Josh Kerr Breaks Mile World Record With Amazfit

Amazfit today congratulated elite athlete partner Josh Kerr on setting a new men’s mile world record at the London Diamond League, completing Project 222—his public pursuit of a 222-second, or 3:42, mile.

Kerr finished in 3:42.66, surpassing Hicham El Guerrouj’s previous record of 3:43.13, set in 1999. The result is pending official ratification by World Athletics.

The performance followed months of structured training, recovery monitoring and performance analysis with his coach, Danny Mackey, supported by Amazfit technology. Paced through the first three laps by training partners Brannon Kidder and Žan Rudolf, Kerr passed 800 meters in 1:51.1 and 1,200 meters in 2:46.4—almost exactly on world-record pace—before pulling away from American Yared Nuguse on the back straight of the final lap. Kerr crossed the finish in 3:42.66, closing his final 409 meters in 56.27 seconds, including a 16.27-second last 109 meters, as Nuguse settled for second in 3:45.69.

“The last 100, this stadium was absolutely bouncing in here. If you want to affect a generation, and do it for your people, then you have to do it in your home—that’s the legacy I want to leave,” said Kerr. “If I am to leave my mark on this sport as a British legend, following in the footsteps of the legends behind me, I have to put in those performances.”

Ahead of the race, Kerr described the attempt as a pursuit of complete preparation and total focus.“That’s what I’m chasing with this record: full flow,” Kerr said. “I’ve done every single thing I can, and I’m now giving my body and my mind over to this experience.”

Watch Kerr discuss the record attempt and his preparation here.

Turning Race Data Into Insight

Kerr wore a custom Amazfit Cheetah 2 Pro during the race to capture performance data including heart rate, pace, splits, cadence and stride length. Following the race, Kerr and Mackey reviewed the activity in the Zepp App to assess how closely the performance matched the race plan.Key data included:

• Final time: 3:42.66
• 400-meter splits: 400m – 55.3 | 800m – 1:51.1 (55.8) | 1,200m – 2:46.4 (55.3) | 1,500m – 3:27.62 (PB) | Finish (1,609m) – 3:42.66
• Average and maximum heart rate: 178 bpm and 188 bpm
• Average cadence: 194 steps per minute
• Final-lap data: Final 409m in 56.27 seconds (last 109m in 16.27)

The official splits show Kerr matched his target almost exactly: 55.3, 55.8 and 55.3 seconds for the first three laps, putting him through 1,200 meters in 2:46.4—inside world-record pace. He then covered the final 409 meters in 56.27 seconds, including a 16.27-second closing 109 meters, and passed 1,500 meters in a personal-best 3:27.62. Stride length reached a max of 2.2 meters, while cadence increased to 199 during the final 16 seconds.

For Kerr, wearable data is not a scorecard. Its value is in identifying trends, creating accountability and helping athlete and coach make better decisions. “The watch is so important to get the data right and to be able to track everything,” Kerr said. “Things do not need to go perfectly, but you need to track what you’re doing.”

“We had a number in mind for months, and Josh hit it,” said Mackey. “The wearable data gave us the confidence to know he was ready. The rest was just him going out and doing the work.”

A Custom Watch for a Historic Attempt

For the record attempt, Kerr wore a custom Amazfit Cheetah 2 Pro featuring diamonds and a 10K gold-dipped bezel, paired with a custom Project 222 Helio Armband. During the race, the Helio Armband captured continuous heart rate data, giving Kerr and his team a detailed view of his effort and performance.

The Helio Armband also played a central role throughout Kerr’s preparation, helping him monitor sleep, heart rate variability, resting heart rate and broader recovery trends. Combined with the Cheetah 2 Pro and Zepp App, it gave Kerr and his team a more complete view of his training, recovery and race-day performance without requiring a subscription.

Recovery and Consistency

Sleep is the recovery metric Kerr watches most closely. His goal is approximately eight hours overnight, along with a 90-minute daytime nap.

“Our goal is to get eight hours of sleep a night and then for me to get about an hour and a half during the day,” Kerr said. “If I’m firing like that, then training is not a problem.”

Kerr uses sleep and HRV trends to guide decisions without overreacting to a single score. His broader preparation included altitude exposure, recovery monitoring and carefully structured training blocks.

“Everyone’s getting so much faster every year, and the way that I get fast is stacking,” Kerr said. “I’m stacking years, I’m stacking days, I’m stacking months.”

What Comes Next

The record is the latest milestone in Kerr’s career as he prepares for the newly revived Commonwealth Mile at the Glasgow 2026 Commonwealth Games and the World Athletics Ultimate Championship in Budapest.

“Josh’s performance is a powerful example of what happens when world-class talent is supported by disciplined preparation, trusted coaching and meaningful data,” said Sara Webster Wylie, Vice President of Marketing at Amazfit. “We’re proud that Amazfit helped Josh and his team better understand his training, recovery and race-day effort as he pursued one of the most ambitious records in the sport.”