Thunder Races

SEP-MAR
12-13
2026-27
A UK trail and ultra series offering fully marked, fully supported races with generous cut-offs and runnable countryside courses.
12-13 Sep-Mar 2026
UTMB 50K 81 miles 50 kilometers 25 kilometers

Always double-check with the organizer's website! This page may contain affiliate links.

Thunder Races

Thunder Races is a UK trail and ultra running series that creates welcoming, fully supported events. The series stages multiple events each year with fully marked routes and generous cut-offs so runners do not need to navigate alone.

Events feature high energy volunteers, rave stations, and an inclusive atmosphere. Courses use waymarking and support stations so runners can focus on running rather than navigation or being left alone.

The routes are set on runnable countryside terrain and mix rural paths, villages, and open country. Organisers describe the courses as mentally and physically manageable, with options that suit runners stepping up in distance as well as those new to trail running.

Event examples:

  • 25 km Harrold Odell Trail Race (13 March 2027)
  • 50 km Harrold Odell Trail Race (13 March 2027)
  • 81 miles Pilgrim's Reckoning, a circular ultra on the Bunyan Trail in Bedfordshire (12 September 2026)

Pilgrim's Reckoning is an 81 mile circular ultra following the official Bunyan Way markers throughout. The full loop is waymarked and must be completed within 24 hours, covering a mix of rural paths, villages, and open countryside. Visit the organization's website for the most recent information.

81 mi
Pilgrim's Reckoning
50 km
Harrold Odell 50km Trail Race 2027
25 km
Harrold Odell 25km Trail Race 2027

Events nearby

Three evening trail time trials in the Chilterns on 23 Sep, 21 Oct and 25 Nov 2026, each around 8 km, marked and chip timed with mandatory head torch.
A Backyard Ultra in Welwyn Garden City where runners repeat a 4.167 mile loop each hour until one remains; entry includes drink vouchers and a commemorative pint glass.
Timed multi lap event at Regatta Meadow in St Neots on a 5.3 km out and back course, offering distances from 5 km to ultra. Participants decide how many laps to run and all receive a finishers' medal.
A backyard ultra at Turvey House where runners complete a 4.167 mile (6.7 km) loop each hour; failing to start a loop on the hour means elimination. Entries include solo, paired teams alternating loops, and an 8 hour day cap.
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