Rock Your Outdoor Winter Workouts

You could retreat to the climate control of your gym this winter, but if you brave the same workouts outdoors, science says that you’ll end up with a better body. For starters, you’ll boost your metabolism the minute you step outside: When you exercise in temperatures below 64 degrees, you increase the amount of calories you burn, according to a study at Maastricht University in the Netherlands. That’s because chilly temps trigger something called nonshivering thermogenesis. This means that your body isn’t so cold that it’s shivering, but behind the scenes, it’s stoking the metabolism fire to keep you warm.

You’ll also torch more fat. Several studies point to the effect of cold on brown adipose tissue (brown fat), whose main job is to keep you warm. Expose your body to cold, and you’ll activate brown fat, which changes unhealthy white fat that collects around your belly, butt and hips into beige fat, allowing it to burn calories for heat.

“For most exercise situations, cold is safer and more accommodating than the summer’s heat,” explains Bill Brewer, the director of exercise science at the Rochester Institute of Technology in New York. “And it lets people work harder and longer.”

Here’s how to keep comfortable so you can focus on getting a killer workout.

Factor in the wind and the wet.

Did a quick temperature check before heading out? Now double-check the forecast for the windchill and the chance of rain. Forty degrees may not sound so cold, but when you add wind and moisture, it can be frigid—and require either more layers or a shorter jaunt. According to the National Weather Service, frostbite can even develop when skin is exposed to 40-degree temperatures if there are 20-mile-per-hour winds for 30 minutes. 

Layer up—but don’t overdo it.

You may be tempted to throw on your heaviest fleece for that outdoor run, but it’s better to wear several thin layers, says Cedric X. Bryant, Ph.D., the chief science officer for the American Council on Exercise. “You’ll trap and warm the air between each layer for an insulating effect,” he says. The outer layer should repel wind and precipitation, while the inner layers should provide warmth. For inner layers, stick with sweat-wicking fabrics like polyester and wool instead of cotton, which soaks up moisture. “Your body loses heat four times faster when exposed to water,” Bryant says; this can rapidly lead to hypothermia. As you warm up, you can fine-tune your comfort level by peeling off layers.

Put a lid on it.

“Old research cited that heat loss through the head amounted to almost half of your body heat,” says Charles Pelitera, an assistant professor of kinesiology and the coordinator of health and wellness at Canisius College in Buffalo. “Although recent studies peg it at only about 10 percent, the reality is that any area of the body that is exposed is going to lose heat at a greater rate, so be sure to cover up.” A hat, a scarf, a neck gaiter and gloves can make a big difference.

Bring a hot-water bottle.

Consider filling your water bottle with water that’s about hot-coffee temperature. “Holding the bottle can keep your hands warm, and consuming the heated water helps maintain your internal temperature,” Brewer says. This also makes your bottle less likely to freeze on the coldest days.

Avoid overheating.

Many avid runners like to use hand-warming packets or stick-on heating pads, which warm you instantly, during winter workouts. But experts caution: Don’t put artificial warmers in places where air doesn’t circulate, like your shoes. “They will cause your feet to sweat prematurely, and because the sweat is not able to evaporate, it will cool your feet and actually make them colder,” Pelitera warns.

Remove sweaty clothes ASAP.

“Strip down completely and change your clothes, including your undergarments,” Pelitera says. “Sweat underneath your workout clothes will cause you to become cold at a much quicker rate.”

Know when it’s too cold to exercise safely.

With proper gear and adjustments, you can work out in subfreezing temps. The danger of frostbite and hypothermia is highest when the temperature is below 10 degrees and the wind is above 5 miles per hour. (Check the National Weather Service’s windchill chart at nws.noaa.gov to see your chance of frostbite.) Early signs of hypothermia are weakness, shivering, slurred speech, dizziness and confusion, notes Bryant. If you have any of those, get to a warm area for first aid fast.