Chances are you've seen them, running through the snowflakes, striding along sand-strewn streets and dodging icy patches of pavement.
Forcing oneself to train for a marathon, despite all the other pushes and pulls of life -- work, family, friends, aching muscles and creaking joints -- is unquestionably hard, even for those who love to run.
But to do it when that means running in a snowstorm? Now that is commitment.
"If it's light I'll run through it," Joe O'Connor, 53, said. "I've run a few races in snowstorms. But there were a few snowstorms that the driveway had a few feet of snow in it, and I had to clear the driveway before I could even get out on the road."
Mother Nature has not been kind to many of the 4,814 Massachusetts entrants training for the 2013 Boston Marathon. There have been biting headwinds, freezing temperatures and, of course, record snowfall totals across much of the state.
In fact, Worcester was the nation's snowiest city (among cities with a population of more than 100,000) in 2012-13 with 108.9 inches of snow, according to the National Weather Service. Syracuse, N.Y., was second, with 96.5 inches.
Yet the work that goes into putting on the show must go on.
For some, like Bob Barry, the rough winter of 2012-13 meant bringing the workouts indoors to the treadmill (or "dreadmill," as Barry and others called it) or signing up for a spinning class to augment traditional training. For others, like Kimberlee McCarthy, that's simply not an option.
"I really don't run on the treadmill," McCarthy said. "I've walked on the treadmill but I've never run on the treadmill.
"For the most part I just went out and ran whatever the conditions were."
McCarthy said she used "grippers" for her shoes when it was particularly icy, but even those she didn't want to overuse for fear of it affecting her gait. Mostly, she just dealt with the elements as she ran her routes through the Newton Square section of Worcester.
"I'm not one to risk not being trained enough," she said. "I don't want to risk injury."
So McCarthy continued to take to the streets, doing so literally when she found the sidewalks still covered in snow. That led to a few angry exchanges with annoyed motorists.
When he's been able to get outside for his training, Barry has also kept his eyes on the road. But the 61-year-old does so for a different reason.
"I'm very concerned about people texting and on the cellphone [while driving]," Barry said. "Those have sometimes been a close call. You have to stay aware of who's coming at you -- you can see they're texting and drifting."
And here you thought black ice was a problem for runners.
For Matt Wamback, a first-time Boston Marathon participant, the stormy weather meant more planning.
"Maybe I'm lucky," he wrote in an e-mail. "I am definitely a fair-weather runner, so this winter was a good test for me mentally and physically. The snow didn't bother me so much, I was able to change up my long runs on Sunday to either Saturday or Monday (seemed like most of our storms fell on the weekend).
"The cold and the wind really got to me, though, and some of those cold days I was forced onto the treadmill for what seemed like hours but in reality was only 45 minutes to an hour."
Wamback said that on some runs he got so cold his water and Gu energy gel started to freeze. His cellphone stopped working, too.
"You know it's cold when that stuff happens," he said.
As the temperatures have edged back above freezing, runners have started to taper their training. The race is almost here.
O'Connor, who works in IT strategy for a company in Westminster, Mass., said the winter of 2012-13 was even worse because of the memories of the winter of 2011-12. That season was so mild, O'Connor said, that one day while on a training run near work he decided to take a nap on a park bench in his singlet and shorts.
"That's something I wouldn't even try now," he said.
Of course, New England being New England, there's no predicting Marathon Monday weather. After a mild winter training for the 116th Boston, runners were surprised with temperatures in the mid-80s on race day.
The heat was too much for Barry to take last year.
"I made it to just before Mile 18, and then I made the wiser decision [to drop out and live] for another day," he said. "It was a terrible day. I would never train in a day like that.
"So I'm looking forward to this year and hopefully the weather will cooperate."
Even if it hasn't cooperated all winter long.
Jack McCluskey is an editor for ESPN.com and a frequent contributor to ESPNBoston.com.