The XNRG Chiltern Challenge Ultra, 19th July 2025.
Take part in one of our most popular fundraising events of the year, The Chiltern Challenge Ultra Marathon.
Set in a spectacular Area of Natural Beauty you can run or walk the full 50km ultra marathon, a 25km half ultra or the full ultra as a team of up to 5 people.
You’ll traverse well marked trails and footpaths taking in beautiful scenery while being cheered on by a fantastic crew providing you with support and snacks all the way.
This popular race, known for its great atmosphere, is especially good for those looking for a supportive event for their first ultra within easy reach of London.
XNRG, who host the event ensure everything is taken care of at the Chiltern Challenge so you can focus on the experience, this includes free transfers from the station, free parking, free photos, changing facilities and heaps of tea and cake!
Most importantly by taking part you’ll be funding life saving and life changing surgery for children in Uganda as your entrance fee helps fund our work to give children the safe surgery they need.
We also offer an option to race for FREE by fundraising to cover the cost of an entire operation. Once you’ve signed up to take part just set up your fundraiser profile on our website and share the link to family and friends so they can donate to your page.
Our partnership with XNRG has funded hundreds of operations over the years from neurosurgery to skin grafts as well as thousands of eye tests as part of our Glasses for Classes programme. Visit our Success Stories page to find out about some of the children whose life changing operations have been funded by these XNRG events.
To register to take part and for more details including start times and route please visit XNRG.
See you at the start line 🏃♀️🏃♂️
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