Mark Beaumont in bid to cycle around the world in 80 days
The adventurer is aiming to cycle round the world in 80 days - less than half the time he took to complete the route more than nine years ago.
He will then ride for China via Lithuania, Russia and Mongolia, before cycling between Perth and Brisbane in Australia while also taking in New Zealand, the US and Canada.
The 34-year-old hopes to complete the final leg from Lisbon to Paris by September 21.
Beaumont said: “This is my chance to shoot for the stars and take on the ultimate endurance cycling challenge.
“Since I last pedalled around the world nearly 10 years ago, there has been a growing desire in me to push the boundaries of what is possible and to retake the circumnavigation world record at a whole new level.”
His Artemis World Cycle covers 18,000 miles, which means the Scot will have to complete 240 miles a day - spending 16 hours in the saddle.
In 2008, Beaumont completed a cycle around the globe in 194 days, setting a world record.
Since then, the record has been whittled down to 123 days by New Zealand’s Andrew Nicholson.
Beaumont will therefore have to break the existing world record by more than 40 days to achieve the tough target.
This time though, he will be accompanied by a mechanic, nutritionist, physiotherapist and manager on his tour, unlike his 2008 solo ride.
Before setting off in the early hours of Sunday morning, he said: “I know what I’m getting myself into, this will be the toughest challenge of my life and will be an immense physical, mental and logistical battle before I reach the finish line.
“I have spent the last three years creating an amazing support team, who are in charge of my nutrition, logistics, navigation and safety, allowing me to purely focus on my performance and being an athlete.
“I don’t think anyone has ever tried to go this fast and this far before and I have been building on my experience as an endurance rider over two decades to prepare for this journey.”
The adventurer warmed up for his world record attempt by cycling 3,300 miles around the British coastline in April.
As well as the world record, he aims to raise £10 for every mile cycled, a total of £180,000 for Orkidstudio, which works to benefit communities worldwide through innovative architecture and construction.