Ed Tumavicus claims he is not clinically insane, and he should know. He’s a physician.

Yet on Friday morning, when the air around Back Cove hovered around minus 10, and before the sun could burn off the last tendrils of sea smoke, there was Tumavicus, 54, defying common sense to get in the first half of his daily, 6-mile run, which doubles as his commute to his practice at Maine Medical Partners in Portland.

He is one of the few runners whose commitment to fitness is so great, or whose stubborn streak runs so deep, that not even record cold can keep them from lacing up their sneakers in an act of seasonal defiance. Although there are fewer of them out in January than in July, runners who embrace winter seem to transcend the act as a mere expression of exercise.

It is an act of defiance, which begs the deeper question. Are you nuts?

Tumavicus smiles. The tiny balls of ice that have nestled into his facial hair crinkle around the corners of his mouth. “My family would say yes,” he said. “I have to tell people ‘be healthy’ and that kind of stuff. So you get out, you get some good clothes on. I’ve been singing ‘Feliz Navidad’ as I’m running.”

Unmatched goes the power of song, and human locomotion, it seems.

In interviews with runners on the coldest morning of the winter so far, all insisted that they were not, in fact, cold. Some even seemed chipper, and despite insistent skepticism, indicated they were glad to be outdoors.

Common among them, other than a malfunctioning limbic system, was an embrace of the simple adage that there is no such thing as bad weather, only bad clothing.

On this day, Tumavicus, for instance, had chosen a form-fitting windbreaker made of a subtly patterned, aqua-color material that appeared as if it had been borrowed from a NASA facility. Under that, he wore a short-sleeve T-shirt and a thin long-sleeve top, along with cold-weather tights. All are designed to wick away moisture.

When sweat evaporates, he explained, it takes heat along with it. Dressing right is a balance.

“Most people, when they run in the winter, they overdress. Then they get sweaty, and once you get sweaty, then you’re screwed,” he said.

Tumavicus, in his conclusion, seems to ignore the growing field of research that proves lying on one’s couch while holding a cup of tea is a far more efficient way to prevent perspiration.

Another devotee who appeared willfully ignorant of the science was Ryan Collins, 32.

He, too, showed early symptoms of acute climatological indifference. Collins, sporting a frosted mustache behind a frozen balaclava, said he dressed in three layers on the bottom and two layers on top, perhaps living dangerously in only a single pair of socks. Invisible to the naked eye, however, was his boundless determination. His plan was to run 9 miles.

“The blood’s circulating,” Collins said, before setting off on the shoulder of Baxter Boulevard. “I feel pretty good.”

According to running experts, after choosing proper dress and updating one’s last will and testament, the next most important step in preparing for cold-weather running is a proper warm-up.

Dan Frey, a physical therapist and strength and conditioning coach at OA Centers for Orthopaedics in Portland and an inveterate cold-weather runner, said that other than slip-and-falls, improper warm-up is a common source of injury.

“People who walk out the door and truly aren’t warmed up, and they’re still in that cold phase before they’re warmed up and pull a muscle or strain something,” Frey said.

Frey counsels runners to wear traction devices, too. Other than avoiding a fall, wearing spiked clip-ons over sneakers helps prevent injury or overuse of the tiny muscles in the feet and lower legs that stabilize and balance the body during motion.

It’s advice that Eliza Grinnell has taken to heart.

Grinnell, 48, charted her course along the plowed path near the water’s edge. On the soles of her feet were a set of chains adorned with shiny steel micro-spikes, which help her feel confident on packed snow and ice.

“I find they are probably my most favorite and useful piece of winter gear,” said Grinnell, lifting a sneaker to reveal her bling. “I use these for winter hiking and I use them for running and shoveling and pretty much anything else.”

Although she’s been a lifelong runner, Grinnell, who lives in Belmont, Massachusetts, didn’t always embrace the arctic air during her fitness routine.

“I actually kind of worked my way up to that,” said Grinnell, whose other idea of a good time involves volunteering to lead winter hikes with the Appalachian Mountain Club.

“I’m in vacation-mode, so I kind of free-form it,” she said. “I’m out to kind of work off some of the calories. I enjoy it.”

Matt Byrne can be contacted at 791-6303 or at:

mbyrne@pressherald.com

Twitter: MattByrnePPH