Sure, it is freezing outside. But before you retreat to the treadmill for your run, consider this: Chilly temperatures may change unwanted fat into a different kind of fat that actually burns calories.
Huh? Think of it this way: The fat in your body isn't equal. There's white, brown, and shades in between. White fat is what we commonly think of when we think of unwanted body fat. Brown fat is metabolic tissue that actually burns calories. There's a growing body of scientific literature—the most recent being a mouse study published in Molecular Cell—that suggests exposing our bodies to cold temperatures turns our white fat to brown.
That means heading outside for a winter run could not only help you burn calories, it could change your body composition. Just remember these tips when running in the cold:
Don't expect to set a new PR. "Your performance in the cold can start to decrease as the temperature drops below 40 degrees," says Sean M. Wells, DPT, ATC/L, CSCS, and fitness expert at bistroMD. "Peripheral blood vessels constrict, joints feel stiffer, and muscles are harder to warm up."
Make sure to warm up. March in place, do jumping jacks, or hop for five minutes to get your heart pumping blood to your muscles. "This will ensure you don't strain a muscle or injure your joints," says Wells.
Dress appropriately. Layer, layer, layer. "Wearing loose, light layers helps trap warm air," suggests Amy J. Derick, MD, clinical instructor of dermatology at Northwestern University in Illinois. "The first layer should be made of a synthetic material, which wicks moisture away from your body," she says. "The next layer should be insulating (wool and fleece are good insulators and hold in more body heat than cotton), and the top layer should be windproof and waterproof."
Cover your extremities. "The biggest concern with exercising outdoors in the winter is the risk of frostbite," says Wells. Make sure you cover your hands and ears, and turn around if your skin starts to sting or feel numb (especially the skin on your nose and chin, areas that are more difficult to cover).
Practice slip prevention. Frigid temperatures and precipitation can make for icy paths and sidewalks. Luckily there are a few things you can do to make sure you stay steady on your feet, says Mike Ross, author of The Balance Manual and exercise physiologist at Gottlieb Center for Fitness, part of the Loyola University Health System. First, check the treads on your shoes. If they're worn down, your running shoes won't give you the traction you need. Second, have a plan. Think about what would happen if you fell anywhere on your route. Could you get help? If not, map out a safer alternative and make sure to take your cell phone. Finally, slow down. Trying to go your normal pace when it's icy out pushes your sense of balance.