Cold weather doesn't mean the game is off. Just that you should make a few minor adjustments.

By Kevin Foley

It's a typical December in the Colorado Rockies: A 50-inch snow base has accumulated in the mountains, and Mark Macy, three-time winner of Alaska's 100-mile Iditashoe snowshoe race, is hitting his prime training season, even though the daybreak temperature regularly dips well below zero. "Cold is part of life," says the Evergreen, Colorado—based ultrarunner. "You can't stay inside and kick back just because it's below freezing outside." When winter is at its most brutal, Macy actually boosts his training. He runs and snowshoes through whiteouts and screaming winds and admits that it's painful, lonely—and profoundly satisfying. "I'm not nuts," he argues. "I don't want to get out of my warm bed and go running when it's minus 25 out. But I always do, and I never regret it."

Putting aside the issue of Macy's sanity, there's no question that staying fit through winter presents athletes with greater challenges than simply figuring out how many layers to wear. From cold-induced asthma to a higher frequency of muscle strains, winter changes the game of how to train. Spend some time mastering the season's peculiar subtleties, though, and you'll soon enjoy Macy-style peak experiences. "It's 40 below including windchill, I'm running in the mountains, and the wind is blowing snow so hard I can barely see," he says, sharing the sort of moment that he cherishes. "I love that."

Don't worry. As one of a number of winter experts we've handpicked to help you bust through the bleak months, Macy won't be forcing you to stumble blindly through mountain blizzards. But heed his words as well as the other advice on the pages that follow, and come spring you won't regret it.