Thu, June 26, 2025
Faith Kipyegon sparks discussion on sport integrity as she attempts to break the four-minute mile barrier using new, unapproved technology
Kenyan middle-to-long distance runner, Faith Kipyegon, is attempting to be the first woman to run a mile in under four minutes with the help of new, unapproved technology, sparking discussion on sport integrity and accessibility.
Today, 31-year-old Faith Kipyegon will attempt to shave 7.65 seconds off her 4:07.64 women’s mile world record achieved in 2023 to “cement her legacy.” Everyone from physiologists to shoe designers have collaborated to discover ways to help her trim every hundredth of a second possible—some of which make the run ineligible for official world records, according to National Geographic.
Time Zone & Altitude
The event will be held at the Stade Sébastien Charléty in Paris around 7:15 CEST today. Paris only has a one-hour time difference with Kenya so less adjustment is required. Additionally, Paris is only 115ft above sea level; Kipyegon trains nearly 8,000ft above sea level. When you train at high altitude and then return to low altitude, “you've sort of got an extra scuba tank; you can deliver more oxygen to your muscles,” as said by Rodger Kram from the Integrative Physiology Department at the University of Colorado.
Weather, Stadium & Pacers
Regarding the weather, “the temperature and the humidity are relatively unimportant, as long as it’s reasonable [as it should be in Paris],” says Kram. The LED track in the stadium provides shock absorption and energy return. A Wavelight pace-setting system is also installed, meaning 400 computerised lights surrounding the track’s inner curb will set an automated pace for Kipyegon. Furthermore, this stadium is where Kipyegon set the 1500m world record last July, so it should provide a huge mental boost.
Kipyegon will also be paced by male and female Olympians. This includes Great Britain’s Gemma Reekie, Georgia Hunter Bell and Elliot Giles. They will shield her from the wind as she runs 15 miles an hour. They will reduce aerodynamic drag, allowing her to run quicker without using more energy.
In a study published by the Royal Society Open Science, Kram argued that it was possible for Kipyegon to run a mile in 3:59.37 if she placed a pacer exactly four feet in front of her and a second running exactly four feet behind her. This is because the rear pacer pushes air into the back of the runner, propelling her ever so slightly forward. Eliud Kipchoge utilised this method and became the first person to run under 2 hours for the marathon.
New Shoe Design
Additionally, Nike has designed ultralight track spikes specifically for this attempt. Each shoe weighs around 85 grams, 25-percent lighter than the shoes she wore to break the mile world record 2 years ago. The upper of each spike is as light as three paperclips and is woven from a new, proprietary yarn that’s never been used in a shoe before. Proprietary yarn refers to a type of yarn developed and produced using a company's own unique technology or process, often with specific characteristics or performance attributes.
As Kram discovered, for every 100 grams deducted from a shoe’s weight, the energy cost to the runner drops by about 1 percent. And each 1-percent decrease in energy cost translates to 2/3 of a percent increase in speed. Nike also added an ‘Air Zoom’ unit under the forefoot that’s three millimetres taller than in her previous shoe, which will enhance energy return.
New Kit Design
Nike has designed a suit for Kipyegon too. The suit features thousands of ‘Aeronodes’ – tiny bumps – which are designed to smooth out “noisy” air, as designer Lisa Gibson describes it. Kipyegon will also wear a custom-made 3D-printed bra composed of ultralight thermoplastic. A mannequin which produces artificial sweat was used to test the breathability and moisture-wicking properties of the clothes Kipyegon will wear during the attempt.
“This 3D-printed material innovation represents something entirely new on a visual and visceral level,” expressed Janett Nichol, Vice President, Nike Apparel Innovation. “Sports bras have never looked or felt like this before. The material is soft, light and incredibly supportive — yet it also feels like you’re not wearing anything at all. We know Faith’s bringing everything she has to achieve this goal, so we knew Nike FlyWeb had to be part of our contribution.”
Integrity Issues
Even though Kipyegon’s attempt will not officially count due to the use of new technology and male pacers, some argue that the event has called into question the accessibility, fairness and integrity of athletics. Recently, World Athletics established a Request for Proposal covering two services that concern its athlete shoe regulations, suggesting it is taking such concerns seriously, but Breaking4, the name Nike has given to Kipyegon’s attempt, has brought into question the future of the sport.
However, Nike has contended this with the following statement: “Of course, the most important component in Breaking4 isn’t futuristic apparel or a cutting-edge spike, but Kipyegon herself. The Nike products are designed in service of her; they’re boundary-breaking because of her. And their every consideration — of which there were hundreds, thousands — had to bring Kipyegon an unrivalled confidence in her movement, her body and her preparedness to take on the record of a lifetime.”
“One of Faith’s unique qualities as an athlete is to bring out a spirit of connection among individuals, who all come together to achieve new heights,” says Kirby, Principal Researcher, Nike Sport Research Lab. “Through the camaraderie she brings, we all achieve something greater than what we could do alone. When she suits up for this attempt, we’ll all be there alongside her.”
The attempt is expected to take place at 7pm BST on 26 June 2025 and will be broadcast live on Nike's YouTube and Instagram, with coverage beginning from 6.15pm BST.
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