The cold air burns your face and lungs. Cars spray slush all over you. You slip and slide as snow and ice make paths treacherous. There's no question that winter weather can be a deterrent to a consistent running program, but the biggest obstacle is often psychological: just getting out the door. After all, it's dark before and after work. Excuses come easy when it's cold and bleak, and one lost run turns into several. It's enough to make some of us hang up our running shoes until spring arrives.

So how cold is too cold to run? That depends on you. The weather often isn't as bad as it looks; you can run fairly comfortably in near-blizzard conditions. Maintaining a positive attitude is the key to success—think of cold weather as a challenge to be overcome. You don't have to be all that tough to run in the cold, you just have to be prepared and use common sense.


Dress—and undress—properly

Dress to stay warm but not too warm. The underdressed runner is vulnerable to hypothermia and frostbite. Overdressing can be risky too—excessive sweating can ruin the insulating abilities of your clothes. A good rule of thumb is to dress as though it were 20 degrees warmer out than it really is. You should feel a little chilly when first going outside but warm up within five minutes on the run.

The secret to maximum comfort is dressing in layers to trap body heat: Wear an inner wicking layer, an insulating middle layer, and an outer windbreaking layer. The inner wicking layer (a snug-fitting sport top and tights) should be made of a breathable fabric like polypropylene or Coolmax rather than an absorbent fabric like cotton, which will get wet and soggy. The middle layer (a long-sleeve wool or fleece shirt) should fit loosely. The outer layer (jacket and pants) should protect you from wind, rain, and snow. Gore-Tex is a good choice for cold, wet weather, but you may get too hot if you're running hard or long—it's not breathable. In milder weather (or if you're planning a long or hard run), you'll be better off with a breathable, water-repellent, and windproof fabric. Make sure your outerwear has zippers so you can make adjustments while you're out. Some days you won't need three layers; other days, conditions will be so fierce, you'll need four layers. In really cold weather, try moisture-wicking wind briefs, which have a nylon front panel to protect your privates from the cold.

Also, be sure to protect your extremities—toes, fingers, ears, and face—from discomfort and frostbite. Always bring along a hat and gloves or mittens, even if you don't need them when you start your run. Mittens will keep you warmer than gloves. In extreme weather, double up: Pair polypropylene or Thermax gloves with fleece or Gore-Tex mittens and wear a thin pair of socks made from a wicking material (no cotton) plus an insulating outer sock made of acrylic and wool. Cover your nose with a face mask or balaclava.

During a run, conditions may change several times, requiring you to peel off layers as you warm up or add clothes as you get chilled. Don't toss away articles of clothing unless you're positive you won't need them again. Tuck small items into your jacket pocket or waistband. Larger items can be tied around your waist. The first item to remove is your hat, then your gloves. Unzip or remove your outer jacket if you start to overheat. As you cool, replace the clothing in reverse order.


Fight the Wind-chill Factor

Avoid the bitter cold and the dark. Schedule runs when the sun is at its warmest instead of running in the early morning and late evening, when temperatures are lowest.

Notice the wind as you set out: A cold headwind is a serious enemy. When running an out-and-back course, begin by running into the wind, when you are full of energy and prepared to face this obstacle. (Starting out with the wind at your back allows you to build up a good sweat—which will make you wet, cold, uncomfortable, and prone to frostbite on your return trip.) Try to find a course that's sheltered from the wind on cold, blustery days.


Warm Up and Cool Down

A proper warm-up is even more important in winter because exposure to cold stiffens muscles and joints. Starting a run too fast on cold days could result in muscle strain or respiratory problems. Try warming up indoors by walking on a treadmill or riding an exercise bike for 5 to 10 minutes. If this isn't possible, start with a brisk walk or a slow jog to gradually adjust to cold conditions.

End runs with a slow jog or brisk walk. Don't stay outside for too long after you've slowed the pace. Go inside and change into dry clothes immediately after finishing to prevent hypothermia.


Take Two

Not only will running with a friend keep you motivated—you're more likely to get out the door if you know someone is waiting for you at the end of the street—but it's an important safety precaution when it's cold and dark. A partner can get help if you fall or are overcome by the temperatures. Don't run alone in very cold or slippery weather, especially off the beaten path. No partner? Make sure someone knows your course and estimated return time—a good precaution at any time of the year.


Change Your Pace

Don't pay too much attention to your training pace on very cold days. Just go fast enough to keep warm and concentrate more on your perceived exertion rather than pace per mile.


Go the (Shorter) Distance

Shorten runs on excessively cold days for comfort and safety. The longer you are out there, the greater your exposure to the elements and risk of cold injury. Most runners can put up with cold conditions for at least a half hour before getting too uncomfortable.


Dashing Through the Snow

A light layer of snow provides good cushioning and reasonable traction. But after it gets packed down and becomes icy and crusty, it becomes treacherous. Slipping and sliding on snow or ice can sabotage your form and cause you to tense up and use muscles abnormally, putting you at risk for injury. Many runners have fallen on the ice while running and ended up with broken bones and bruises that cost them weeks of training.

Walk around icy areas. Be especially careful on downhills and turns and when running after dark. If you find yourself running over slippery paths, slow the pace, shorten your stride, and try to run flat-footed with a low knee lift. Just shuffle along, maintaining good balance. Stay relaxed. Better yet, avoid the problem by sticking to running paths that are clear of ice.

For more traction, you can try using "ice joggers," which are like old-fashioned galoshes but have small spikes on the bottom. Just slip them over running shoes for a good grip on snow and ice. Or strap on snowshoes made for runners. They provide plenty of cushioning and traction and make the workout that much harder—and more fun.


Avoid Traffic

If it's snowing, your vision (and that of motorists) will be impaired. Don't share the road with cars under snowy or icy conditions. When the snow covers your favorite courses, switch to roads, sidewalks, or trails that are well-plowed and have minimal or, better yet, no car traffic. This may mean running loops around a parking lot or residential area.


Stay Inside

According to the National Weather Service, wind chills of as low as -20°F present little danger for the properly clothed person. But don't let that give you a false sense of security; if you're out in below-zero weather, you must dress warmly, keep dry and stay moving or risk frostbite and hypothermia. No one will blame you for running indoors on a treadmill when it's icy or below freezing. Just make sure you get on the treadmill and not the couch! Or cross-train: Rather than letting motivation sag during the winter, why not cut the running by 10 to 50 percent and replace those training minutes with biking, swimming, or time on the various aerobic machines. Outside, head for snow-covered trails on cross-country skis. And finally, try to run at least three times a week so your return to running is fairly comfortable.