The unstoppable rise of the 'super shoe' - and how it caused 'mayhem' in athletics
By the start of 2020, it was evident something was afoot. By World Athletics president Seb Coe’s admission, the governing body had “been chasing the horse around the paddock” in failing to react quickly enough to developments in road-running shoes and it was too late.
Nike’s technological innovations had changed the marathon landscape forever and no elite runner would ever take the start line again without some combination of carbon fibre and hyper-responsive foam under the soles of their feet. The horse had bolted.
Now the governing body had a secondary problem of attempting to shut the door on the same happening on the track.
Little more than a year on, its failure to do so has been brought into sharp focus and threatened to overshadow much of what will take place at the Olympics this summer. Courtesy of previously unheralded athletes making headlines with astounding performances during the indoor season, fissures that had been bubbling under the surface have developed into full-blown divisions as debate blights the sport and world records become sitting ducks.
Behind it lies a secretive world of non-disclosure agreements, cutting-edge technology and warring shoe companies, battling to help runners achieve feats many thought impossible. Many people, including some within the footwear industry, believe it should never have come to this.
Until January 2020, regulations on sole thickness had only ever existed in the high jump and long jump, with most track spikes so thin and lightweight that further limitations were not necessary.
But with shoe companies seeing the radical impact of marrying carbon-fibre plates with super-springy foam, prototypes for middle- and long-distance track spikes had emerged a few months earlier at the 2019 World Championships that suggested all that was about to change and limitations were quickly needed.
Where track spikes had rarely exceeded 15 millimetres in thickness in the past, World Athletics introduced a blanket 30mm sole thickness rule, later amended to 25mm for all track events beyond 400 metres. The reason for not going thinner was the existence of one particular thick-soled Nike spike rarely worn outside the American collegiate system.
“That was what created everything you see now,” one leading shoe company executive told Telegraph Sport. “It means you have all this room for plates and bounceability.
“The parameters are out of control. They should never have been what they are, but now we have them we are going to work with them.
“We’re going to have a period of two or three years where you have phenomenal athletes - let’s not belittle them - that are given a product that is definitely going to make them run faster. There will be faster times and records falling. In the short term it’s going to be mayhem.”
Barely an athletics competition has gone by this year without proof. Fresh from new women’s 5,000m, and men’s 5,000m and 10,000m world records during last year’s brief outdoor season, the past month has seen times continue to tumble in middle and long-distance events.
One men’s 3,000m race saw a 23-year-old world record missed by just 0.08 seconds as the first four Nike-sponsored finishers all moved into the top eight of the all-time world rankings. Nike-sponsored British athlete Elliot Giles, who has never reached a world final, smashed Coe’s national 800m record by more than a second with the second-fastest indoor time in history. And Nike-sponsored Marc Scott took 46 seconds off his 10,000m personal best to move second behind only Mo Farah on the all-time British rankings.
For many people - and no one more than the athletes themselves - the astonishing performances are reflective of hard work in training, the rare benefit of time during global Covid lockdowns, and peaking at the start of an Olympic year. But all have revolutionary shoes as a common factor.
The fast times of the past are destined to be consigned to history. As Geoff Burns, a biomechanics expert at the University of Michigan, says: “It’s like there are these gems that through all of our history we thought were super rare but now we’ve found a deposit of them that makes them a little bit less valuable.
“This year will be the equivalent of the move from cinder to all-weather tracks. It’s a generational shift.”
'The Magic' that changed running forever
Olympian and scientist Shalaya Kipp knew she was witnessing something that would change the marathon picture forever the moment she began “top-secret” testing of the latest Nike prototype road-running shoes. It was early 2016 and the first edition of what would become the Nike Vaporfly 4% was being put through its paces at the University of Colorado. Kipp, along with everyone else in the laboratory, was made to sign a non-disclosure agreement, preventing loose tongues causing details of the secret shoe to emerge.
“We started referring to the prototype as ‘The Magic’ in the lab because it was crazy,” says Kipp. “It improved the running economy of every single participant we put in these shoes. It didn’t matter if they hated the shoe or not. The smallest change we saw was two per cent and the biggest six per cent.”
There were two key components that marked the shoe out for such controversial greatness: a carbon-fibre plate and a new super-responsive foam. While the former was nothing new in isolation - carbon-fibre plates had been used in road-running shoes for well over a decade - it was the interaction with the new Pebax foam (which Nike called ZoomX) that changed everything.
“For a long time we had EVA (ethylene-vinyl acetate) foams and they were pretty bad,” explains Wouter Hoogkamer, assistant biomechanics professor at the University of Massachusetts.
“They were either soft and so you lost all the energy, or they had to be made really firm so you didn’t lose it. The result was minimal thicknesses for road shoes and track spikes.
“Adidas came along with Boost foam around 2013, which allowed a softer foam that gave more energy return. Now with the Pebax foam you have even more of that.”
A few months after the laboratory testing, the men’s Olympic marathon produced a Nike podium clean sweep through Kenya’s Eliud Kipchoge, Feyisa Lilesa of Ethiopia and American Galen Rupp. Disguised to look like the rest of the existing Nike footwear range, all three men were in fact secretly wearing the Vaporfly 4% prototype. “We were watching and knew exactly what was going on,” says Kipp.
