Josh Kerr’s Coach Knows The Number That Will Break The Mile World Record

Josh Kerr will attack the mile world record at London Stadium on Saturday, and a new behind-the-scenes film from FloTrack reveals the number his coach has been building the entire attempt around.

“If he can be in 1:43 shape by July 18th, then that’s one of the factors he’ll need to be hitting to be ready to run the world record in a mile,” Danny Mackey, Kerr’s coach of nearly a decade with the Brooks Beasts, says in the video. “I feel confident with this plan. He’ll be prepared for July 18th.”

The record Kerr is chasing has stood for 27 years. Hicham El Guerrouj ran 3 minutes, 43.13 seconds in Rome in 1999, a mark that has outlasted an entire generation of milers. Kerr’s British record of 3:45.34 sits sixth on the all-time list, and his target, per the name of his Project 222 campaign, is 222 seconds. That is a 3:42 mile.

A Tune-Up Where Place Mattered More Than Pace

The film follows Kerr and Mackey through their last racing weekend before London, at the USATF LA Grand Prix on June 14, exactly 34 days out from the attempt.

The original plan for Kerr’s 800 meters was to run 1:43 and win. Then Mackey watched the wind readings for two days and studied the track’s tight turns, and the brief changed. “In Josh’s situation, it might come down more to who he beats versus what time he runs,” he says in the video.

Kerr made what Mackey called “an audible mid-race” and finished fourth in 1:45.46, one spot behind former world 800m champion Donavan Brazier, as Brandon Miller won in 1:43.94.

Neither coach nor athlete flinched at the result. “I was hoping to obviously run a little bit faster today, but my biggest goal for today was to run hard,” Kerr says. “It’s another day that my body showed up exactly how I thought it would.”

Racing A Clock For The First Time

The video captures something Kerr has never done in a career defined by championship racing, where Mackey says an athlete “needs to be ready for three or four different things.” This buildup has one scenario.

“I’m racing a clock and a time versus an individual,” Kerr says.

“This is the first time we’re trying to run a specific time and have it be really regimented,” Mackey adds. “We generally know what he needs to run July 18th, so we’re really specific in workouts, targeting that type of pace.”

At the time of filming, Mackey said “one or two really hard workouts” remained in the buildup. Marathon Handbook has since covered one of them, a 4,000-meter session at world record pace with three weeks to go.

The project is also an answer to how Kerr’s 2025 ended. He suffered a calf injury midway through his world 1500m title defense in Tokyo and limped home last. “I was a little curious how he’d bounce off that,” Mackey says, but Kerr was quick to ask for an outdoor season pointed at the record. The buildup since has been unusually public, from sleeping in an altitude chamber to a video series starring his own family.

“I Hope He’s Elated”

The film’s most disarming moments belong to Mackey. “He’s one of these athletes where I wish that time kind of froze so I could coach him forever,” he says. He credits Kerr’s steadiness to the fact that “his identity is not attached to the sport, so he’s really secure about whatever the result’s going to be.”

“If there’s something beyond the record that I’d like him to have, it’s just some joy and fun,” Mackey says. “This might be the only time in his career where he can focus on trying to be a world record holder and not have to worry about other races. So I hope he’s elated.”

Kerr, 28, gets his answer on Saturday evening in the Emsley Carr Mile at the Novuna London Athletics Meet, where Yared Nuguse has joined the field and US viewers can watch live on FloTrack.

“There’s no guarantees in this sport other than I’m going to give my full effort on that day, July 18th,” Kerr says. “And whatever that result is, I believe it can be a world record.”