Chiltern Hills 100K

Overview

The Chiltern Hills 100K is a 100K trail ultramarathon with 1800m+ of elevation, next held on 9 May 2026. The event is based at Chesham Guides Headquarters in Lowndes Park, Chesham (HP5 1HX). The race is TRA licensed, is a UTMB World Series index race, and permits a maximum of 250 runners. Minimum age for entry is 20. Registration fee is £152 (£150 for affiliated runners) and entries close on 22 April 2026.

Route, checkpoints and logistics

The route follows an anticlockwise loop through the Chiltern Hills and passes landmarks including Ashridge Estate, Coombe Hill, Whiteleaf, Bledlow Ridge, Great Hampden and Great Missenden. The course is marked and open GPS tracking is provided. There are six checkpoints with toilet facilities at approximately 14K, 28K, 41.4K, 57.8K, 75.3K and 88K. Checkpoints provide water, cola, electrolyte drink, gels, chews, crisps, pre-made sandwiches, flapjacks, fresh fruit and hot drinks at selected locations. A drop bag service is available at Hastoe (41.4K). Chip timing, live results and medical support are provided. Runners must carry required kit for the whole race, including a mobile phone, GPX route on a device, at least 0.5L hydration, waterproof or windproof jacket, additional warm layers and leg cover, head torch with spare battery, basic first aid items, reusable cup and cash or card. Post-race food and a finisher medal are included. Visit the organization's website for the most recent information.