Three days before Jacob Kiplimo runs his first ever marathon, the only people in London seemingly not talking about a sub-two-hour clocking are Jacob Kiplimo and his coach. The Ugandan arrived in the capital on Monday on the back of a winter that has seen him break the world half marathon record twice — first to 56:42 in Barcelona in February, then extending to 56:39 at a private time trial in Uganda last month — and a buildup his Italian-based technical team describes simply as "the most consistent of his career". Every credible betting market in the sport now prices him as the favourite for Sunday, ahead of defending champion Sabastian Sawe, and the sub-2:00 question that has been dormant since Kelvin Kiptum's death in 2024 is back on every marathon podcast.
The numbers are genuinely unusual. Kiplimo's coach Peter Chelangat, working in conjunction with the Rosa camp out of Iten, told reporters at Wednesday's London Marathon media day that the 25-year-old has been running 200 to 220 km a week for ten consecutive weeks — a jump of roughly 50 km on his standard half-marathon block. His tempo staples have included a 30-kilometre progression at 2:50-per-kilometre pace (a 2:00 marathon extrapolation) and a 40-minute threshold at an average of 2:53. Asked directly on Monday whether the world record was the target, Kiplimo smiled, shook his head, and offered only: "I want to finish the race." Chelangat, standing alongside him, was equally measured, saying the plan was "to run a time we can trust" and nothing more.
That public restraint is not simply marketing. London's course, although flat by marathon-major standards, is not a world-record track in the way Berlin and Valencia are: the early Greenwich tunnel section, the cobbles on the approach to Tower Bridge, and the tight Isle of Dogs turns collectively cost the leaders 30 to 45 seconds against an optimised pacing line. Kiptum's 2:01:25 course record from 2023 remains, in coach Renato Canova's words, "worth a minute on any other major." The men's pacers have been instructed to deliver halfway in 60:00 — 20 seconds slower than would be needed for an official sub-2:00 attempt — with the implicit brief that the record Kiplimo can realistically attack is Kiptum's course mark, not the 2:00:35 overall world record.
The supporting cast makes the race harder to read. Sawe ran 2:02:27 to win last year in the most imperial back-half ever seen on the course, and is unbeaten in a marathon. Joshua Cheptegei, Kiplimo's compatriot, arrives chasing redemption after a 2:08:59 debut in Valencia in 2023, and 2024 Olympic champion Tamirat Tola has quietly completed a 120 km week in Flagstaff that insiders are comparing to his Paris build-up. Yomif Kejelcha, the Ethiopian world indoor 3,000m record holder, also makes his marathon debut and brings Kiplimo's closest track credentials. Between them, the five fastest men on the start line have run inside 2:04 in their last four outings.
Whatever the final clock says, Sunday will reshape Kiplimo's place in the sport. If he wins, a Chicago-Berlin autumn campaign becomes inevitable and the sub-2:00 sells itself. If he splits 60:00 and fades, the question will not go away so much as shift: the idea that a modern half-marathon world-record holder cannot translate the fitness to 42.195 km is, post-Kiptum, a harder case to make than it once was. And if he actually runs something shocking — the clock reading 1:59-anything on the Mall — London will have hosted not just the fastest legal marathon in history, but the single biggest moment the distance has seen since Breaking2. No one in his camp wants to say any of that out loud. Sunday, they will not need to.