The Rasselbock 545 will return to Horspath Athletics Track in Oxford on 25 July 2026, promising one of the most challenging endurance events in the UK. Following this year’s Rasselbock 505, where Alex Marshal smashed through the existing record, organisers have set a new target that gives the event its updated name.

Organisers say: "To claim the £100 cash prize next year, runners will need to complete an incredible 545 laps of the track within either the 24 hour race or the first half of the 48 hour event. The lap distance might be a modest 400 metres, but the sheer repetition demands a rare blend of stamina, resilience and mental fortitude."

Those chasing the record will be pushing themselves to the limit, but the event also welcomes runners looking to take on their own personal challenges. Participants can choose from six, 12, 24 or 48 hour formats, with the extended 48 hour option making this the only known event of its kind in the country. Organisers are also working towards gaining official recognition for the race, which would be a notable milestone for UK endurance running.

The atmosphere at Horspath has become a hallmark of Rasselbock Running’s events, with a mix of competition, camaraderie and good humour keeping spirits high as the hours roll on. Whether it’s your first time running on a track or you’re an experienced ultra athlete, there is something compelling about the shared challenge and the steady rhythm of lap after lap.

Supporters line the track to cheer on runners, adding to the festival-like feel, and the event encourages people to stay and soak up the experience as both a participant and a spectator. The tight-knit setting means you’re never far from encouragement or a friendly face, even in the small hours of the night.

If you'd like to know more, visit the Rasselbock Running website.

Image: Derrick/The Running Photo Guy