No. of days 1 day
Distance 31 / 16 mi
Ascent gain 695 / 328 m
A one-day, 50km ultra raising funds for a great cause. Choose to pay for your place upfront, or bag a FREE spot if you commit to fundraise. All funds will go to Humanity Direct, a charity changing the lives of children needing medical care in developing countries.
New this year you have the option of the full 50km ultra marathon, a 25km half ultra or complete the full ultra as part of a team of up to 5 people!
If you choose to take part as a team you will be given one race number and timing chip that your team will need to get from the start to the finish. It's up to you which part of the course each team member will cover (each person can run more than one leg) but note that you can only hand over at the standard ultra checkpoints and also that it is your responsibility to transport your team members to their handover points.
You will enter on behalf of your team and we'll ask you for the names and other basic information of your fellow team members. You can make changes to your team up until close to the event. Our usual cancellation/deferral rules apply but requesting either will be on behalf of your entire team.
We are delighted to support SheRACES and commit to providing a great experience for female participants. Find out more
- Free parking at Dr Challoner's Grammar School
- A fully recced and marked route to make the event special and challenging for all
- Full medical cover throughout
- Toilets, showers and changing facilities
- Checkpoint food and water throughout
- Free tea, coffee and cake at the finish
- Prizes and trophies for overall and category winners
- A great atmosphere and a fun, but challenging, day out
- Action photos, free to download after the event
- A quality finisher's medal
Starting and finishing at Dr Challoner's Grammar School, Amersham, the route takes in many areas of natural beauty, including the Misbourne Valley and the Chess Valley - some of the best spots in the Chiltern Hills. The route mainly follows footpaths and bridleways, with a little road section, all marked comprehensively with tape, paint and direction arrows.
We recommend you familiarise yourself with the route before the start of the race and download the GPX file or OS Maps route onto your watch or phone.
Showing route for:
Ultra start time for walkers
Ultra start time for those mostly walking, with some running
Ultra start time for runners, with some walking
Ultra start time for runners (sub 6 hours)
Half ultra mass start
Massage and refreshments available
Prize giving or when enough runners have finished
Entry for ultra
Entry for half ultra
Entry for team
The entry fee will be donated to fund a vital operation, or alternatively enter for FREE, if you commit to raise funds for Humanity Direct.
Please note: a 2.5% service charge, levied by the registration software, will be added to your total. We are using a new entry system that takes payment through the secure system Stripe. No payment information is retained by Extreme Energy, or our entry system tool.
Email us on email@example.com if you have any questions about your options.
If for some reason you are not able to make the event you have entered. The XNRG refund policy is that we will give you 70% refund of your entry fee up to 1 month before the start date of the event. You also have the option (1 month before the date of the event) to get a 100% transfer credit to another one of the other Humanity Direct 1 day events, or you can donate your entry fee to the charity. All entry fee money goes directly to the charity and directly to helping children with life changing operations. These options you can execute on your Ultrabritain entry page.
After this time we are sorry there will be no refunds or transfers to future events. Refunds will be to your booking credit card.
The only compulsory kit is a fully charged mobile phone and a minimum 500ml of water, but it's worth taking a look at our recommended kit list.
Other equipment may be made compulsory by the race director depending on the weather.
The event is supported by our course manager and his experienced on-course crew to ensure you have a great event. A fully qualified medical crew will also be there to give first aid and manage any serious medical problems in cooperation with the emergency services. We strongly recommend taking a moment to read our medical page before booking.
We've answered a range of common questions in our FAQ. For other questions, say hello on firstname.lastname@example.org.
Trains to Amersham leave London Marylebone roughly every half hour, taking 30-40 minutes. It's also on the Metropolitan London Underground line. It's then a five minute walk from the station to the school.
Amersham is roughly 15 minutes on the A335 from Junction 2 of the M40.
Join us for the first in our XNRG charity single-day series for 2024. Within a stone's throw of London, you'll race across the glorious Chilterns - all fully supported and with bags of XNRG encouragement and atmosphere. It's ideal for anyone wanting to 'step up' to covering an ultra distance, as well as being great training for multi-stage events. And it's all for a good cause.
how it works
It's simple. The entry fee is donated to Humanity Direct, OR, if you prefer, you can enter for FREE and start a fundraising page instead to raise as much as you can (minimum donation: £65/£95 for teams). 100% of donations go towards children's operations and medical care in developing countries through Humanity Direct.
You can also opt-in to receive a quality finisher's t-shirt for an extra £5.
Why we do it
In 2019, Humanity Direct raised £24,000 through the three XNRG Humanity Direct Ultras, funding life-saving and life-changing operations for 35 children. We're hoping to raise even more in 2024!
- Nick Swift, Humanity Direct’s Founder
Entries will close one week before the event (or when full). A waitlist option will be available if the event becomes fully booked.
Navigation and Support
The event is supported by our course manager and his experienced on-course crew to ensure you have a great event. A fully qualified medical crew will also be there to give first aid and manage any serious medical problems in cooperation with the emergency services.
Due to the risk of cross-contamination, we can't provide checkpoint food to suit all dietary requirements. If you require special food or snacks to suit any allergies or vegetarian/vegan diets, please bring your own. Put them in containers, marked with your name and checkpoint number and give them to the checkpoint teams at the start of the race.
Event T-shirts are no longer included in the cost. The cost of T-shirts goes to Trees not Tees and a tree will be planted instead. You have the option of purchasing a T-shirt when entering the event, if you'd like one.
For more details visit their website - https://treesnottees.com/
A big thank you to everyone at XNRG and Humanity direct for a wonderful day yesterday, you even sorted the weather!! It was a beautiful route and really well organised and signed. Thanks to all the volunteers and everyone who made it possible.
I just wanted to say how much I enjoyed my first ultra on Saturday! Wasn’t quite prepared for the mud... but at least the weather was lovely! I particularly enjoyed how kind and supportive everybody was, and the great spirit everybody had throughout the whole day.
A big thank you for another great event.
Great organising, great support, fab checkpoints with picnics, love the course (if a bit muddy).
I love the atmosphere of your events, both the participants, crew and supporters.