The biggest concern for exercising in the cold is hypothermia, or too much heat loss. When you exercise in a cold environment you must consider one primary factor: How much heat will your body lose during exercise?

Layer Up for a Warm Workout

Clothing adds to the insulation barrier and is clearly the most important element in performance and comfort while exercising in the cold. Generally, heat loss from the head alone is about 50 percent at the freezing mark, and by simply wearing a helmet or hat, a person can stay outside indefinitely. By wearing clothing in layers, you have the ability to change the amount of insulation that is needed. While many new products can provide such a layered barrier, it is important to avoid heavy cotton sweats or tightly woven material that will absorb and retain water.

Don’t Leave the House Without Your Gloves

Keeping the hands and feet warm is a common concern when exercising in the cold. Lower temperatures cause blood to be shunted away from the hands and feet to the center of the body to keep the internal organs warm and protected. Superficial warming of the hands will return blood flow to prevent tissue damage. Blood flow will not return to the feet unless the temperature of the torso is normal or slightly higher (0.5 to 1.0 degree Fahrenheit (F) above normal). So, to keep your feet warm you must also keep the rest of your body warm at all times.

Check with the Weatherman

Always check the air temperature and wind chill factor before exercising in the cold. Data from the National Safety Council suggest little danger to individuals with properly clothed skin exposed at 20° F, even with a 30 mph wind. A danger does exist for individuals with exposed skin when the wind-chill factor (a combined effect of temperature and wind) falls below -20° F.  If you are exercising near the danger zone for skin exposure, it also is advisable to warm the air being inhaled by wearing a scarf or mask over your nose and mouth.

On the days it is too cold to exercise outdoors, check out ACE’s www.acefitness.org/exerciselibrary/default.aspx for great workouts that can be done anywhere. For more information about the American Council on Exercise go to: www.acefitness.org.

Editor's Note: I’ve come across some good stuff called Polar Max (www.polarmax.com) that is the right stuff for the first two layers in a layering system. The PolarMax base layer — the one next to your skin —comes in three ‘weights’ (warm, warmer and warmest), has a proprietary wicking material called Acclimate, and is lightweight, comfortable and offers four-way stretch. And, it’s made in the USA. These attributes apply to the fleece layer, which is the next in the layering. The object for this — or any other layering system material — is for the base layer to get the moisture off your skin and onto the surface of the first layer (called wicking) and then it’s supposed to wick through the fleece layer to evaporate out in the air. This stuff works for real. Figure about $150 for Acclimate bottoms, tops and fleece top (MSRP is $49.95 each for the “warmest” weights).