1. Winter hikes scorch calories.
People who hiked in temperatures of 15 to 23 degrees burned 34 percent more calories than those who hiked in comfortable mid-50s weather, a study from the University at Albany in New York found. The reason? In part, it comes down to temperature—in cold weather, your body burns extra energy just to keep your internal furnace roaring. But the second factor is terrain. “Trudging through the snow adds extra resistance,” says Vincent.
2. Plus, you’ll build muscle.
In a study in the American Journal of Human Biology, researchers observed people during a three- to four-month outdoor training program in cold climates. Women increased their muscle mass, even while burning more calories than they consumed, unlike the male subjects. “The women were better able to manage the cold than men because they have more body fat and could use those fat stores to fuel the activity,” says study author Cara Ocobock, Ph.D. That is, their bodies were less likely to break down muscle for fuel—allowing for the muscle gain as they lost six pounds of fat on average.