although it did not count as an official record.
Regulations state that running shoes “must be reasonably available to all in the spirit of universality of athletics and must not be constructed so as to give athletes any unfair advantage or assistance”.
Some athletes sponsored by other companies appear to have gone to great lengths to get hold of the shoes, which cost $320 and have a lifespan of about 320 kilometres.
Ethiopian Derara Hurisa won the Mumbai marathon earlier this month, setting a new course record, in a pair of borrowed Vaporfly shoes after claiming his other shoes were “lost” on the flight from Addis Ababa.
His compatriot Herpassa Negasa finished second in the 2019 Dubai marathon, at the time the 10th fastest run in history, in a pair of the shoes which appeared to have been dyed red.
How does the technology work?
Experts say the advantage gained by the shoes comes down to the design, which includes a thick foam midsole and a carbon fibre plate.
Other manufacturers have also released, or are developing, their own carbon-insoled shoe.
Shoes that do not meet the following requirements are now banned:
- The sole must be no thicker than 40mm
- The shoe must not contain more than one rigid embedded plate or blade (of any material) that runs either the full length or only part of the length of the shoe. The plate may be in more than one part but those parts must be located sequentially in one plane (not stacked or in parallel) and must not overlap
- For a shoe with spikes, an additional plate (to the plate mentioned above) or other mechanism is permitted, but only for the purpose of attaching the spikes to the sole, and the sole must be no thicker than 30mm
- From April 30, shoes must have been available for purchase on the open market for four months before they can be used in competition
Sports podiatrist Gary Johnstone told ABC News Breakfast the shoes were designed to absorb shock and propel the body forward by acting like a spring.
“Essentially, there’s nothing majorly different. The stand-out feature is the type of foam that the midsole is made of and the stack height, the overall height through the heel,” he said.
“With this particular foam, it is extremely responsive so it releases a lot of energy once it’s been under load, so it springs back into shape.
“The fact that it’s kept so light also improves running efficiency. Prior to that technology, it’s been all about trying to strip that material away from the shoe but then that impacts the amount of energy released.”
Tom Allen, from the Institute of Sport at Manchester Municipal University, told the BBC the carbon fibre plate also made a difference.
“That adds stiffness to the length of the shoe and allows the athlete to have greater leverage. It also stiffens the front of the shoe and allows them to run more efficiently,” Dr Allen said.
Do the shoes really make that much of a difference?
Aside from results and the effort athletes have made to get their hands on the shoes, studies have shown they do contribute to improved performance.
Journal Sports Medicine published a 2017 University of Colorado study of 18 high-calibre athletes which showed the shoes reduced the energetic cost of running by 4 per cent compared to two other types of marathon racing shoes.
In December, the New York Times published an analysis of more than 1 million marathon and half marathon amateur times since 2014, of runners of all levels, finding that switching to the shoes gave a runner a “significant advantage over a competitor [of the same ability] not wearing them”.
Strava, the global social network for athletes, said in its 2019 review that the median marathon finish time for runners in the Vaporfly model Next% was 8.7 per cent faster than runners wearing the next fastest shoe, the Adidas Boston.
The question over whether they are fair is a separate matter.
“Nike’s point of view on that is that it doesn’t actually increase the amount of energy from the shoe, it just maximises the energy return. In saying that, it has shown to be 30 to 40 per cent increase in that energy return,” Mr Johnstone said.
Swimming faced a similar technology problem in 2009 after 100 world records were broken in the space of 18 months. (Jenny Evans: AAP)
Bruce Dyer, a sports technologist at Bournemouth University, said the shoes’ benefits are “the equivalent of bringing a gun to a knife fight” but rejected that they were unfair.
“If they produced more than 100 per cent energy return, then I’d agree they are enhancing. But from the studies we’ve seen, these shoes don’t appear to be doing that, so I’d say it’s purely a question of efficiency,” he told Reuters.
The case has drawn parallels with the controversy faced by swimming during the “super-suit” era a decade ago.
Swimming’s world governing body, FINA, moved in 2009 to ban “fast suits” that provided extra buoyancy and reduced drag in the water.
FINA launched a review of technology in swimming suits after 100 world records were broken in the space of 18 months.
Some experts have highlighted in technological advancements in other sports, including skinsuits in skiing, hinged blades in speed skating and aero bars and disc wheels in cycling, have become standard equipment.
What happens now?
The World Athletics ruling will require all manufacturers to submit any existing prototypes for approval before use in major competitions, which will put a halt to any technological advancements until after the games.
The new rules will restrict the thickness of the midsole and the governing body plans to conduct a longer-term biometric study of the technology.
All records set by athletes wearing the shoes will continue to stand and the ruling will not affect the use of the shoes by recreational runners.
Coe did not rule out further changes to the rules if evidence suggests an unfair assistance is provided to athletes who wear the shoes.
“I believe these new rules strike the right balance by offering certainty to athletes and manufacturers as they prepare for the Tokyo 2020 Olympic Games while addressing the concerns that have been raised about shoe technology,” Coe said.
“If further evidence becomes available that indicates we need to tighten up these rules, we reserve the right to do that to protect our sport.”
Yannis Pitsiladis, a professor of sport and exercise science at Britain’s Brighton University, said if World Athletics had done nothing to halt advances in shoe design, “the consequence is going to be a race between the manufacturers rather than a race between the athletes”.
Before the changes were announced, Nike has released a statement saying it respects “the spirit of the rules and we do not create any running shoes that return more energy than the runner expends”.