It's been a busy time for endurance enthusiasts - those resilient, single-minded types who think nothing of walking the length of Africa barefoot, or sailing solo across the Pacific.
This week alone saw British explorer Sir Ranulph Fiennes finish a record-breaking seven marathons in seven days on seven continents. Frenchwoman Raphaela Le Gouvello completed a three-month windsurfing epic across the Pacific, even as ocean rower Jim Shekhdar of Britain set off on his own odyssey - a 9,000-mile, seven-month rowing marathon from New Zealand to South Africa.
The sudden explosion in such feats of endurance prompts a simple question: Why do they do it?
Sports experts, psychologists, and endurance fiends themselves offer a host of reasons. Some put it down to Info Age ennui - a frustration with the ease of contemporary life. Other say the "Guinness Book Generation" is merely the latest extension of the age-old urge to test man's limits and assert his mastery over nature.
"Increasing numbers of people in our society are cheesed off and want something to break away from the monotony of modern life," says ocean rower Simon Chalk of Britain.
"It's about setting a goal, going after it, and achieving it - that has always motivated people, no matter what they do," says Mr. Chalk, who earlier this year became the youngest man to row his way across the Indian Ocean in an epic 109-day, 3,200-mile escapade.
Daredevil feats of stamina and fortitude are in themselves not new phenomena, of course. Explorers have been pushing back the boundaries on land, sea, and air for centuries; it's been decades since the polar caps were tamed and the highest mountains climbed.
Some suspect the recent predilection for feats of unimaginable stamina reflects an attempt to contrive new challenges in an overexplored world.
"It's a bit of a cult phenomenon - it's as much sociological as physiological," says Mike Smith, a mountaineer who is director of sport at the University of Warwick in central England.
"Mankind has got an exploratory urge - it's just channeled in different ways these days," he says.
"It's part of the great exploratory wave that people are looking to replicate, but they have to contrive it because there are no frontiers that haven't been explored."
Take the South Pole, for example.
Less than a century ago, it remained untamed - a deadly and terrible place for would-be conquerors.
Now, as the Southern Hemisphere enters its summer, the Antarctic will be a crowded place with dozens of adventurers seeking some entry into the annals of extreme history.
Or consider the marathon, that legendary discipline of Greek myth revived in 1896 as an Olympic sport and then, a generation ago, as an event for amateurs. In the early 1980s, a few thousand took part in the top 10 marathons around the world. Last year, almost a quarter of a million ran.
Yet running a marathon is a very different challenge from some of the more extreme exploits nowadays. People no longer just climb the Himalayas, they try to ski and snowboard down them. They don't just sail round the world, but row, run, walk, or cycle. No longer content with a mere marathon, they compete in ultramarathons of 100-plus miles or run seven marathons in seven days.
Mr. Fiennes and Mike Stroud finished their seventh marathon in New York last weekend, running in a field of 35,000. The men also ran marathons in the Patagonia region of Chile, the Falkland Islands, Sydney, Singapore, London, and Cairo before New York.
In 1982, Fiennes became one of the first men to reach both the North Pole and the South Pole on his Trans-Globe Expedition. In 1993, Mr. Stroud and Fiennes became the first men to walk unassisted across the Antarctic pulling a sled.
Dr. Alan Maryon Davis, an expert in health and lifestyle at King's College, London, says that the growing numbers of endurance enthusiasts may be linked to the kind of society we live in.
"We have such a cosseted existence these days that many people really need a personal challenge," he says. "Our parents and grandparents had world wars to fight and didn't have to prove themselves. It is part of human nature to get the adrenalin going and push oneself."
Growing prosperity and greater leisure time play their part too. More and more people are in a position where they can take months or even years out of their life to seek adventure. Bosses can be assuaged by adding a charity dimension to the project, and costs can be borne by corporate sponsors.
"People have more time, more money; there is more modern technology at a person's disposal," notes Mr Smith of Warwick University, adding that the modern world has also mitigated the risk for adventurers.
"People would be less inclined to do these things if the penalties were as severe as they used to be," he adds. "The penalties these days are to be quickly rescued, because there is nowhere you can go without being in contact."
Still, some activities are plainly a health hazard, experts say. The old adage, "That which does not kill me makes me stronger" only works up to a point.
"Often you wouldn't advise people to do these things, because it is a risk to their health," says Professor Mike Gleeson, an expert in endurance exercise physiology at England's Loughborough University.
"You can overdo it," he warns.
Those joining what might be dubbed the 2003 Endurance Hall of Fame, already include France's Maud Fontenoy, the first woman to row the Atlantic from west to east, Briton Andrew Cooney, the youngest person to trek to the South Pole; and Tanya Streeter from the US, who claimed a free-diving record by plunging deeper on a single breath than any rival .
For Simon Chalk, crossing the Indian Ocean was formidable. Every day for 109 days, he rowed his small boat for 10 hours at a time, a small dot in a vast ocean expanse with just the flying fish, the sunsets and the storms for company.
Battling sleep deprivation and fierce heat, mountainous seas and utter isolation, he powered on, the sun burning his back through his top, his cabin filling with water as the Indian Ocean's violent swell took its toll.
But he says the physical challenge of spending more than three months in the 20-foot rowboat was compensated by the unique chance to clear his head of the clutter and babble of modern life.
"You have a chance to put everything in order," he says. "Not only your own decisions but everything around you. There were incredible highs and incredible lows, but the most testing thing after that much time alone was coming home."