Exhaustion and solitude: Yukon Arctic Ultra runners kick off 690-km race

Sled dogs and mushers aren't the only ones dashing down the trail toDawson City this week.

The Yukon Arctic Ultra started in Whitehorse on Sunday, where the temperature sat at 19C.

Forty runners have signed on to the 690-kilometre race,which follows the mushers' path. But unlike the sled dog race, there is no prize money waiting at the end of the marathon. The only reward is the knowledge youfinished the run that organizers billas "the toughest ultra race in the world."

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Runners pull their own supplies on a pulk, a small low-slung toboggan, and have 13 days to complete the journey.

Some nights are spent at checkpoints, while on other nights, runners camp alone in the wilderness.

Race organizer Robert Pollhammersays, on average, about 60per cent of runners make it to Dawson City. Some try multiple times over the years before making it all the way.

Rejean Moreau ofQuebecis attempting it for the third time.

He's using a newly built sled part kick-sled,part pulk whichhe designed.Itcan be pulled or pushed as needed.

"You have to be totally autonomous," saysMoreau.

"You need food for at least 48 hours, you need your camping kit. Obviously some other clothing or something to change your gear. First Aid, arepair kit."

Competitors this year also come from Australia, New Zealand, Italy, Germany,Austria, Sweden, Denmark, Brazil and other countries.

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Twenty-eightYukonershave signed up, with most covering short distances,such as the marathon.

Some runners finished themarathon on Sunday, while others will travel 160, 321, 482 or the full 690 kilometres. In the shorter races, competitorscan run,mountain bike or cross-country ski.

'At night the demons come out'

Those running the ultra raceface exhaustion, long hours and solitude on the trail. They often run overnight, with the way illuminated only by head lamp.

The combination of fatigue, repetition and shadowscan play tricks on the mind, says Scott Smith.

The 48-year-old runner from Scotlandsays that in a previous race, he began to hallucinate. Last year, hesaw a woman in a summer dress on the trail.

"I thought, 'why is she here? She must be cold,'" he recalls.

"She was as real as you are standing there. But as I approached her, it turned out to be a small sapling covered in snow."

As Smith kept walking, he says, more frightening images started to appear from his dreams and subconscious. He saw a witch and a demon with horns.

Even more strangely, he recalls seeing Woody, the cowboy from Toy Story.

"He stood on the trail,life size, hands on his hips just looking at me. That really freaked me out. It took me several minutes before I could sort my head out and get moving again."

Smith says a wandering mind can be dangerousbecauserunners needto trust theirjudgment.

One risk is a dazed runner "fallingasleep while walking"and collapsing in the snow, he says.

Medical team watching

Many runners have suffered frostbite to varying degrees.

Pollhammer says there's a medical team at every checkpoint, and team members havethe authority to overrule a runner and take them out of the race if they are dazed or ignoring orders.

"They have a look and talk to the runners to see if they are all right. They're here to help us avoid problems or deal with them right away."

10,000 calories a day

Runners will be eating rich food along the trail. The cold weather and exertion means runners consume more than 10,000 calories a day.

"I've got sweet stuff, salami, cheese, porridge, all sorts of things," says runner Shane Mooney, who's from Ireland.

Runners also carry ultra-light stoves to melt snow for drinking water.

Mooney says he travelled to Yukon precisely because the Arctic Ultra is so difficult.

"I think it's just the adventure of it, the cold, the isolation, the darkness that draws people. For me. I love the idea of that last section of the trail where there's less support," he says.

"It's a long way to come and I thought I'd go for the big one."