At 9.37 am on the morning of May 4, a lone figure, moving fast and carrying little but a runner's waist pack, scrambled up the final rocks of the peak of Sgurr nan Gillean. Reaching the top, he tagged the summit cairn before turning back to see an awesome sight: the whole of Skye's Cuillin Ridge curving away into the distance for seven miles, its rugged crush of pinnacles and cliffs seemingly held aloft above a sea of cloud as though suspended in space.

"It was like running in heaven", says 27-year-old Es Tresidder, still emotionally moved by the memory. But it wasn't just the meteorological conditions that made Tresidder feel he was literally on cloud nine; he had just pulled off something very special indeed: the fastest traverse of the notoriously difficult Cuillin Ridge - and he had beaten the record by some margin.

While valley-bound hillwalkers and tourists below had bemoaned an apparently dreich day of mist and fog, 3000ft above Tressider had taken a full 15 minutes off the previous record in an unreal world of clear skies and dazzling sunshine during a dash across a mountain range perched above a temperature inversion.

"My performance is definitely dictated by the environment", says Tresidder, a top-flight mountaineer as well as runner. "I can be totally inspired by the landscape I'm running or climbing through and I really think the amazing conditions helped me to push myself to the limit".

To put this achievement in perspective it's worth remembering that it is less than 100 years since anyone actually managed to climb the whole of the Cuillin Ridge in one go, let alone attempted to run it. The terrain comprising the seven-mile long dragon's back of gabbro and basalt aiguilles contains nearly two dozen peaks or pinnacles, requiring 10,000 vertical feet of ascent and descent. One of them is the notorious Inaccessible Pinnacle of Sgurr Dearg - the only Munro that requires mandatory technical rock climbing; its final, thrillingly exposed shark's fin of rock famously stops many a hillwalker in their tracks.

Unsurprisingly, the ridge remains a considerable challenge for most climbers who are often content to spend two days on the journey with a mid-way bivouac. Chasing the record for the fastest traverse of the ridge is therefore a test of skill, nerve, speed and stamina like few other courses. It certainly sorts out the very best from the rest and is a much sought-after prize by the cream of climbing's cognoscenti. The record changes hands very infrequently.

"I'd been thinking about running the ridge since I was 14 really," says Tresidder. "I remember going on a camping holiday to Coruisk in 1994, looking at this amazing alpine skyline and hearing that someone had run along it; I thought that would be a pretty cool thing to do".

But it wasn't until over a decade later, with a considerable body of fell- running and climbing experience behind him, that he felt ready to tackle such a daunting course.

A respectable time for a continuous conventional walking and climbing traverse remains between 10-14 hours. But, when the legendary fell runner and climber Eric Beard completed the distance in 1967 in the amazing time of four hours, nine minutes, people were initially incredulous, and then sure it would never be bettered.

Beard, who died in a motorway crash in 1969, certainly left a long-standing memorial to his own prowess in the form of the record, which stood for 17 years until Cumbrian Andy Hyslop succeeded in bettering it by just four and half minutes.

The record changed hands only twice in the following eight years, with the running partnership of Paul Stott and Del Davies achieving sub-four hours in 1986 before Wester Ross-based mountain guide Martin Moran smashed the record with a 3.33 run four years later.

Former title-holder Hyslop then reclaimed the crown in 1994 by shaving just 10 seconds of Moran's time. A second attempt by Hyslop the same year only succeeded in taking the time down to 3.32.15. It seemed like some kind of physiological barrier might have been reached, but, this spring, Tresidder comprehensively proved the pundits wrong with an astonishing time of 3.17.28.

"It's a unique run," thinks Tresidder, "there's nothing else quite like it. I've run a circuit of the hills around Glencoe taking in the Aonach Eagach for example, but that seems like an athletics track compared to the Cuillin.

"You really need to be a climber as well as a runner, since you're quite often using all four limbs at the same time but moving very quickly."

Tresidder wore a pair of fell-running shoes re-soled with "sticky" rubber for his run, which helped his security on the climbing sections such as the dauntingly slippery basalt of the ridge's Thearlich-Dubh gap (normally abseiled), the King's Chimney, the frighteningly exposed Naismith's Route on the Bhasteir Tooth and, of course, the Inaccessible Pinnacle.

"I certainly felt nervous the night before," admits Tresidder, who confesses he feels uncomfortable with solo climbing. "The nearest thing I can compare it to is the apprehension you might feel before attempting a big Alpine North Face; the enormity of what you're about to embark on hits you and you can't help falling prey to self-doubt. But the funny thing is that once you get started the concentration blows a lot of the fear away.

"In the event, I felt fine on the technical climbing sections because I deliberately forced myself to take them steadily and not rush the moves - in reality the running sections are the dangerous bits - they are mentally exhausting."

Tresidder says that he reckons it took about a fortnight for him to come down from a high of elation and mental exhaustion following the run.

"It's difficult to describe, but when I finished, apart from some sore knees I felt in pretty good shape physically, considering I'd been fell running for over three hours. But my mind was total mush because of concentrating so hard. I was utterly drained mentally because you have to keep up your guard every step of the way.

"Although I didn't trip once I was acutely aware that a simple mistake could prove fatal in many places and as a result, although I was aware there was this amazing thing going on with the weather, it wasn't until I stopped I could really relish the astounding beauty of the whole thing."

But that wasn't the end of the challenge - Tresidder, who had travelled to Skye by bus, still had to hitch back home to Edinburgh to be ready for work at the Sustainable Communities Initiatives energy-saving eco-house "Earthship Fife" at Kinghorn Loch.

Such a green approach to travel in the hills is nothing new to Tresidder, who boasts a degree in ecology from Edinburgh University. The former Edinburgh City rickshaw-puller has been known to use bicycles to get to the base of Scottish winter climbs and recently wrote a detailed feature for a leading mountaineering magazine on how to reduce climbers' carbon footprints.

How long does he think his record will stand?

"You could definitely do the Ridge in a faster time," he thinks, "but there aren't that many people with the right mixture of abilities, so I can't think of anyone at the moment."

As for his own future plans, apart from pursuing his passion for Scottish mountaineering and Alpinism he fancies taking on one of the toughest fell-runs in the world - The Ramsey Round - 24 Munros, 60 miles and 28,000ft of ascent around Glen Nevis completed within 24 hours.

"But I fancy trying to do it in winter", he adds with a glint in his eye. "I don't think anyone's managed that yet."

But if anyone can, it's probably Scotland's fastest mountaineer, Es Tresidder.

You can learn more about Es Tresidder's mountain exploits at: www.es-on-ice.co.uk