image copyrightScott Seefeldt/Trashouse Pandaimage captionHighland Kings Ultra is a four-day race covering 120 miles on the west coast of Scotland
Ultramarathon competitors are used to "roughing it" in races, sometimes sleeping in bivvy bags at the side of muddy trails or even running through several nights.
They set themselves incredible long-distance challenges, often running through remote and difficult terrain.
But now a new ultramarathon race is being launched which gives them luxury few could afford – including butlers, hydrotherapy pools, speed boats and Michelin-star chefs.
Highland Kings Ultra, a four-day camping race covering 120 miles on the west coast of Scotland, costs £15,499 per person to enter.
In contrast, the 95-mile West Highland Way Race costs just £120.
image copyrightScott Seefeldt/Trashouse Pandaimage captionSpeedboats will transfer the runners to the Isle of Arran, for the final leg of the race
The organisers of the Highland Kings Ultra are calling it "the most exclusive, luxury ultra-run experience on the planet".
Race director Rebecca Silva told BBC Scotland the idea was for the runners to "race like a warrior but recover like a king".
She said: "The luxury element makes it very different to other races.
"It's aimed at professionals, who can afford it, who want a sense of adventure but want an element of luxury off the beaten track, in the wild and not in the typical places people explore."
Where are the world's most expensive races?
- The only running race known to BBC Scotland which costs more than the Highland Kings Ultra is the World Marathon Challenge, which involves seven marathons on seven continents. The entry is between 39,900 Euros (£34,112) and 42,000 Euros (£35,908), and includes accommodation and business flights between each country
- An 11 day trip to run The Last desert in Antarctica, including a boat from Argentina, costs $12,900 (£9,353)
- The Antarctic Ice 100km (62 miles) costs $18,900 (£13,707) and includes food, accommodation and flights from Chile
- The Marathon Des Sables, a seven-day race across the Sahara desert where runners carry all their equipment for 155 miles (250km), costs 3,270 Euros (£2,796) to enter
- The Atacama Crossing, which is seven days covering 155 miles (250km), costs $3,800 (£2,755) to enter
- Back in Scotland, the 95-mile West Highland Way Race, which is one of the world's longest established ultramarathons, costs £120
She said each of the 40 runners would be given tailored training plans for the seven months leading up to the race in April 2022.
"They will have sweat-composition testing at their local university laboratory so we know how to fuel their bodies," she said.
"They will have Zoom calls with physios and psychologists. We will help them prepare in advance to get race-fit in a seven-month journey leading up to the event, which is a world first."
The runners will be able to speak to ultra-running world champion Jon Albo and receive personal coaching from Anna-Marie Watson, an ex-army dedicated ultra-runner and coach.
image copyrightHighland Kings Ultra image captionThe Highland Kings Ultra route goes for 120 miles from Dalness on the Scottish mainland to Dougarie on the Isle of Arran
The race starts in Dalness in Glencoe, with a mountainous marathon to Dalmally in Argyll and Bute, two miles east of the tip of Loch Awe.
This is followed by 32 miles through hilly forest terrain to Loch Fyne, then 34 miles to Portavadie on the west coast of the Cowal peninsula, and finishing with 28 miles on the Isle of Arran.
Competitors then spend a night in a luxury campsite, followed by a gala dinner with explorer Sir Ranulph Fiennes.
The event is being run by outdoor adventure business Primal Adventures, led by an ex-forces Ayrshire man, Matt Smith, and managing director Rebecca Silva.
Ms Silva said: "We were asked by a group of French clients to organise a luxury running trip from the Isle of Aran to Inverness in 2018 and that planted the seed because the event was so successful.
"We have been arranging primal bush craft and adventure courses for years, so this has been an extension of that."
image copyrightScott Seefeldt/Trashouse Pandaimage captionThe campsites will be catered by Michelin-star chefs and have a butler
Ian Beattie, chairman of Scottish Athletics and race director of the 95-mile West Highland Way ultramarathon race, said he had never heard of a more expensive race.
"It will be interesting to see if there is demand for this event," he said.
"There is an element of criticism for commercial races, but people will decide what they want."
He said ultramarathon races organised by running groups and/or experienced runners were much cheaper because of the number of volunteers involved.
He added: "My advice would be to join a local running club as there are always qualified coaches there and people with a wealth of experience and knowledge."