How Josh Kerr Trains (and How He Finally Broke the Mile World Record)

For 27 years the mile world record didn't move. Hicham El Guerrouj ran 3:43.13 in 1999 and it sat there while an entire generation of milers came and went. On 18 July 2026, at the London Diamond League, Josh Kerr ran 3:42.66 and it was gone. He'd been open about the target for a year, calling it Project 222, after the number of seconds a 3:42 mile takes. The same night he also broke the British 1500m record with a 3:27.62 split. This is the story of how a runner builds toward a number like that, and what a record mile actually tells you about your own training.

Project 222, and why the mile is a pacing problem

A mile is four laps. To run 3:42.66 you average about 55.7 seconds per lap, four times, with no lap you're allowed to lose. That's the thing about the mile as an event: it's long enough that a big aerobic engine decides it, but short enough that a single slow or panicked lap ends the record attempt. Kerr's Project 222 was as much a pacing project as a fitness one, hitting an even, ruthless rhythm rather than racing the early laps on adrenaline and paying for it at the bell.

That's the transferable idea, and it scales all the way down. Whether you're chasing a five-minute mile or a sub-20 5k, the mistake is nearly always the same: going out too hard and dying, rather than holding a pace you can actually sustain to the line. Even pacing is how records fall and how amateur PBs happen.

One engine, seen across the table

Kerr isn't a pure miler. His range runs from a 1:44 800m up through a 3:42 mile to a 13:23 5000m, and he's a world and Olympic medallist at 1500m and a two-time world indoor 3000m champion. That range is the tell: the mile, the 1500 and the 5000 are all powered by the same aerobic engine, expressed at different speeds. A 3:42 mile and a 13:23 5000 are two readings off one instrument.

This is exactly what VDOT is built to show. Feed in one race result and it derives a single fitness number, then projects your equivalent times and, more usefully, your correct training paces across every distance:

Put in your own recent race and it tells you what your engine is worth everywhere else. Kerr is what the very top of that table looks like. The value for you is the same idea at your level: your mile speed and your 5k fitness are the same base, so a result at one distance sets honest training paces at all of them, and stops you guessing.

His indoor mile, incidentally, sits just ahead of Cole Hocker's American record, and his career-long duel is with Jakob Ingebrigtsen, whom he beat at the 2023 World Championships and in the "Mile of the Century" at Eugene. Three of the fastest milers alive, three different training systems, one shared requirement: a huge aerobic base under a sharp finish.

The training behind it

Kerr is coached by Danny Mackey and trains with the Brooks Beasts Track Club, splitting time between Seattle and altitude in Albuquerque. Like every middle-distance program that works, the shape is a large aerobic base of easy mileage, a smaller amount of very fast, race-specific work to build the top end, and altitude blocks to lift the aerobic ceiling. The record didn't come from a secret session. It came from years of that base plus a deliberately engineered, evenly paced attempt on a fast night with pacemakers doing their job.

There's a lesson in the patience, too. Kerr didn't arrive as a teenage phenomenon who broke the record at 21. He built through a World title in 2023, an Olympic silver in 2024, world indoor golds, and a calf injury at the 2025 World Championships, and broke the record at 28. Middle-distance running rewards the long game.

What you can actually steal from it

• Pace even, not brave. A mile or a 5k is won by holding a sustainable pace to the line, not by banking time early. Records and PBs are evenly paced.
• Treat your distances as one engine. Your mile speed and your 5k fitness are the same base. Use VDOT to turn one result into training paces across the board.
• Build the base, sharpen the end. A finish like Kerr's sits on top of a big aerobic engine, most of it built by easy mileage.
• Play the long game. He broke a 27-year record at 28, after years of championship racing. Middle distance rewards patience, not shortcuts.

The mile record standing for 27 years made it feel permanent. It wasn't. It fell to a runner who built a huge engine, picked a number, and paced it perfectly. You won't run 3:42, but the method under it, base, sharpen, and pace it honestly, is the same one that lowers your own times.

More in this series: Cole Hocker, Jakob Ingebrigtsen, Eliud Kipchoge and Courtney Dauwalter.

Sources

Kerr's mile world record (3:42.66, 18 July 2026, London Diamond League), his Project 222 framing, the British 1500m record set the same night, his personal bests, titles, coaching setup with Danny Mackey and the Brooks Beasts, and his rivalry with Jakob Ingebrigtsen are recorded on his Wikipedia profile. The previous record, El Guerrouj's 3:43.13 from 1999, and the 27-year gap are documented in the mile world record progression. Specific training-session detail is limited in the public record, so this piece describes the general structure of elite middle-distance training rather than a precise weekly plan.

Cover photo by Andrewnward, CC BY-SA 4.0, via Wikimedia Commons.