The Northumbrian
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The Northumbrian
The Northumbrian is an endurance event set in the waters, forests and terrain of Northumberland and Kielder. It is open to a limited number of individuals and teams. On 28 June 2026 the event will mark the fifth anniversary of the full and half iron distance triathlons.
The programme combines swim, bike and run stages around Kielder Water and Forest. Swim stages take place in Kielder Water, the bike routes pass through the valley and across the Border, and the run stages follow forest trails that host the Kielder Marathon.
Distances include:
- Full and half iron triathlons: Swim 2.4/1.2 miles, Bike 112/56 miles, Run 26.2/13.1 miles
- 50K Ultra Trail Run: 48 km with +700 m elevation
- 20K Trail Run: 27 km with +400 m elevation
The event will host the 2026 British and English Middle Distance Triathlon Championships; all entries in the half iron distance triathlon will automatically be entered into the championships.
Entry fees include The Northumbrian cycling jersey or running T-shirt for individual entries, a swim cap for triathlon entrants, electronic chip timing, on-course support and nutrition, a medal and finisher's goody bag, and parking. Visit the organization's website for the most recent information.
