Few sports make mountain climbing and around-the-world sailing seem almost tame, but the Dakar Rally rates among the world's great challenges.
This year's rally kicked up the dust on Saturday, more than 6000 kilometres from Dakar, after it was moved to South America in response to last year's race being cancelled because of concerns about terrorist attacks.
More than 500 vehicles, including four Australian entries, crossed the starting line in Buenos Aires before vast numbers of spectators. There were three Australian motorbikes, one SUV and an Australian mechanic riding on a Spanish heavy-truck entry.
Still called the Dakar Rally, the race is being run through Argentina and Chile this year. The motorbikes, four-wheel quads, cars, light and heavy trucks will travel 9574km, crossing the Andes twice, driving across Chile's brutal Atacama Desert and returning to Buenos Aires 14 days later.
"I expect to suffer," defending motorbike champion Cyril Despres of France said. "The race is never easy, particularly when you really want to win. Everything is there to challenge you intensely: heat, the long hours riding and the altitude." The riders cross the Andes at more than 5500 metres.
To prove his point, Despres got a flat tyre inside the first hour, changed it, but lost the new tyre near the finish and completed the special (or timed section) on his bike's rims. He was 41 minutes behind the leader, perhaps already ending his chances of winning the rally.
The terrain throughout the race ranges from easy grasslands to brutally difficult rocky conditions to 150m sand dunes to scorching, rocky desert plains and a mountain pass where drivers will struggle for breath.
Only about half of the entrants will finish the race. Most drivers talk not of physical prowess or driving ability but of the "mental and emotional strength required to finish" one of the world's most difficult challenges.
This easily rates as the world's most dangerous sporting event. Organisers say 48 drivers have been killed during the previous 29 races, along with several dozen spectators, almost all in Africa.
Australian motorcycle rider Andy Caldecott died in 2006 from neck injuries sustained in a crash. The race's founder, Thierry Sabine, was killed in 1986 when his helicopter crashed.
"You really don't think about the danger," says Christophe Barriere-Varju, 36, a Frenchman who came to Australia in 2001 and this year is running his third Dakar under the Australian flag on a KTM motorbike. It's a standard sort of answer for anyone involved in extreme sports, but he insists, "It really is about the challenge."
Barriere-Varju is typical of many of the competitors. He has an MBA and founded a business consulting firm in Sydney. He has been racing motorbikes for 20 years.
"I first got interested in the Dakar when I was living in Africa in the 1980s. It was huge there," he says.
Australian Bruce Garland, 50, is a long-time rally racer and five-time winner of the Australian Safari. He is back for his second Dakar attempt. His first, in 1998, he failed to finish - like most first-timers. He was again at the starting line last year when the race was cancelled. This year he is back with the Isuzu D-Max team and navigator Harry Suzuki; the team's two trucks are the first vehicles built in Australia to contest the Dakar.
Garland's attitude seems stereotypically Australian: "Well if we don't win the race at least we'll win the parties." But his jovial attitude masks a serious intent. He says he wants to finish and to win.
The Australian contingent is rounded out by bike riders David Schwartz and Simon Pavey and mechanic Richard Hayes, who rides along with two Spanish drivers in an 11-tonne truck.
The death toll, particularly among spectators, means the race has its critics, and there were regular protests at the starts in Europe. But in South America the locals are enthralled.
Gilles Duceppe, a member of France's green party, is a staunch race critic and was in Buenos Aires for the start.
"I think at least 50 innocent people have been killed by these crazy men and women," he says. Despite what organisers say, he believes many of the deaths of innocent bystanders killed in Africa go unreported.
In his first Dakar, in 2006, Barriere-Varju hit a rock in Morocco and was thrown from his bike. "I dislocated my shoulder," he says. "But after 20 minutes I put it back into its socket by myself and got back on and kept riding." After another 180km, he was thrown again and broke three ribs. "I didn't finish the race."
He did finish the 2007 Dakar "mostly without incident", he says. He was 64th out of 248. "After completing the Dakar I felt that people really complain about a lot of unimportant things. Now I just dismiss people who endlessly complain about meaningless little things."