The sweat-soaked, not-for-novices sport of adventure racing – where courses can take a day or longer – is perfect for the rugged, spectacular terrain of Ireland’s wild west coast.

Once the preserve of only elite athletes, adventure racing has become one of the fastest-growing sports on Earth. Technically a team event that includes an element of navigation, the term adventure racing has now grown to describe any race using two or more disciplines, such as running, biking or kayaking. A related sport – endurance racing – uses just one discipline.

Either type of race takes competitors through terrain so challenging, simply crossing the finishing line is considered a victory. That has made Ireland, with its large tracts of sparsely populated moorland, rugged mountains and windswept valleys, a perfect setting for many of these challenging, unusual sports.

Ireland’s first adventure race, Gaelforce West, is a 67km challenge that includes mountain running, cycling and kayaking around Ireland's only fjord, Killary Harbour. Started in 2006 with just 130 competitors, it now attracts up to 3,000 athletes to its annual competition every August. The wild geography and topography around Killary, with its gorse-covered mountains, sweeping valleys and white sand beaches, presents both stark beauty and physical challenges. "Adventure racing gives you a goal and a focus, and the opportunity to experience a very rugged part of the world – but under safe, controlled conditions," said Gaelforce organiser Ciara Young.

Like the area around Killary Harbour, much of Ireland's west coast is untouched; generations of emigration and harsh weather have left it practically pristine. If you fancy seeing the region on foot, the 200km Kerry Way Ultra crosses prehistoric roads, famine graves, abandoned villages, hilltop burial chambers and ancient standing stones. This incredibly tough cross-country course, which takes place every September, has a cut-off time of 40 hours; the 2013 winner crossed the finish line in just over 27 hours.  

“Rather than altitude gain or temperature, it's the terrain that is the difficulty here," explained Jens Waechter, a German ultra-runner who lives in Ireland and placed second in the 2013 race. "The route covers everything from road running to cross-country fell running, with sections right through undeveloped bog. This doesn't really exist in any other ultras. They all go along maintained trails."

Along the way, the run offers magnificent views of Ireland's highest peaks – the 1,000m-high McGillycuddy Reeks – and some of the country’s most iconic seascapes and lonely glens. By night, when runners cover the isolated Iveragh Peninsula, the views are equally stunning. Recently designated a Dark Sky Reserve for its lack of light pollution and the exceptional quality of its night sky, Iveragh is one of only seven such reserves in the world and the first in the northern hemisphere to get gold-tier status, the highest possible grading issued by the International Dark-Sky Association.

Although the Kerry Way Ultra is only in its second year, the event is already attracting international attention. Just 15 competitors started the race last year, only three of whom managed to finish. With five months until registration closes, the 2014 race already has 25 athletes signed up.  

At the other end of the country, in northwest Donegal, an event known simply as The Race was held for the first time in early March 2014. Billed as Ireland's toughest multi-sports race, it challenged its 54 competitors to cover 260km of kayaking, cycling and mountain road and trail running within 24 hours. Set in a barrenly beautiful area that sees relatively few visitors, the route took in the gorgeous beaches at the town of Downies, the remote cliffs of Bloody Foreland and the beautiful Glenveagh National Park.

Bill Wells, an experienced Canadian adventure racer, won The Race with a time of 15 hours 22 minutes – but he said it was one of the toughest solo races he had done, thanks to the hills, wind – and eventual rain, hail and snow. Of the 54 competitors, 38 managed to cross the finish line.

Although it takes a huge commitment to compete in an event such as The Race, it’s a unique way to explore Ireland's magnificent landscape. "It's a great way to see the world," said Wells. "You see places you'd never go to otherwise. I'm sure there were many locals there who have never been up Muckish [Mountain] or seen some of the crazy waterfalls we encountered along the route."

If an endurance race is too much to take on, the Irish Triathlon website lists many races that can be done in teams, as relays or with more manageable distances. All offer routes across starkly beautiful countryside, instant friendships – and, of course, life-long bragging rights. After all, there are few finer places than Ireland to beat your body into submission.