She is the Paralympics gold medallist who is paralysed from the chest down but with a ravenous appetite for feats of derring-do.

He is the former railways worker from Edinburgh who dreamed of being the best despite disability.

Together Karen Darke and Ken Talbot have become Scotland's newest world record holders - in hand-cycling.

Both speed feats were performed while sat inside Arion4 an enclosed hand bicycle pod designed by engineering students from the University of Liverpool in which the riders only see the road on a screen.

Whether it is hand-cycling across the Himalayas, sit skiing across the Greenland ice cap or travelling or climbing the 3,000-foot cliff El Capitan in Yosemite, Inverness's Karen Darke is in her element.

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But the 47-year-old's latest escapade with Mr Talbot set against the golden yellow sand carpet of the semi-arid Nevada desert is far away from the extreme adventures she has devoured - and has amazed some of her closest colleagues.

This time it is about human powered bicycle speed racing and even watching it is not easy.

The instructions for spectators on the desert plateau spell out the difficulties - limited parking and no services and warnings that warm clothing is needed for the cold of the mornings and evenings.

On two consecutive days as the sun came up on Nevada State Route 305 she broke the female hand-cycle land speed record not once, but twice over the flat 2.5 mile course. And in so doing she even managed to surpass an old men’s world which had been standing for seven years. In her velocipede on Wednesday morning she set a speed of 41.86mph - 17mph faster than the previous world record.

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Pictures by ULV team

But she was merely warming up, because on Thursday morning she added nearly 5mph to her own mark with a speed of 46.05mph.

Before the arrival on American soil, the arm powered male world record was 45.68 mph and was set in September 2011 by Greg Westlake from Avos Arrow. The female world record was a mere 24.85mph and was set in September 2016 by Sarah Piercy from Plymouth University.

It is, perhaps, apt that Ms Darke who was victorious for Great Britain in hand cycling at the 2016's Rio Paralympics, should complete the feat near the quiet town of Battle Mountain, dubbed 'the town that gold mining saved'.

"I surprised myself," she said Ms Darke, who admitted that she "freaked out" when first trying out the enclosed bike she described as "like an egg".

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"It is one of the most surreal experiences of my life, because to sit in this pod and crank it up that highway, because I have never done it before, well it feels pretty extreme," she said. But it did not end there, as Mr Talbot who with Ms Darke are part of the University of Liverpool Velodipede team broke the men's record and became the first hand-cyclist to go over 50mph in history with a time of 51.86mph.

Mr Talbot, who got into hand-cycling ten years ago had his training disrupted for a week and a half because of flu but said: "When I was a little kid, I wanted to be one of the people who went up there and set a record."

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Both were taking part in the 19th annual World Human Powered Speed Challenge where teams from France, Russia, Japan, Canada, Italy, Mexico, USA, the Netherlands and Britain, bring their high-tech pedal powered bikes to achieve amazing speeds.

The high altitude and arrow straight section of road has attracted athletes worldwide to test their speed bike designs and sprinting abilities since 2000.

The thin air at 4,619ft altitude reduces aerodynamic drag, which coupled with the five mile long acceleration zone enables the bikes to reach their maximum velocity before being timed over a 200 metre distance.

For Ms Darke, this was an interlude in her latest adventure, Quest 79, a project to undertake a total of nine hand-bike rides on seven continents while raising money for charity and encouraging others to take on their own challenges.

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"After Rio I was looking for a new challenge and I heard about this event and I just fancied it," she said. "This was the first time the University of Liverpool had produced a hand-powered bike so I went to visit them and basically said I want to be your female rider. And they said it was okay.

"I never sat in it until a week before I came our here when I had a few runs on an old runway somewhere near Manchester. So I was on a big learning curve and it was such a surreal experience to be sat in, basically, an egg. It's very very different to riding a regular hand-bike.

"The first time I tried it on the first day I freaked out. I did go fast but your senses are completely altered. It is so noisy inside and all you can see is the road on a screen. It's not the actual road.

"You are just adjusting to everything, the dimensions are different, there's no window, your depth of field is distorted, there are so many things that are new. It has hardly any steering so if there is a gust of wind it blows you off and it is hard to correct it."

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She was 21 when she fell about 33 feet off a sea cliff while rock climbing in Scotland, breaking her skull, arms, neck and back. After three days in a coma, she woke up and was told she was paralysed from the chest down. She's been in a wheelchair ever since.

Her first expedition after her accident was a hand-bike ride along the Silk Route from Kazakhstan to Pakistan in the Himalayas in 1997 and others followed.

"Why do I do these things? It's like trying to say why you are the way you are. I like challenging myself. I like adventures. I like the whole experience that it brings of meeting people and having new experiences and new encounters.

"Life is to be lived and experienced and that's what I like to do."

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