The Northumbrian
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Overview
The Northumbrian is a multi-discipline endurance event held at Kielder Waterside in Kielder Water and Forest Park, Northumberland. The 2026 edition is the fifth running of the event and includes the British and English Middle Distance Triathlon Championships. The event features triathlon, team relay and ultra trail-run formats, and the 2025 edition attracted over 400 athletes.
Distances and course
- Full Iron Distance Triathlon - Swim 2.4 miles, Bike 112 miles, Run 26.2 miles
- Half Iron Distance Triathlon - Swim 1.2 miles, Bike 56 miles, Run 13.1 miles
- Team Full & Half Iron Distance - relay of the full or half distances
- 50K Ultra Trail Run - 48 km, +700 m elevation (UTMB index)
- 20K Trail Run - 27 km, +400 m elevation (UTMB index)
The swim takes place in Kielder Water. Cycling follows local valley and border roads. Running uses forest trails and paths in Kielder Forest.
Entry details and included services
Early bird pricing is available until 31 October 2025 for the listed events. Race entries include a cycling jersey or running t-shirt for individual entries, a swim cap (triathlon), electronic chip timing, on-course support and nutrition, a medal and finisher goody bag, and parking. Some triathlon distances have specified cut-off times and age or licensing restrictions apply for triathlon entrants. Visit the organization's website for the most recent information.