What is it? Tough Mudder, Judgement Day, Survival Of The Fittest – all cross-country races between six and 12 miles, interspersed with obstacles, completed in teams.

How much does it cost? It varies. A small, local event might charge £20, but, ludicrously, expect to pay over £100 to enter a Tough Mudder.

What does it promise? Invariably, according to the race’s publicity material, “the toughest race in the world”. It actually depends how seriously you take it. It’s either the end point of months and months of arduous training, or an excuse to get loads of photos of you sliding around in the mud in a tutu.

What’s it actually like? If you train properly, a lot of fun – if your kind of fun involves jumping fences, crawling under barbed wire, wading through rivers and carrying tyres. But injuries are common – one friend was left with mild hypothermia. You’re bound to end each race with a litany of scratches and bruises; and perhaps a wild, traumatised look in your eye. Since you’re running in a team, however, the sense of camaraderie should push you through. If you’re more of a straight runner, try something like Judgement Day, where most of the obstacles are clumped together at the end of the course. If not, the Nuts Challenge is much more densely packed.

Best and worst bit The best bit is always the feeling of elation when you cross the finish line. Worst bit? Paying through the nose to be mildly electrocuted, then realising that parking your car and using the bag drop costs extra.

Is it worth it? If you pick your event carefully, definitely.