Tell me about the Vaporfly shoe controversy.

 

The Vaporfly Shoe Controversy

A genuinely interesting episode in the recent history of the sport — and one where I should search for the most current state of the regulations, since this has continued to evolve.Good — I have what I need. Let me give you the full picture.

What the Vaporfly Actually Is

The Nike Vaporfly is a road-running shoe whose key innovations are a thick midsole of an ultralight, highly elastic foam (Nike calls it ZoomX), a curved carbon-fibre plate embedded in that foam, and a "rocker" geometry that tips the runner forward. The combination dramatically improves running economy. A study published in 2017 demonstrated that such shoes were 4% more efficient than several of their competitors, which is where the original retail name — Vaporfly 4% — came from.

A 4% improvement in running economy is enormous. To put it in perspective, it is larger than the gain most elite marathoners would get from a year of optimised training.

The Timeline

February 2016 — first sighting. At the U.S. Olympic Marathon Trials in Los Angeles, three Nike athletes — Galen Rupp, Amy Cragg, and Shalane Flanagan — made the Olympic team wearing unusually thick Nike shoes. No one knew anything more about these strange, unnamed shoes.

August 2016 — Rio Olympics. At the 2016 Rio Olympic Marathon, the top three men finishers all wore the new, unnamed Nike shoe. The shoe was still a prototype, not on sale to the public.

May 2017 — Breaking2. Eliud Kipchoge ran an astonishing 2:00:25 in Nike's Breaking2 exhibition on a car track in Monza, Italy. He wore a thick, rockered shoe named the Vaporfly Elite.

November 2017 — published evidence. A group of Nike researchers and University of Colorado biomechanists published a paper in Sports Medicine investigating the economy of runners in the Vaporflys vs. traditional racing shoes. The Vaporflys conferred approximately a 4 percent advantage — confirming what observers had begun to suspect from race results.

2018–2019 — record cascade. Brigid Kosgei broke Paula Radcliffe's 16-year-old women's world record at the 2019 Chicago Marathon by 81 seconds, wearing Vaporflys. Kipchoge ran 1:59:40 at the INEOS 1:59 Challenge in Vienna in October 2019 wearing prototype Alphaflys with three carbon plates and dual Zoom Air pods. 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.

January 2020 — the data forces a reckoning. A German sports scientist, Helmut Winter, published an analysis of best marathon times finding that 2019 had roughly twice the number of fast times vs other years. The top men were about 1:45 faster, and the top women about 3:00 faster, than in prior years. Around the same time, athletes wearing them took 31 of the 36 top-three finishes in the Marathon Majors series in 2019.

The Ruling — January 31, 2020

World Athletics established a working group and issued amended rules just before the Tokyo Olympic year. The previous rule had been almost uselessly vague — that shoes "must not be constructed so as to give athletes any unfair assistance or advantage". The new rules were specific:

• road shoes must have soles no thicker than 40 milimetres and not contain more than one rigid plate.
• From April 30, any shoe used in competition must have been generally available to the public for four months — ending the prototype era.
• Any shoe that is introduced to the open retail market would have to remain available, in the spirit of universality.

The crucial outcome: The Nike VaporFly Next% shoes have a stack height of 40mm, which would meet the limit. The retail Vaporfly was preserved. The triple-plated Alphafly prototype Kipchoge had used in Vienna was banned.

Why It Mattered Beyond the Shoe

Three deeper issues, which is why this episode keeps getting cited:

Concentration of competitive advantage. From 2017 onward, athletes not sponsored by Nike faced a stark choice: break sponsor contracts, or race in shoes that were demonstrably 4% slower. Running has moved from being a footrace to an arms race. Other manufacturers — Adidas, Saucony, Asics, Brooks, New Balance, Hoka — scrambled to bring competitor shoes to market. By the time of the ruling, most had at least prototypes.

The "technological doping" framing. Critics, including Yannis Pitsiladis, a professor of sport and exercise science at Britain's Brighton University, calling them "technological doping", argued the shoes crossed a line between equipment and performance enhancement. The defence was that no rule was being broken and the technology was now becoming widely available. The harder question — what should a rule say? — is what the new regulation was an attempt to answer.

The Sebastian Coe conflict. It is worth noting plainly: Nike is a major sponsor of many of the world's track and field events at every level of competition. Nike sponsors a number of athletes, USA Track & Field, and has even sponsored the president of World Athletics, Sebastian Coe, since 1978. The decision-maker had a direct, decades-long financial relationship with the manufacturer whose shoe was being regulated. The ruling — drawing the line just above the retail Vaporfly while banning the unreleased Alphafly — was viewed by some critics as suspiciously well-suited to Nike's commercial interests. The 40mm threshold preserved Nike's existing market leadership while preventing further unilateral escalation.

What Happened Afterward

The era of "super shoes" did not end — it became universal. After adjusting to the new rules, Nike released the Alphafly 2, which Kipchoge wore at the 2022 Berlin Marathon to set the official world record of 2:01:09. Kelvin Kiptum then ran 2:00:35 at the 2023 Chicago Marathon in the Alphafly 3. Tigst Assefa set the women's world record (2:11:53) at the 2023 Berlin Marathon in Adidas Adios Pro Evo 1, a single-use racing shoe. By the mid-2020s every major manufacturer had a carbon-plated shoe; the gap that had distinguished Nike-sponsored athletes was closed.

Two side-effects worth noting. First, the rules apply to elite competition; recreational runners can wear what they like. Second, the post-2020 women's records have fallen unusually fast, raising the question of whether the previous era's records were partly held back by training and entry barriers that the technological era's fresh attention has helped to expose.

The Constitutional Reading

To return briefly to where we started: the Vaporfly episode is the cleanest recent example of why the marathon's governance architecture is a polycentric compact rather than a sovereign authority. No one had a rule for this. The rule had to be made under pressure, in public, with the regulator visibly conflicted, the dominant manufacturer setting the pace of innovation, and the affected athletes — across many federations and sponsors — needing the outcome to be legitimate enough to keep racing under it. The line they drew was not philosophically clean. It was 40mm and one plate, set just above the shoe Nike was already selling. It worked, in the rough sense that the sport continued. Whether it was a stewardship action or a hegemony moment is genuinely contested — and that, on the framework's own terms, is what governance under uncertainty looks like when no one is in charge.