Breaking4

Breaking4 was an attempt by Kenyan middle-distance runner Faith Kipyegon to become the first woman to break the four-minute barrier for the mile. Hosted by Nike, the event took place on 26 June 2025 at the Stade Sébastien Charléty in Paris, France.¹

Kipyegon fell 6.91 seconds short of the four-minute barrier with a time of 4:06.91, still under her official world record by 0.73 seconds.

Nike later subtracted the reaction time, adjusting her official time to 4:06.42.²³

In 1954, Roger Bannister became the first man to break four minutes in the mile, running 3:59.4.⁴⁵ That same year, Diane Leather became the first woman to break five minutes with 4:59.6.⁶ As of June 2025, according to World Athletics statistics, roughly 2,000 men have broken the four-minute barrier.⁷

No woman has yet broken four minutes. The women's world record is 4:07.64, set by Kipyegon on 21 July 2023.⁸ An earlier women's world record, 4:12.56 set by Svetlana Masterkova of Russia in 1996, stood for almost 23 years, with Masterkova being the first woman to break 4:15 at the distance.

Kipyegon also holds the world record over 1500 metres, which at the time was 3:49.04, set in 2024, at the Stade Sébastien Charléty.^{note 1} The time equates to roughly a 4:06 mile pace.⁹ Kipyegon's run has led some to speculate that the first women's sub-four minute mile may come within the 21st century.¹⁰

In January 2025, at the Nike Headquarters in Beaverton, Oregon, Kipyegon did VO2 max testing along with other baseline tests in preparation for the attempt.¹¹ In February 2025, a scientific study was published in the Royal Society Open Science, stating that Kipyegon could run a mile in approximately 3:59.37 under very specific conditions, achieved through ideal pacesetters and weather conditions.¹²¹³

In April 2025, it was announced that Kipyegon would attempt to become the first woman to run a sub-four-minute mile at a meeting in Paris on 26 June 2025.¹⁴

The event was run in a similar manner to Nike's previous Breaking2 project for the marathon and the Ineos 1:59 challenge.¹ It was not record eligible because the custom pair of Victory Elite FK spikes Kipyegon wore were not submitted for approval by World Athletics prior to the event.¹⁵¹⁶

In addition to the spikes, Kipyegon wore a specially designed speed suit and sports bra.¹⁴⁹

To break the barrier, she would have to improve on her 4:07.64 personal best by at least 7.65 seconds.⁶ Kipyegon fell 6.91 seconds short of the four-minute barrier with an unadjusted time of 4:06.91, which is still faster than her official world record by 0.73 seconds.²³

Breaking4 utilized a dozen male and female pacemakers:¹⁷

On 26 April 2025, Kipyegon ran 2:29.21 for 1000 metres at the Xiamen Diamond League, a time 0.06 seconds off her personal best of 2:29.15 and 0.23 seconds off Svetlana Masterkova's world record of 2:28.98. This time equates to a 4:00.08 mile pace. Robert Johnson of LetsRun.com considered the attempt to be "ludicrous", since Kipyegon would be required to hold a slightly faster pace for approximately 609 metres longer.¹⁸¹⁹

A scientific paper published in the Journal of Applied Physiology in April 2025 concluded that "there is no female athlete presently displaying the physiological characteristics required to run a sub-four minute mile".¹¹²⁰

The event was streamed live on Prime Video and Nike's YouTube channel, beginning at 7:15 PM local time. The first episode of a docuseries covering the event premiered on 20 June.⁹