One of the most important universal beliefs in the world of sports is that competition should always be fair. No cheaters allowed! And those who are caught swindling at the highest levels are only ever remembered for how they shamed their respective sport. The use of special equipment, performance enhancing drugs, betting on games, or any other way of rigging the system in sports is a big no-no.
One of the aspects of sport that has often been the centre of controversy is footwear. After all, it makes sense that an object that connects an athlete’s feet to the ground should have attention paid to it and regulations imposed on it if necessary. Throughout the years, athletes and/or brands have come under fire for shoes that were deemed unfair due to advanced technology or special design that gave the wearer some type of leg up. Or sometimes the shoes were just simply given the heave-ho because they were in the wrong colours. With that in mind, let’s take a look at some of the biggest controversies surrounding performance footwear throughout the years.
Nike Vaporfly/Alphafly Series
Nike's Vaporfly kicked off the ‘super shoe’ war, where multiple brands are trying to best each other with technology to make the fastest running shoes, but it also got booted out of comps for being too good. The footwear in the Vaporfly/Alphafly series is characterised by a combination of Nike’s lightweight, energy-returning ZoomX foam and at least one carbon fibre plate in the midsole. The foam and carbon fibre work together to cushion each stride, return the energy, and propel the runner forward with a sensation that’s more like running downhill than on a flat surface. Sounds great, right? But the powers that be in the sports world deemed Nike’s super shoes to be a little too super.
After Kenyan runner Eliud Kipchoge fell just short of finishing a marathon in under two hours while wearing the Vaporfly Elite at Nike’s Breaking2 event in 2017, he tried again two years later in an event dubbed the INEOS 1:59 Challenge in Vienna, this time wearing a prototype of the Alphafly Next% with stacked ZoomX, three carbon fibre plates, and dual Zoom Air pods in the forefoot. The marvel of running shoe engineering helped Kipchoge achieve his goal, finishing the 26.2 miles in an astonishing time of 1:59:40. But Kipchoge’s record was not acknowledged by World Athletics, the international governing organisation that regulates track and field sports, because rules for pacing and fluids were not followed and it was not an open event for others to compete in. There was also speculation that it was mainly his tricked-out Nikes that jetted him to a sub-two hour time. Although never mentioned specifically, Kipchoge’s Alphafly is almost certainly what prompted World Athletics to set new rules for running shoes in competition. Highlights of the rules established in the spring of 2020 pertaining to road running shoes include that the sole height may not exceed 40mm, only one rigid structure (i.e., carbon fibre plate) is allowed in the midsole, and the shoes must be available for purchase by anyone participating in the applicable competition (no prototypes).
The Alphafly was banned ahead of the 2020 Olympics, but it wouldn’t be the end for Nike’s speedsters. After adjusting to the new rules, Nike released the Alphafly 2, which Kipchoge wore when he made headlines again in 2022 as he set a new, accepted world record of 2:01:39 at the Berlin Marathon. Then at the 2023 Chicago Marathon, Kenyan runner Kelvin Kiptum shattered Kipchoge’s record by finishing in 2:00:35, wearing the Nike Alphafly 3.
adidas Adizero Prime X 2 Strung
Despite the new regulations set by World Athletics in 2019 on performance running shoes for competition, brands still continued pushing the limits of their running footwear tech. In fact, most running shoe brands have leaned into the banned status of certain tech, and a new category of ‘illegal’ running shoes has emerged for training purposes. The new ‘super trainer’ category is characterised by models with any or all of today’s running shoe cheat codes including rocker soles, advanced foam stacked to heights 40mm or taller, and rigid plates within the midsole. Proponents of super trainers claim that the extra cushioning helps recovery time after runs, and even allows them to increase their mileage since running is literally easier. Critics say that a shoe shouldn’t make running that much easier.
One of the headliners of the outlaw footwear is the adidas Adizero Prime X 2 Strung. adidas themselves boasted about this shoe being illegal in their press release debuting the model in September 2023. The towering running shoe features two carbon-infused plates surrounded by three layers of the brand’s Lightstrike Pro foam stacked to an imposing height of 50mm. That’s 10mm taller than what the World Athletics guidelines allow, and significantly taller than other super trainers currently on the market that usually measure in at about 40-45mm. For anyone looking to shave some time off of your personal best – or just appear a little taller – the Adizero Prime X 2 Strung is currently available for $300.
