Back to a more traditional obstacle race is The Nuts Challenge.

Although their 7km event is filled with fun runners having a great time on a course packed with military obstacles and natural challenges, things get a little more serious when you approach their 28km Tough Nuts challenge in March.

In 2013 only six people finished the challenge, which even stopped the seemingly unstoppable Jonathan Albon, the UK’s leading obstacle racer, who came down with hypothermia.

He returned this year to complete with only 16 others (less than 7% of those that started), some of which spent six hours wading through water, climbing walls and slipping around in churned up clay, with little or no grip.

Sign up for the brutal Tough Nuts challenge here

Pete Rees is the founder of Mudstacle, an independent community website for mud runs, obstacle courses and endurance races. Check out his website here