1. Dress ‘Dry,’ Not Just ‘Warm’
The quickest way to lose body heat is to get wet. Because water is an efficient heat conductor — moving heat away from the area of highest concentration (your body) to the lowest (cold air outside) — being wet will quickly leave you chilled and miserable. If you’re cold and wet you may be more inclined to cut your workout short, and you’ll also increase your risk of hypothermia (when your core body temperature falls below 95 degrees Fahrenheit) or, in freezing conditions, of getting frostbite, Ridings says.
“Wet fabric next to your skin will zap your body heat and give you an unwanted chill,” says Jeff Galloway, a former Olympic runner and the author of Running: Getting Started (and other running training books and programs).
That means, skip active wear made of cotton, which soaks up sweat and rain and holds in moisture. He recommends opting for synthetic fibers instead, such as polyester, nylon, and polypropylene designed to dry quickly. “They wick away moisture about 50 percent faster than cotton,” Galloway says.
2. Layer Up
Don’t stop at sweat-wicking clothes. You also need layers to trap warm air next to your body and keep out the elements (like rain, snow, and wind), says Brian Calkins, an American Council on Exercise (ACE)–certified personal trainer and the president of HealthStyle Fitness in Cincinnati.
Here’s how to layer up for winter workouts: First, put on a thin base layer made of synthetic fabrics (discussed above) to help pull sweat away from your skin. If it’s really cold outside, wear a middle layer, such as polar fleece, for extra warmth. Then, add an outer layer (or shell) to protect you from wind, snow, and rain.
Depending on the weather, your outer shell can be a lightweight nylon windbreaker or vest, or a heavyweight, waterproof jacket. Note that the more water-repellent the shell, the less it will allow moisture from the inside (your sweat) to escape, even if you’re wearing the proper base layer.