History was made last Saturday morning in Vienna as Eliud Kipchoge broke the two-hour barrier in the marathon, a feat once thought impossible, running a time of 1:59:40—over a minute faster than the world record he ran in Berlin in September of last year. Despite being the fastest marathon time ever recorded, the time won’t be officially recognized as a world record because it wasn’t run in open marathon conditions and didn’t align with record regulations. Pacing aids were used, with an electric car leading the rotating pacemakers at a constant speed, providing a break in headwind while ensuring precise and even splits. In addition to those carefully planned factors, Kipchoge controversially raced in a prototype of Nike’s AlphaFly shoe, with experts claiming that the shoe provided an unfair advantage. Despite the criticism that Kipchoge received from wearing the shoes, what he accomplished is still of immense magnitude.
Kipchoge’s use of the shoe in his sub-two hour marathon has been heavily denounced, as experts claim that the shoe provides an unfair advantage and the improved midsole could be compared to springs, with two exposed and two hidden airbags sandwiched between three carbon fiber plates. The AlphaFlys are rumored to have up to a five percent performance gain, and the Vaperflys, the older version of the shoe, have been proven by a team at the University of Colorado’s Locomotion Laboratory to provide more energy return and shorten marathon times by four percent. Some experts have attributed the performance to the shoes and the legitimacy of such shoes have recently been heavily investigated. As scientists continue to innovate and improve running shoe performance, the question of whether to limit the stack height or material usage arises.
Hours after Kipchoge’s monumental marathon on Saturday, Brigid Kosgei of Kenya set a new world record for women’s marathon with a time of 2:14:04 at the Chicago Marathon, besting Paula Radcliffe’s record by 81 seconds, which has stood since 2003. She was also wearing the Nike Vaporfly Next%, a last minute choice inspired by Kipchoge. Kipchoge wore the same shoes in his world record that he ran in Berlin. While the Next% shoes are commercially available, her achievement was also heavily scrutinized, as some credit her success compared to past personal best times and the impressive improvement from the previous world record to the shoes.
The International Association of Athletics Federation (IAAF) is the governing body for various running-related events. Its current rules loosely state that the shoes “must not be constructed so as to give athletes any unfair assistance or advantage.” With Nike’s new, superfast shoes in the marathon-racing scene, the IAAF has been considering changes to the rules. Experts have called the shoes a form of “technological doping,” and there has been talk of how the shoes provide a mechanical advantage to those wearing it, with its thick midsole increasing running economy. However, this is just the latest technological development in the running shoe industry, and the actual shoes are not providing any bonus assistance to the runner.
With two legitimate world records tied to the Nike Vaporflys, the shoes has been under heavy scrutiny. Ryan Hall, a retired professional runner who holds the US half marathon record, claimed that these shoes create an “uneven playing field.” However, other brands have created their own models, with Hoka One One being the first to follow in Nike’s lead by reconstructing the midsole of its shoes. Saucony and Brooks have also developed their own versions, and Des Linden wore a prototype of a Brooks racing shoe with carbon fiber plates when she won the Boston Marathon in 2018. All major brands are developing their own version of Nike’s AlphaFlys, continuing to seek more efficient shoes that allow elite runners to run even faster.
Kipchoge’s performance was immense regardless of the criticism he received for the shoes. The Nike shoes he wore only helped him run more efficiently—they didn’t add speed that wasn’t already there and do not detract from his performance. Kipchoge proved that it is possible for a human to break the two-hour barrier, and there’s no doubt that others will follow in his steps. The original four-minute mile barrier stood for decades, but once broken in 1954 by Roger Bannister, Australian runner John Landy ran 3 minutes and 58 seconds just 46 days later. As scientists continue to develop more efficient shoes, it’s exciting to see when others will join Kipchoge in the exclusive sub-two club.