Josh Kerr made history on Saturday at the London Diamond League, running 3:42.66 to break Hicham El Guerrouj’s legendary world record in the mile (3:43.13) from 1999.
Kerr, a two-time Olympic medalist from Great Britain, announced his plans to go after the record in March, and since then, he’s steadily built anticipation for the event. Every step of the process was done with intention. He structured his season to peak for the race. He chose London because he wanted to race in front of a home crowd. His sponsor, Brooks, created a bespoke pair of spikes and speedsuit for him, specifically designed for the record attempt.
By unveiling the attempt four months before the race, there was a risk for things to go wrong. But one thing was for sure: Kerr knew he was fit enough to break the record.
At the prerace press conference on Friday, a reporter asked Kerr if there was a specific training session that made him believe the world record was possible.
“I believe at 6 p.m. or 7 p.m. tonight, you guys will get a little treat,” Kerr said with a cheeky grin.
That “treat” turned out to be a video on Kerr’s YouTube channel titled, “World Record Time Trial.”
In it, the Scotsman is paced by Brooks Beasts teammate Brannon Kidder during a 1200-meter time trial (three laps of a 400-meter track). The session, which took place on July 3, was the “biggest workout of the build-up,” according to the video’s description.
Kidder and Kerr averaged 55-second laps for the first 800 meters—right at mile world record pace—then Kerr took over for the final lap, closing in a ferocious 51.88 seconds.
His final time, 2:42.45, is unofficially the fastest 1200 meters in history.
What made it even more impressive was that Kerr ran the time trial in Albuquerque, New Mexico, which sits at about 5,300 feet of elevation, meaning he likely could have run a few seconds faster at sea level.
At this point, Kerr knew he was ready. After the workout, he walked around the track amped up, noting that he only needed a 60-second lap to break the world record (plus another nine meters to account for the full 1609 meters in a mile).
“You think I can’t run a 60 right now?” he joked.
Kidder, who would go on to pace Kerr through 800 meters in 1:50.70 on Saturday, was equally as hyped.
“Holy shit, dude. You got it.”
Despite announcing the world record attempt in March, Kerr has raced sparingly during the outdoor season. He ran two good-but-not-earth-shattering 800-meter races in May and June, but he never lined up for a competitive 1500 or mile, instead prioritizing a long training block.
But the 1200 was hard to ignore.
Even Tim Hutchings, who called Kerr’s race on Saturday on the world feed, admitted that the 1200-meter time swayed his view on Kerr’s chances.
“I must admit, that turned my opinion,” he said, moments after Kerr broke the record. “I was 50/50 that he would get this today. And then I heard that he ran [2:42] for a 1200 and I thought, ‘No, it’s 75 percent likely now.’”
At the end of the YouTube video, Kerr says he wanted to walk away from the time trial like it was no big deal.
But after taking down one of the most iconic records in the sport, he deserves to celebrate like it’s 1999.
Theo Kahler is the senior news editor at Runner’s World. He’s a former all-conference collegiate runner at Winthrop University, and he received his master’s degree in liberal arts studies from Wake Forest University, where he was a member of one of the top distance-running teams in the NCAA. Kahler has reported on the ground at major events such as the Paris Olympics, U.S. Olympic Trials, New York City Marathon, and Boston Marathon. He’s run 14:20 in the 5K, 1:05:37 in the half marathon, and finished 40th at the 2025 New York City Marathon. He enjoys spotting tracks from the sky on airplanes. (Look for colorful ovals around football fields.)