What happened next is well-known. Almost every podium at every major marathon between 2017 and 2019 was filled by Nike-sponsored athletes in Vaporfly 4% and Next% shoes, with some athletes affiliated to other companies attempting to paint over the Nike branding after jumping ship to use their rival’s shoes.
Kipchoge would first smash the world record in 2018, before donning the latest iteration of the shoe - the Alphafly - to become the first man to run a marathon in less than two hours, albeit under highly-controlled conditions. Nike athlete Brigid Kosgei also obliterated Paula Radcliffe’s longstanding women’s marathon world record. Athletes running in rival shoes simply stood no chance. “It was guns versus knives,” says Burns.
Asked for their reaction to such inequality, Nike make no apologies for their ability to produce better shoes than their rivals. “Plates, foam and air are not new ingredients in running shoes or spikes, we’re just smarter about how we engineer and assemble them,” a spokesperson told Telegraph Sport.
Four years on, the situation is rather different, with other shoe companies catching up. Three of the four winners at last December’s Valencia Marathon and Half-Marathon wore the Adizero Adios Pro, which uses carbon-infused rods laid out to mimic the skeleton under the forefoot, and a carbon-fibre plate in the heel. One of the athletes, Kibiwott Kandie, broke the half-marathon world record.
After years of a mismatch between Nike road-running shoes and the rest, New Balance, Reebok, Saucony, On, Brooks, Hoka and Asics have now all released their own ‘super shoes’. The playing field is distorted from history, but it once again vaguely resembles something level among current athletes.
Laying down the ground rules
“There really hasn’t been a ton of innovation in track products for a long time,” says Danny Orr, New Balance general manager for running technology. “It’s always been a little bit around, ‘can it weigh as little as possible’ and, ‘can it have as much traction as possible’.
“For as long as I’ve been doing this, that’s all that has come the way of track athletes. So it does feel for the first time in 20 years there’s innovation in this space, which is exciting.”
While the outside world was watching performances on the road in wide-eyed amazement, shoe companies had realised the technological advances could now be used to conquer the second frontier of track athletics.
Prototypes, primarily from Nike, using the same technology began appearing with semi-regularity after Rupp is believed to have worn a pair in finishing fifth at the 2016 Rio Olympics.
By the 2019 World Championships, the finished product was almost complete with a number of Nike athletes - including gold medal winners Sifan Hassan and Donavan Brazier - producing outstanding performances in prototype shoes that would later turn into the Air Zoom Victory, with its carbon-fibre plate and air pod, and ZoomX Dragonfly, which features a rigid Pebax plate.
World Athletics had a decision to make. Track competition was on the brink of following road running, which had been blighted by accusations of technological doping. The question was whether the sport should follow the lead of swimming, which banned Speedo’s shark-inspired suits that saw world records tumble in 2008, or the likes of cycling, which encourages innovations in bikes, suits and helmets.
An added factor for the governing body was balancing what many perceived as the integrity of pure competition against the requirements of the shoe companies that provide athletics its main source of income.
“There is a built-in dynamic, where shoe companies mercifully are still investing a lot of money into the research and development of shoes,” said Coe, who relinquished a long-term Nike ambassadorial role in 2015. “I’m pleased they are doing that.”
Under pressure from Nike, World Athletics opted for a 20mm sole thickness limit on events up to 400m and 25mm for longer distances.
“They didn’t need to go to that extreme, but Nike argued there was already a shoe of that thickness in existence,” said one leading sports brand executive. “That was not a shoe that anyone wore in elite competition, but Nike said it had been worn at college level in America, so that was the basis for the rules we now have.”
Another shoe company executive said: “Brands are always going to innovate. Half the blame is laid at the feet of our international governing body who have not set the best guidelines for the last couple of years on shoe tech.
“We knew back in 2016/17 that this was coming through so they could have set ground rules right from the start. It was only 2020 that this started getting put in place and it’s still a moving feast.”
Having taken charge of athletics at a time when it was riddled with corruption and doping scandals, there remains a sense that Coe and his staff were simply unable to prioritise the shoe issue until it was too late.
A World Athletics spokesperson said: “Perhaps we should have responded quicker by bringing the shoe companies together, as we did in late 2019, but we would have followed the same process and set the same principles we are working to now.
“Our role as the regulator of our sport includes embracing innovation that helps athletes train and perform to their talented best whilst balancing that with fair play and reasonable access to new technology.
“Against a backdrop of light touch regulation in the past it was always going to take time for a critical mass of the race results to work through to a point where World Athletics felt it was time to intervene in a more proactive manner.”
On the 25mm limit, they added: “The maximum track shoe height was 25mm for a shoe that had been widely used for many years and was still being used across the athlete college system in the USA.”
How much improvement do the spikes provide?
For those who have benefited from Nike’s spikes, it is galling to hear suggestions that the footwear is responsible for their achievements. Giles described such statements as an “insult”, while Scott said sceptics should get off their “high horse” after his huge 10,000m personal best.