adidas Adizero Adios Pro Evo 1
The Three Stripes have another super shoe that caused a stir, but not for how tall the midsole was or because it had too many carbon fibre plates. Released in 2023, the Adizero Adios Pro Evo has been criticised for its ‘single use’ construction designed specifically for a runner to wear for only one race. adidas describe the shoe as their lightest long distance running shoe ever, as it is 40 per cent lighter than any race shoe they’ve ever created at just 4.87 ounces. The design features a thin, featherlight mesh upper and thick Lightstrike Pro midsole that measures in at 39mm. The idea behind the flimsy design of the shoe is to reduce weight as much as possible, in theory making the runner faster. Produced in limited quantities, the Adios Pro Evo 1 is priced at $500 and even comes with a disclaimer card in the shoe box that it is not meant to be worn by anybody with a marathon time over 3.5 hours. But the fragile racing shoe has drawn criticism from many who say a single use shoe is wasteful and not environmentally conscious. A group known as the Green Runners even penned an open letter to adidas, asking them to cease production of the Adios Pro Evo 1:
‘A shoe designed to last one marathon race. Is this the ultimate in single-use madness? For many years people have campaigned against single use plastics. And slowly, too slowly, governments are paying heed… but who would have thought that a major sports brand would have the audacity to market a single use running shoe? We didn’t.’
Despite the controversy, the ultra lightweight shoe seems to work. At the 2023 Berlin Marathon, Tigst Assefa of Ethiopia wore the Adios Pro Evo 1 while setting a new women’s world record of 2:11:53, more than two minutes faster than the previous record.
Nike Air Ship/Air Jordan 1
Perhaps the most famous ‘banned’ shoe of all time is the Air Jordan 1 in its original black and red colourway, despite the fact that it was never actually the shoe Michael Jordan wore that led to the ban. As the story goes, Nike didn’t quite have the Air Jordan 1 ready in time for Michael Jordan to wear during the NBA preseason and early portion of the regular season for his rookie year in 1984. While the Jordan 1 was still in production, Jordan laced up a similar, existing model, the Air Ship. The problem was that a certain black and red colorway of the Air Ship that he wore during the preseason in October – in a similar colour block as the ‘Bred’ Jordan 1 you know and love today – didn’t meet the NBA’s uniformity rules, which at the time declared that a player’s shoe had to be at least 51 per cent white. Part of the lore of this story is that the league issued a letter to the Chicago Bulls and/or Nike stating that Jordan would be fined each time he wore the shoe – although this has never been proven with any official documentation.
As far as existing photo evidence has proven, and despite what Nike’s longtime marketing story has led the world to believe, Jordan did not continue wearing the black and red Air Ship or Jordan 1 in games, instead switching to white versions of the Air Ship with red or grey accents, and then the ‘Chicago’ and ‘Black Toe’ Jordan 1s throughout the 1984-85 season.
APL Concept 1
In 2010, an upstart footwear brand Athletic Propulsion Labs, or APL for short, released the Concept 1 basketball sneaker featuring something they call ‘Load ‘N Launch’. The technology features a spring-based device in the forefoot of the shoe that compresses and releases when the athlete pushes off their foot to jump. From APL: ‘The device features unique compression properties designed to provide an instant rebound effect that is transferred up through the foot to enhance vertical leap.’
APL claims that the Load ‘n Launch system can add up to 3.5 inches to the wearer’s vertical leap. The Concept 1 was banned by the NBA in 2010 for being deemed to give an unfair advantage. Of course, the controversy actually helped APL sell more shoes. Today APL isn’t exactly disrupting the athletic footwear market with their springy sneakers, but they are still in business. You can buy an updated version of the Concept 1 called the Superfuture, as well as running shoes that feature Load ‘N Launch.
Serafino 4th Edge
In 2015, upstart football boot brand Serafino released a model unlike anything anybody on the pitch had seen before. Sporting a comically shaped flat toe extension, the oddball design was intended to improve the power and accuracy of toe pokes. The 4th Edge was the brainchild of Australian fashion designer and entrepreneur John Serafino, who launched the flat-toed boot with the help of a Kickstarter campaign and eventually got respectable football players including Harry Redknapp, Nigel Clough, and Glenn Hoddle to back the design. Apart from looking pretty goofy, the 4th Edge was criticised for giving players wearing it an unfair… edge.
Serafino eventually also tried toeing their way into American football for use by kickers and punters, with mostly failed results, and today the brand is defunct. We know, you’re shocked to hear that
adidas Predator Series
The adidas Predator series is now one of the longest running, most popular lines of football boots ever, but when it first launched in 1994, there was plenty of controversy surrounding the design. That’s because the Predator debuted the use of a textured rubber layer on its upper, which adidas claimed would provide better grip and ball control, as well as more swerve and power when shooting. Although it was never really proven that the rubber layer with a fin-like texture significantly helped the wearer to control the ball better, critics said the Predator provided an unfair advantage. adidas leaned into the controversy with an ad campaign that proclaimed the Predator ‘100% Legal, 0% Fair’. Eventually the rubber layer was phased out, but the Predator series lives today as adidas’ fiercest football boots.