Grant Curle has a unique way of beating Toronto’s winter blues.

When the temperature drops, Curle throws on a jacket, grabs his toque and runs through the city streets in his bare feet.

“The snow under your feet feels fantastic,” said Curle, 37. “It’s like constantly stepping onto a surface that perfectly forms to your foot. It’s perfect.”

And he’s not alone. A faction of diehard Canadian barefoot runners will jog on snowy roads, trails and parks this winter with no more protection than the hair on their toes.

“You get some bragging rights. It’s an interesting experiment to see how far you can push yourself,” he said.

Once regarded as fanatics, barefoot runners have wiggled their way into the mainstream running world. Supporters point out that shoeless marathoners and Olympians have set world records; others say it stimulates untapped nerves lying dormant in our socks.

Shoes that simulate the barefoot feel have since been adopted by Nike.

But those who run barefoot in the snow?

“You could say we’re a fringe of a fringe,” said Rod Begg, an Ottawa-based barefoot runner. “Some use the word ‘crazy.’ ”

Begg is the brains behind the Winter Challenge, a competition that pits runners from Canada, the United States and Europe against each other in a sub-zero marathon. Participants log their runs online to see who can get the most.

He started the competition in 2010 through the Barefoot Runners Society, an online network of more than 5,000 runners.

“I took barefoot running up in 2010, and in the winter I was getting jealous of people posting running results when they were in California and Florida,” said Begg, 52. “I thought, Well, why can’t I run now, too.”

He posted a document on the Barefoot Runners Society website that allowed runners to log kilometres completed under 5 C. They also stated their country, a distinction that quickly divided the competition.

“There’s a subtle rivalry between the U.S. and Canada,” he said. “This is the fourth year of the Winter Challenge, and the Americans have won two of those. It’s our turn to even out the score.”

This will be Curle’s first year in the competition, but he started running barefoot in Toronto’s winter last year.

“The coldest I ran was about minus 10 C, minus 15 C, basically as cold as it got in Toronto last winter,” he said.

Besides bragging rights, Curle, a personal trainer, said he does it for health reasons.

“The best part of barefoot running in the winter is the surge in metabolism,” he said. “There’s a definite metabolic reaction and it actually warms the feet. The colder it is, the more the blood flows.”

“Running in the cold, I’ve built up a muscle tone like wood. Working in the cold makes you hard. It also builds up the central nervous system a lot.”

But claims of a heightened metabolism may not hold weight, according to an expert in body temperature regulation.

Ira Jacobs, a dean and professor at the University of Toronto’s department of kinesiology and physical education, said that as long as a person is exercising hard enough, the lack of shoes won’t make a difference in metabolism.

“If people are running, it’s not particularly applicable to them,” Jacobs told the Star. “But if you’re walking at a low intensity and it’s very cold, then, yes, the odds are you require a few more calories.”

Running barefoot through snow poses risks of frostbite and frostnip, he added.

Loading... Loading... Loading... Loading... Loading... Loading...

“If you’re talking about minus 20 C on the surface of the skin, constantly touching things that are at the same temperature, it could do damage to the skin,” he said.

But that’s a risk many are willing to take.

“I’ve had a low-grade frostnip, which basically means that it’s starting to get towards frostbite,” said Bob Nichol, a barefoot runner from Winnipeg. “That was my first year not knowing what the limits were.”

Nichol, 42, has since mastered the sport. He holds the Winter Challenge record for the coldest run at minus 32 C. He hopes to beat that by at least a degree this winter and push his distance.

“I want try to surpass 300 kilometres, last year I finished around 250 kilometres,” he said. He had already logged 211 kilometres about a month into this year’s challenge, which began Oct. 1.

But he knows when to stop.

“Your feet will have pins and needles — that’s OK. But when the pins and needles stop and you can’t feel them, that’s the time to stop,” he said.

The toughest part of the Winter Challenge isn’t the snow, the frigid temperatures or even the ice, Nichol said. It’s the salt.

“It’s used to tenderize meat, so you can only imagine what that’s going to do to your feet,” he said. “I tend to stay away from the roads.”

The only other obstacle is the inevitable hecklers, who often cast judgment from the snug safety of a heated car.

“They all think I’m nuts. But it’s kind of a personal thing. People tell me I’m crazy for doing this, but that’s their opinion,” he said.

“I like to push the envelope to see exactly what the body will do.”

Online

Grant Curle explains his love of barefoot running. Go to thestar.com/life to watch him