Others have been more forthcoming. Adidas-sponsored Jamie Webb, who also went under Coe’s old British record wearing ‘old technology’ spikes when finishing second behind Giles this month, said the evidence shows “we are entering a new era”.
New Zealand’s double Olympic 1,500m medalist Nick Willis, who no longer has a footwear contract, last month revealed he ran a 1,200m time trial two seconds quicker than he expected when trying out New Balance’s carbon-fibre Fuelcell MDx spikes. “I’m a believer in the new spike tech,” he said. “Far different to anything I have run in for my 20 years racing the mile.”
To date, only New Balance and Nike have provided athletes with ‘super spikes’ in competition over the past 12 months, with Joshua Cheptegei and Letesenbet Gidey smashing world records in the Nike ZoomX Dragonfly last summer. But any sense of inequality looks likely to be quashed by this summer, with Adidas, Brooks and Puma among shoe manufacturers due to bring out new ranges for the outdoor season featuring the carbon-fibre and super-responsive foam combination.
While various numerical estimates have been thrown around, the question remains over exactly how much improvement the shoes provide, especially given the surprising identity of some of the athletes producing such remarkable times this winter: Giles has never made a global final, while two unheralded US college students catapulted themselves to seventh and eighth on the all-time indoor mile list. Asked if there was any sense of percentage improvements, Nike simply said: “We are pleased with the results we have seen to date.”
Indeed, it is difficult to put a precise figure on it. So too with the often-compared move from cinder to all-weather tracks in the 1960s. Biomechanists believe that change provided around a 1.5 per cent advantage, but such was the effect of weather conditions on the cinder that there is no definitive number.
Of the spikes, Hoogkamer explains: “For marathon running, we can deduce that if you run a marathon at a certain pace you can do trials in six different shoes in the lab setting. But running 800m race pace is hard enough once, so you can’t do the same trial comparisons.
“The other thing is the marathon relies on aerobic capacity, which we can measure through oxygen uptake. For these middle-distances you get a huge amount of anaerobic contributions, which we still don’t know how to quantify. So measuring running economy at middle-distance race pace misses out all the anaerobic contributions. There’s no lab measure.”
Orr concurs it is “harder to put your finger on” due to the difficulty in measuring, but says the New Balance spikes produce “some of the most consistent data we’ve seen”.
All signs suggest what we have seen is just the start. Burns says the difference produced by this new shoe technology will likely prove more noticeable on the track than it has been on the road, forcing us to recalibrate how we perceive certain times.
“For starters, you race a lot more so the data set is larger,” he said. “And the conditions are hyper-controlled. On the roads you have lots of external factors to deal with and people tend to race only twice a year.
“In running we have associations with certain times - we have intrinsic connections to clocked performances. We’re basically seeing the distribution of those performances shift.
“What that means is the performances we associate with being rare and exciting are going to be a little less rare. Very quickly we are going to come habituated to those times becoming a bit less special.”
Records handed out like confetti
A second horse has bolted. World Athletics is currently looking into creating a formula that measures energy return, to potentially impose limitations through that route - rather than specific physical constraints - in the future. How to implement such regulations is tricky though, and such is the time-lag in shoe production that any radical rule changes would likely take years to put in place.
The spikes are here to stay and will dominate middle- and long-distance races at the Tokyo Olympics, although with technological advances yet to be fully harnessed in sprint disciplines the likes of Usain Bolt’s 100m world record looks safe for now. Nike’s innovative Viperfly sprint spike unveiled last year is believed to have produced significant improvements in testing but did not adhere to World Athletics regulations and has now been ditched having never been used in competition.
A new legal version may yet appear before the Olympics, and New Balance - whose Fuelcell SDx spikes have helped Holland’s Femke Bol run the four fastest 400m times in Europe this year - also have designs on making a new short sprint spike legal by the Tokyo Games.
Coe, who set 12 world records during his career, remains sanguine - publicly, at least - about complaints that the spikes make a mockery of comparisons with previous eras, insisting, “we shouldn’t be in the business of trying to suffocate innovation”.
He said: “I don’t think we've reached that point where world records are being handed out like confetti. World records do matter. They need to be cherished. They need to be things that the world looks at and thinks, ‘That’s a new benchmark, and a suffusion of skill, talent, hard work and great coaching’.
“There have been some technological advancements on what I was running in and what the generation before me was running in. If I slide down the ranking list, that’s the nature of sport.”
One field of thought is that the new spikes will allow some suspect performances to be wiped from the record book with a preference for shoe-aided times over those potentially fuelled by performance-enhancing drugs.
The implications could also be far wider than reducing elite times. Hoogkamer says the money that shoe companies input into training biomechanists will allow them to “help people with strokes to walk better, or find better prosthetics for people”.
Others have pointed out that not only does the improved footwear help people with injury-prevention, but it also generates more interest in running and being active. “It’s beneficial for everyone,” says Hugo Chouissa, Brooks footwear merchandiser.
Well, almost everyone. The record holders of yesteryear may well think differently.
