Luke Robertson and his wife Hazel are ambassadors for Marie Curie and were appointed “explorers in residence” by the Royal Scottish Geographical Society (RSGS) last week.
The couple, originally from Stonehaven and living in Edinburgh, will start their 2,000-mile expedition on Friday.
They plan to kayak a total of 700 miles, cycle 650 miles, then run 550 miles to become the first people to cross the frozen Alaskan wilderness in this way.
Luke, who had an operation to treat a suspected brain tumour in 2014 and has also had a pacemaker fitted since suffering complete heart block in 2008, became the first Scot to complete a solo, unassisted and unsupported trek to the South Pole last year.
He and Hazel, who both recently completed the Marathon des Sables, have raised about £85,000 for Marie Curie and hope to raise as much as possible from their adventures which will include climbing Mont Blanc when they return from their 80-day Alaska trip.
Luke said: “We wanted to go somewhere that would inspire us as well as inspire other people and Alaska is such a great wilderness – a huge expanse of amazing landscapes and wild animals – so it’s really enticing, but ultimately it just started with us poring over maps to see what had and hadn’t been done before.
“We’re aiming to become the first people in history to travel the full length of Alaska from south to north using only human power.
“It requires a 400-mile kayak through the Pacific Ocean and then we’ll be cycling 650 miles through south Alaska into the Yukon of Canada heading north and then we begin the running stage, which is 550 miles of running through the Arctic Circle, and we end with a final kayak stage which is another 300 miles through the Arctic Ocean in the very north.
“No-one has ever put the pieces together to do this challenge – the only way to get to the very northern tip of Alaska is by kayaking along the coast or flying in. It’s a world-first expedition.”
The couple met when they were teenagers at Mackie Academy in Stonehaven.
Luke added: “We work very well together, we’ve got our strengths and weaknesses – we can also tell if one of us needs a helping hand and if the other is a bit down.
“Hazel works full-time for a low-carbon energy company but has a sabbatical for this expedition.”
RSGS chief executive Mike Robinson said: “Luke and Hazel have wonderful energy and enthusiasm and are great role models for future generations interested in the world around them.”