How Josh Kerr Trains (and How He Finally Broke the Mile World Record)
Josh Kerr ran 3:42.66 on 18 July 2026 and ended a 27-year-old mile world record. The training and pacing behind Project 222.
Hicham El Guerrouj ran 3:43.13 in 1999 and the mile world record sat there for 27 years. On 18 July 2026, at the London Diamond League, Josh Kerr ran 3:42.66. He had called the target Project 222 for a year, after the number of seconds a 3:42 mile takes. The same night he broke the British 1500m record with a 3:27.62 split.
Project 222, and why the mile is a pacing problem
A 3:42.66 mile is four laps at about 55.7 seconds each, with no lap you can afford to lose. The event is long enough that the aerobic engine decides it and short enough that one panicked lap ends the attempt. Project 222 was a pacing project as much as a fitness one: an even, ruthless rhythm instead of racing the early laps on adrenaline.
That scales down. Whether you chase a five-minute mile or a sub-20 5k, the usual mistake is going out too hard and dying. Records and PBs are evenly paced.
One engine, seen across the table
Kerr is not a pure miler. His range runs from a 1:44 800m through a 3:42 mile to a 13:23 5000m, plus world and Olympic 1500m medals and two world indoor 3000m titles. The mile, the 1500 and the 5000 are one aerobic engine expressed at different speeds.
VDOT shows exactly that. Feed in one race result and it derives a single fitness number, then projects your equivalent times and training paces across every distance:
VDOT
49.8
Danielsin juoksukuntopisteytys
| Alue | Vaihteluväli | Mitä se kehittää |
|---|---|---|
| E | Kevyt / pitkä 4:54–5:53 /km | Aerobinen perusta, hiussuonet, rasva-aineenvaihdunta; suurin osa viikkovolyymista. RPE 3–4, keskusteluvauhti. |
| M | Maraton 4:26–4:51 /km | Maratonspesifi kestävyys ja taloudellisuus. RPE 5–6, tasainen. |
| T | Kynnys 4:16–4:28 /km | Laktaattikynnys; mukavan kova vauhtikestävyys ja cruise-intervallit. RPE 7, ~1 h kilpailuvauhti. |
| I | Intervalli 3:51–4:01 /km | VO₂max; 3–5 min kovat vedot. RPE 9, kova. |
| R | Toistot 3:19–3:42 /km | Nopeus, taloudellisuus ja juoksuteho; lyhyet nopeat vedot täydellä palautuksella. RPE 9–10, nopea ja hallittu. |
E · Kevyt / pitkä. Aerobinen perusta, hiussuonet, rasva-aineenvaihdunta; suurin osa viikkovolyymista. RPE 3–4, keskusteluvauhti.
M · Maraton. Maratonspesifi kestävyys ja taloudellisuus. RPE 5–6, tasainen.
T · Kynnys. Laktaattikynnys; mukavan kova vauhtikestävyys ja cruise-intervallit. RPE 7, ~1 h kilpailuvauhti.
I · Intervalli. VO₂max; 3–5 min kovat vedot. RPE 9, kova.
R · Toistot. Nopeus, taloudellisuus ja juoksuteho; lyhyet nopeat vedot täydellä palautuksella. RPE 9–10, nopea ja hallittu.
- VDOT-arvosi 49.8 on yksittäinen luku, joka kuvaa nykyistä juoksukuntoasi ('VO₂max', joka on korjattu juoksun taloudellisuudella). Jokainen harjoitusvauhti johdetaan siitä.
- VDOT lasketaan yhdestä tuoreesta, kovasta kilpailusta tai aika-ajosta. Käytä tulosta, jonka juoksit täysillä, mieluiten 5 km tai pidempi; puolimaraton tai 10 km antaa vakaimman arvion.
- Vaihda yksikkövalitsimella lukeaksesi vauhdit mailia kohden. Kun kuntosi paranee, juokse uusi kilpailu; VDOT ja kaikki vauhdit päivittyvät.
- Nämä ovat Danielsin erilliset harjoitusvauhdit (E, M, T, I, R), eivät yhtenäiset vyöhykkeet: juokset kutakin vauhtia tiettyä tarkoitusta varten. Kovempien vauhtien (T, I ja R) väliset aukot ovat tarkoituksellisia, eivät virhe.
PDF tuloksillasi, plus QR-koodi niiden avaamiseen uudelleen milloin tahansa.
Kerr is the top of that table. At your level the idea is identical: one result sets training paces at every distance.
His indoor mile 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 training systems, one shared requirement: a huge aerobic base under a sharp finish.
The training behind it
Kerr is coached by Danny Mackey with the Brooks Beasts Track Club, splitting time between Seattle and altitude in Albuquerque. The shape is standard for middle distance that works: a large base of easy mileage, a smaller amount of very fast race-specific work, and altitude blocks to lift the aerobic ceiling. The record came from years of that base plus an evenly paced attempt on a fast night with pacemakers doing their job.
He was not a teenage phenomenon. He built through a World title in 2023, Olympic silver in 2024, world indoor golds and a calf injury at the 2025 World Championships, and broke the record at 28.
What you can steal from it
- Pace even. A mile or a 5k is won by holding a sustainable pace to the line, not by banking time early.
- Treat your distances as one engine. 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 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.
More in this series: Cole Hocker, Jakob Ingebrigtsen, Eliud Kipchoge and Courtney Dauwalter.
Sources
Cover photo by Andrewnward, CC BY-SA 4.0, via Wikimedia Commons.
