Chiltern Hills 100K Ultramarathon

The Chiltern Hills 100K Ultra Marathon

If you're searching for a classic 100k ultra marathon on some of the South East's most cherished trails, the Chiltern Hills 100K Ultra is a formidable and rewarding challenge. This event is a proper test: a full, anti-clockwise loop that starts and finishes in Chesham, taking you on a grand tour of the very best the Chilterns have to offer.

It's a fantastic race for anyone wanting to conquer the 100K distance and is also a 100K UTMB Index Race, making it a perfect qualifier for bigger mountain goals.

Course

The Chiltern Hills 100K Ultra is a single, continuous 100km loop, which many runners prefer for its sense of an epic, unbroken journey. From the start at the event base in Chesham, you'll head out on an anti-clockwise adventure.

This course is a showcase of the area's biggest landmarks. You'll be treated to stunning sections of the Ashridge Estate, climb the iconic Ivinghoe Beacon (part of the Ridgeway National Trail), and tackle other famous viewpoints like Coombe Hill and Whiteleaf Hill.

With 1,800m of elevation spread over the 100km distance, this is a course that demands some hill training. It’s relentlessly undulating, a classic "death by a thousand cuts" challenge rather than one or two monster climbs. The terrain is fantastic, mixing runnable woodland trails, open chalky ridges and well-maintained national paths.

The route is fully marked with arrows and ribbons, but self-sufficiency is key. All runners are also required to carry a GPS track on their watch or phone. You'll be well looked after, with six fully-stocked aid stations along the route, offering a wide range of ultra fuel, and there's a drop-bag facility at the Hastoe checkpoint (around 41km), which is perfectly placed for grabbing your specific nutrition or a change of kit.

If you like the sound of the Chiltern Hills 100K Ultra, please visit their official race website for the most up-to-date details and info.