Bored with your standard 5km or 10km road race? Fancy throwing yourself down a giant slide into a river of mud along the way? Crawling through a dark tunnel half-filled with icy water? Or hauling yourself five metres up a cargo net while your arms plead with you for oxygen?

And did I mention that at the end of the race you might have a fire hose turned on you in a farm yard or take a plunge in the icy waters of a fjord, to clean off the mud which is likely to be covering you from head to toe?

Welcome to the increasingly popular world of obstacle races. If the image of a military assault course strung out over a few miles of the Irish countryside doesn't appeal, then you are not one of the thousands who have taken part in events like Runamuck, Turf Warrior or To Hell and Back in the past couple of years. Even the Minister for Transport, Tourism and Sport, Leo Varadkar, has caught the bug and was seen enjoying the mud and snow at To Hell and Back in Wicklow in February.

Spreading like wildfire
It's not just an Irish phenomenon – obstacle races with names like Tough Mudder, Warrior Dash and the Spartan Race – are spreading like wildfire in the US. According to Outside magazine, 41,000 people entered 20 events in the US in 2010 but that grew to 1.5 million entering 150 events last year generating an industry worth about $250 million (€191.4 million).

Back home Turf Warrior from the team behind the Gaelforce adventure races positions itself at the premium end of the scene – with an entry fee of €65 to match. Taking place twice a year on a purpose-built course in the grounds of Killary Adventure Centre in Co Mayo, the event is designed to challenge competitors on a range of levels.

"We've made an investment of tens of thousands of euros to build the course and we make sure there are new obstacles each year," says Mona Purcell from Gaelforce.

With names like Skid Mark, Slime Vines and Entrails, the obstacles put participants through the wringer – literally in some cases – and are designed by Martin Hughes who built the bungee jump and high ropes at Killary Adventure Centre.

“As with all adventure races, you have to take safety into your own hands,” warns Purcell. “We build safely but people have to assess the risks for themselves as well.”

Broken bones
Although scratches and bruises are the most common injuries on the Irish scene, that's not the case with Tough Guy, the British race founded by an eccentric ex-military man in 1987 which styles itself "the safest most dangerous event in the world". Ambulances assemble at the finish line and broken bones are par for the course.

Tragically, earlier this month a competitor in a Tough Mudder in Virginia drowned in a pool at the bottom of an obstacle.

Not all of these events have to be so hard-core. Names like Turf Warrior, Runamuck and To Hell and Back suggest a certain machismo but race organiser Paul Mahon is keen to stress that Runamuck, which takes place twice a year, is "unashamedly happy to get the mammys and daddys, the gang of girls on a hen and the less gung-ho kind of people".

With more super slides than electric cattle prods and hay bales than vertical walls, it’s easy to see why Runamuck appeals to those looking for a fun day out. Even the running is a bit of a distraction for competitors looking for a few laughs in the mud – about 80 per cent of Runamuck participants do the 5km one-lap challenge, rather than the two-lap 10km version.

Similarly, Purcell says, Turf Warrior appeals to those who would probably not consider one of Gaelforce’s other events which can be notoriously difficult to complete.

"You can do it fairly unfit, but you can't do Gaelforce West unless you have trained," she explains. "It's 67km and we purposely don't offer a shorter sprint version. With Turf Warrior it's just 10km and most people can pull and crawl their way around that."

Good clean fun
There is certainly a market for Runamuck's brand of good clean fun in the mud: Mahon is now organising two events a year with a capacity of 5,000 for each one. He could attract more participants or run it more often but feels this would risk reducing the attraction.

“It’s all about fun and interaction, especially for the teams. They are looking forward to the Tarzan swings and the superslides – it’s what people come for – and the run is almost something that gets in the way. We have people doing the cha-cha around a farmyard at 9.30 in the morning and there’s not a beer bottle in sight,” says Mahon.

So why have obstacle races become so popular, so fast? “I think it’s because you don’t have to be super-fit and you can have a lot of fun,” enthuses Purcell. “You can be like a kid again and not have to worry about everyday problems for a while.”

It seems lots of people would agree with her.