Josh Kerr's 3:42.66 mile record is now official, ratified by World Athletics. Kerr broke the long-standing record set by Hicham El Guerrouj in 1999. His performance at the London Athletics Meet on July 18 was historic.

Alongside Kerr, three other records were ratified. Yomif Kejelcha reclaimed the men's half-marathon record in Buenos Aires. Alison dos Santos improved the men's 400m hurdles record in Zurich. Masai Russell set a new women's 100m hurdles record. Read more racing coverage.

Kerr's mile record was the first to be ratified. His splits were impressive, with a 1,500m split faster than his British record. Kejelcha's half-marathon time was 29 seconds faster than the previous record. Dos Santos and Russell's records were set at the same event. Related: Josh Kerr Carries Match Ball for Scotland vs. New Zealand.

This original Runner World brief is based on reporting from Canadian Running. Visit the source for its complete reporting, context and any later corrections.