London’s longest run DONE, join us in 2026!
London’s first ever 100k Ultramarathon, the London 100, ran on Saturday 10th May, 2025. Billed as ‘London’s longest ultra run’, with 3 challenge distances (100km, 50km, and 25km), the event attracted a wide range of participants from experienced ultramarathoners to those stepping up from marathons or half marathons.
From a superb indoor Central London run HQ, four 25km routes explored north, south, east and west of the capital in a ‘clover leaf’ route design. The route took runners past over 100 famous sights and landmarks of one of the world’s greatest cities, all in one long run.
London 100 was co-created by Camino Ultra and Participation Sport with support from The Running Consultancy. The event was created to showcase the amazing and diverse spaces London has to offer runners, to be accessible without long distance (for many) to travel to and from the event and to attract international runners to our great city.
Whether running to compete or striving to complete the course in the 17-hour cut off time, runners reported their joy at experiencing this unique event showcasing London’s green spaces, tourist highlights and buzzing urban streets. The event was widely supported by the ultramarathon community, who came out in force to manage Checkpoints, marshal and cheer on their fellow runners.
The event attracted partnerships with Exhale Coffee, Precision Fuel and Hydration, SUMS socks, Stolt Running, Usual Objections, Hylo Athletics and charity partner Aspire. Thanks must go to Westside Runnas, Legacy Races, The Lucky Saint and Stanhope plc for their assistance.
David Bone, one of the founders of Camino Ultra said “London 100 went above and beyond expectations for us. As ultramarathon runners who this year are competing in Badwater, UTMB and Spartathlon our London 100 feels like it has all the qualities that make runners want to do those events again and again. Really proud to see so many runners who had never completed more than 50KM take on the hot conditions and with the clever use of the London Angels and the brilliant Aid Station teams they were able to be amongst our Year One finishers.”’
Diccon Loy, founder of Participation Sport said “The spirit, energy and diversity of London’s ultramarathon community has always been a great inspiration for us. To witness the mutual support and camaraderie, as well as the physical achievements of the participants was a wonderful to witness, We can’t wait to repeat the experience next year, on an even larger scale.”
The event will return in May 2026 and the organisers are looking for additional partners and event supporters; interested parties should contact david.bone@caminoultra.com
Check out the Camino Ultra RIA Member profile here .