The UK's Most award winning muddy obstacle course
Escape the everyday and get stuck into our award-winning muddy obstacle course at Nuclear Races, Essex’s best mud run. From thrilling slip and slides and the iconic Travelator to mud pits and cargo nets, every obstacle delivers mud, fun and a genuine sense of achievement. Whether you’re a complete beginner, seasoned racer, adult or child, there’s a race for everyone
Nuclear RUSH
- Various Distances
- 4 Years +
Prepare for the ultimate muddy obstacle course race at Nuclear Rush. With 6K or 12K courses, there are over 70 obstacles on the 12K course, including our famous Death Slides and para-plunge zip lines. Designed to test every fitness level, whether you’re a beginner or a seasoned mud racer, this is a must-do event!
Nuclear FALLOUT
- Various Distances
- 14 Years +
Tackle the Nuclear winter beast! Choose from our multi award winning 6K or 12k course. Whether you’re a newbie, small group, big team, veteran or competitive obstacle racer, Nuclear courses are thoughtfully designed to be challenging, fun and achievable for all ages and every fitness ability.
BRITISH OCR CHAMPIONSHIP
- 12K
- 16 Years +
The competitive part of our Nuclear Rush event, we’re proud to hold the British OCR Championship here annually. Supported by British Obstacle Sports and designed for elite and pro OCR athletes, challenge yourself to over 60 obstacles – some of which are mandatory – to be recognised as a top performer in OCR.Â
9th May 2026
Nuclear Offers
Award winning
Award‑winning obstacles on a permanent course, in a farmland setting including mud, woods, rivers and lakes.
Signature obstacles
Iconic signature obstacles, including the 20‑foot Deathslide, Travelator and a 15‑lane zip‑wire into water.
Races for all
A range of races which are inclusive of all fitness levels, abilities and ages.
Group and team friendly
Perfect for groups and teams to participate together and also offers the perfect opportunity for raising money for charity.
Event village
Friends or family can watch the race, enjoy music, food, drinks and merch in our spectator friendly event village while the action happens nearby.
Varied courses
Varied distances and formats including beginner friendly options.
In my opinion Nuclear Races is the most fun of all the OCR franchises I have entered so far,
The obstacles are numerous, varied and challenging enough to be interesting without being overly difficult, there is a very good level of decent quality mud even without pre event rainfall which I love, everyone who works there was friendly and helpful from the on course marshals to those in charge and were willing to go the extra mile to make my experience as enjoyable as possible, I fully recommend all Nuclear Races events to any OCR fan and it will defiantly be somewhere i hope to visit many times in the future
Gary Judd
This is my 3rd Family Wave run at Nuclear Races and it is the best event!
The course is challenging but loads of fun, the whole event is brilliantly well organised and the marshals around the course are so supportive and encouraging giving you loads of confidence and making sure it is all super safe, particularly the water obstacles. It is a must in our family diary every year!Â
Sophie Mather
See you there! #LoveMud
Yet another amazing day at Nuclear Races on Sunday, with 8.5 hours of fun in the mud and obstacles for Nuclear Oblivion.
Nuclear really does have it all: a huge range of quality obstacles ranging from silly fun to serious rigs, varied terrain, lots of water and more types of mud than you can imagine. Take a look at the videos and you’ll see what I mean – the Deathslide, in particular, is an absolute blast!
Great obstacles are only part of their success, though. The organisation and facilities are first rate, from the smooth parking and registration, excellent bag drop and robust changing tents to the warm washdown showers (which are always welcome at the end of a race)! The heart of the event, though, is the staff and marshals who are always amazing and make it so much more than just a run – they are incredibly supportive, friendly, helpful and always encouraging.
All in all, Nuclear is an absolute must for anybody interested in OCR – from first timers to competitive athletes, from young kids to adults, from solo runners to families and friends – and it deserves far more than five stars. Give it a go – you won’t regret it!
Chris Jones
It made a brilliant day
Big thanks to the staff and volunteers that made the day brilliant. Super friendly and chatty marshals, with one going out if their way to help me find my husband (who had gone off on a second lap), and the car park marshal remembering me and my daughter and allowed us to park closer to collect said husband. Great vibes, family friendly and the some of the best staff and volunteers I’ve come across at events like this!
Anonymous
How to find us
Nuclear Races is located in Brentwood, Essex just 15 minutes from the A12, M25 and M11.
By Train and taxi, we’re just 15 minutes from Brentwood station (on the mainline from Liverpool St) or 15 minutes from Epping Underground station.