Thunder Races

Flitwick, United Kingdom • 13 Mar 2027

Thunder Races

Thunder Races runs a series of trail and ultra events designed to make trail running welcoming and supportive. Events are fully marked and fully supported, with generous cut-offs, volunteers, and on-course entertainment such as rave stations. The series focuses on clear waymarking and staffed aid so participants do not need to navigate alone.

Courses use runnable paths through countryside, villages, and rural tracks. Routes are described as mentally and physically manageable and are set up to reduce navigation stress. The format aims to work for people who are new to trail running and for those stepping up to longer distances.

Notable events and dates include:

  • 81-mile Pilgrim's Reckoning, circular ultra on the Bunyan Trail, Bedfordshire (24 hours)
  • 25 km Harrold Odell Trail Race, 13 March 2027, fully marked and supported
  • 50 km Harrold Odell Trail Race, 13 March 2027, fully marked and supported

Pilgrim's Reckoning follows the official Bunyan Way markers throughout and passes a mix of rural paths, villages, and open countryside. The event descriptions emphasize runnable terrain and support infrastructure so participants can focus on pacing and finishing within the stated time limits. Visit the organization's website for the most recent information.

Race information

50 km
Harrold Odell 50km Trail Race
25 km
Harrold Odell 25km Trail Race
Visit the organization's website for the most recent information.
Trail runs nearby

A guided morning trail run of about 10 km through bluebell carpeted woods in the Chiltern Hills near Tring. Participants are grouped by ability and led by run leaders; facilities include bag storage and a nearby cafe and dogs may join with..

A guided 5 km spring trail run in the Chiltern Hills with a Movement Project session to develop mobility and trail technique, held at Church Farm Cafe in Aldbury with facilities and on-site parking.

A 100-kilometre anticlockwise loop through the Chiltern Hills, the race follows The Ridgeway and local trails with six checkpoints, marked navigation and open GPS tracking. The event is based in Chesham and limited to 250 runners.

A self-guided 13-mile run along Letchworth's scenic Greenway trail. This is a run, not a race, due to road crossings. Finishers get a wooden medal and refreshments, with profits supporting a local youth mental health charity.

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