Four days out from the 46th TCS London Marathon, the story has moved from who is on the start line to what they might do once the gun fires. The elite press conferences at the Tower Hotel on Friday and the expo at ExCeL that opened on Wednesday morning have given the final shape to a race whose narratives have been gathering for months. Sebastian Sawe and Tigst Assefa return as defending champions; Hellen Obiri and Joshua Cheptegei make their London debuts; weather forecasts point to dry, cool running conditions throughout; and a mass field of 59,000 — the biggest in the event's history — will follow the professionals off the Blackheath start lines. With bib collection under way, here are the seven storylines Running Lookout is watching.
The first is the women's field, which is already being called the most competitive in marathon history. Four athletes — Assefa (2:11:53), Hassan (2:13:44), Jepchirchir (2:13:44) and Joyciline Jepkosgei (2:14:00) — have sub-2:15 personal bests, and a fifth, Kenya's Hellen Obiri, will chase that barrier in her first non-Boston, non-New York major. Race director Hugh Brasher confirmed on Monday that the pacemaking will target 67:30 for the opening half, a split that would put the leading group on 2:15:00 pace, inside Paula Radcliffe's 2:15:25 course record and almost exactly on Assefa's women's-only world record of 2:11:53. The second question, however, is whether Olympic champion Sifan Hassan will be there. Hassan withdrew in late March citing an Achilles problem; Athletics Weekly reported last week that her late decision to re-enter came after an unusually quick recovery, though she was photographed in a protective boot as recently as 7 April. Her race-sharpness is the biggest known unknown in the women's race.
The third storyline is the men's course record. Sawe, who won in 2:02:27 last year, told reporters on Monday that the winner will probably have to break Kelvin Kiptum's 2:01:25 standard set in 2023. Kiplimo, who finished second on his debut in 2:03:37 in 2025 before improving to 2:02:23 at Chicago in October, is the obvious contender, as are Ethiopia's Tamirat Tola (Olympic bronze medallist) and world indoor mile record-holder Yomif Kejelcha, who makes his marathon debut alongside Cheptegei. London Marathon Events has briefed that lead pacemakers will target 60:40 at halfway; anything slower and the course record is probably safe, anything faster and the men's race is set up for a potential 2:00 barrier assault. The fourth storyline follows on from the third: the super-shoe landscape. Sawe races in the adidas Adizero Adios Pro Evo 2, Kiplimo and Cheptegei in the same model under Uganda's federation-wide deal, Kejelcha in the Nike Alphafly 4, and Tola in the new Asics Metaspeed Ray. There has never been more variety at the sharp end of a major.
The fifth storyline is British, and it has two parts. The men's race has seen an unhappy spring of withdrawals — Emile Cairess, the holder of the British course best, pulled out on 31 March with a calf injury, and Mahamed Mahamed is still short of fitness after a February hamstring tear — leaving Phil Sesemann and newcomer Jack Rowe to carry the home hopes alongside debutant Hugo Milner. The women's field, by contrast, has been building for 12 months. Eilish McColgan, who finished eighth last year, returns in significantly better condition; Rose Harvey, Calli Thackery and Philippa Bowden are all on sub-2:23 form; and Birmingham-based Sam Harrison will make the marathon debut her 2:22:38 half-marathon mark promised. Running Lookout understands there is a realistic chance of five British women going under 2:25 on Sunday, which would equal the all-time national record in a single race. The sixth storyline is the wheelchair race, where Swiss pair Marcel Hug and Catherine Debrunner are looking to double up after winning at Boston on Monday; Hug clocked 1:16:05 on the notoriously tough Boston course and will be fresh for Sunday, while Debrunner, the women's world-record holder, targets the first sub-1:34 London on a course that historically produces quick times.
The seventh and final storyline is the mass race itself. A record 59,000 entrants, the product of last April's million-strong ballot, will set off from Blackheath from 09:30 on Sunday. Transport for London has announced an enhanced 10 per cent service uplift on Jubilee, Northern, DLR and Elizabeth line routes to handle demand, the event's charity fundraising is projected to exceed £73 million (pushing cumulative lifetime total past £1.4 billion), and nearly 1,000 street parties are registered along the route — a new record. Celebrity entries of note include Jamie Dornan, Harry Judd, four-time F1 champion Sebastian Vettel, swimmer Tom Dean, recently-retired NASA astronaut Sunita Williams (just 12 days after she finished Boston) and Strictly-winner Rose Ayling-Ellis. Sunday, in other words, is a race with something running within it for almost every audience. Four days — and most of a record expo weekend — stand between ExCeL and the starting line at Blackheath.