Yomif Kejelcha has taken the half marathon into new territory. Racing the Media Maratón Ciudad de Buenos Aires on 23 August, the Ethiopian stopped the clock at 56:51 to become the first man to break 57 minutes for the distance, removing 29 seconds from the world record of 57:20 that Uganda's Jacob Kiplimo set in Lisbon in March. It is the largest single improvement to the men's record in years, and it returns the mark to the athlete who held it before Kiplimo's Lisbon run.
The scale of the performance bears repeating. Kejelcha averaged well inside 2:42 per kilometre for 21.1km, a pace that would have won most elite 10km road races not long ago — sustained for more than twice the distance. The Buenos Aires course, flat and run in cool Southern Hemisphere winter conditions, has quietly built a reputation as one of the fastest in the world, and the Argentine capital now holds the fastest half marathon ever recorded.
The record continues a remarkable season for the 29-year-old. Kejelcha made his marathon debut in London in April, finishing second in 1:59:41 in the race in which Sabastian Sawe broke the two-hour barrier — a debut faster than any marathon run before this year. He has spoken openly since of his belief that he too can break two hours, and Sunday's run in Buenos Aires will only harden that conviction.
It also sharpens the rivalry that is coming to define men's distance road running. Kiplimo and Kejelcha have now traded the half marathon record twice in six months, with each iteration lowering the mark substantially. Both men are expected to target major marathons over the next year, and the prospect of the two meeting over 42.2km — with Sawe, injury permitting, completing the field — is the most tantalising in the sport.
World Athletics must still complete its standard ratification process, including doping control paperwork and course verification, before 56:51 enters the record books formally. No obstacle is anticipated. What is already beyond dispute is the trajectory: the half marathon record has fallen by nearly a minute inside two years, and the men chasing it are increasingly treating it as a stepping stone to the marathon's ultimate prize.