It is one of world’s most gruelling classic endurance challenges with a combined ascent almost as high as Mount Everest.

But a 39-year-old father of three has broken the record for the notorious Ramsay’s Round, running and climbing some of Scotland’s most imposing mountains.

The challenge takes in 24 Lochaber peaks across 58 miles with a total climb of around 28,500ft. Banavie runner Esmond Tresidder set off from Glen Nevis at 3am on July 6 in a tortuous trail that takes in Ben Nevis, the Aonachs, the Grey Corries, the Easains and the Mamores.

Not only did Mr Tresidder complete the route, he ran it in a blistering time of 16 hours, 12 minutes, 32 seconds, narrowly beating the previous record, set by Jasmin Paris from Penicuik, Midlothian, in 2016, by just 81 seconds.

He set both a new summer and an outright record. Mr Tresidder, a PassivHaus eco-friendly house designer, said: “It was very tough, but I was expecting it to be.

“I originally planned to start at 3am so that any darkness could be early on and going uphill so it didn’t slow me down too much, but then the weather was bad the day before and wasn’t forecast to clear properly until later.

“I attempted it once, in winter, on skis, unsupported and largely on sight. I got as far as Fersit Dam going clockwise before bailing in a storm. “I wasn’t on sub-24 hour schedule but it was an amazing experience.

“This time I was going the other direction, in summer, without skis but with support.

“I’ve had it in mind for a long time, but my list of potential projects is quite long.

“I’ve been thinking about it properly for a couple of years now, pretty much since moving here in 2016. I wanted to try it last autumn but I didn’t feel fit enough.

“Some of the route I know really well as they are my local hills, but the hills further east are quite remote and I never normally run in them.”

Mr Tresidder, a one-time record holder for the Cuillin Ridge on Skye, was paced along one section by former record holder Ms Paris.

He said: “Running the final bit along the Grey Corries with Jasmin pacing was really special.

“The running is so good there and I was feeling good enough to still enjoy it, and she was admirably focused on helping me go as fast as I could.

“And the final sprint finish to the bridge was memorable, if a little too close for comfort.

“It was hard work going down the Ben. The whole way, the pace just seemed completely audacious.

“This sort of distance is new to me and I was surprised at how fast I was having to go to match Jasmin’s splits.

“I was within a few minutes of her splits all day which was really stressful but also really exciting and kind of cool.

“Setting off I really wasn’t confident I’d do it at all.

“I was hopeful I could have a strong performance, and I thought if I did that I might have a shot at the record, but there was a big element of doubt which kept things exciting.

“During the run the only place I was confident I’d get the record was on the summit of Ben Nevis when I was nine minutes up on Jasmin’s time.

“But then the descent was hard work in the dark.”

Mr Tresidder ran up to 50 miles a week in his training and ate around 300 calories an hour during the challenge, “which sounds easy but actually very hard when you are running”.

Originally, all 24 summits on the Ramsay Round were Munros, but Sgorr an Iubhair was declassified as a Munro in 1997.

The route was devised by Charlie Ramsay from Edinburgh, and a member of Lochaber Athletic Club, as an extension to an existing 24-hour walking route. His completion created Scotland’s Classic Mountain Marathon.

Mr Tresidder is raising money for the replacement of his local children’s playground and environmental campaign group Extinction Rebellion.