Eoin, who has broken several long-distance running records, finished first of the 2,000 global competitors who set off on the gruelling 170km UTMB race through the rugged mountain interior of Oman on the Arabian Peninsula last week, in a time of 36 hours, four minutes and 29 seconds, beating home-favourite, Omani runner Hamden Al Khatri by almost three-hours.

The race, under the hot Arabian sun, over challenging exposed mountain ridges three times higher than Carrauntoohill, and through palm-filled wadis and abandoned ancient villages of the Sultanate, presented a unique physical and mental challenge.

But it seems that for Mr Keith, the longer the race, the easier it gets: “I couldn't do a 100-metre sprint. But the older I got, the more endurance I found I had and the easier I found the longer races."

"170km seems like a huge undertaking but when you break it down into components, it’s not that difficult. It was so technical, possibly the most technical race I’ve ever done.

"There was a long 1,000m descent which you normally would expect to make tons of time on but we were so slow.

"It makes it easier to keep going mentally because it’s so technical that you need to concentrate pretty much the entire time.

"There’s no real let-up mentally and it was intense racing all the way. But very enjoyable.”

Race organisers include a branch-off to a shorter course at the 120km mark but Eoin said he was in “racing mode” throughout.

He got a full medical check at the diversion point which took about five minutes and said it never crossed his mind to take the shorter course: “That medical check was my longest stop. I was totally mentally engaged throughout and there was huge elation when I finished.

"I was on an absolute gigantic high. It ranks as one of my best ever achievements."

Eoin, who works in the IT department of the Royal College of Surgeons, was joined in Oman by his wife, Helen Dixon, who completed the 50km race.

Just days later, they were home finalising travel arrangements to spend Christmas in Gran Canaria, where Helen hopes to undertake several runs and Eoin will head for the mountains on his bike in preparation for the next big race.

In January, he is taking on the Spine Race - an epic 429km run along the Pennine Way - the backbone of England - where he will face difficult winter ground and weather conditions.

Competitors can expect to spend up to 100-hours across four days tackling the course.