Fit Facts: Exercising in the Cold.

By Dorothy Hamburg, M.S., Exercise Physiologist. USA Triathlon Level II Expert Coach, Clinical Exercise Specialist & Health Fitness Instructor (ACSM), and founder of Personal Strength & Training. She is also the owner of TriSportsTraining.com, a site dedicated to women specific triathlon training & coaching.

Snow shoeing, cross-county skiing, hiking in the mountains. Sounds fun. When you�re having fun outside in the cold, it�s important to think about how to keep warm. According to the Center for Disease Control and Prevention (CDC) and the American College of Sports Medicine (ACSM), one of the biggest concerns for people exercising in the cold is hypothermia, abnormally low body temperature due to excessive heat loss. Hypothermia and frostbite, localized freezing of the skin, are common winter health hazards. Surprisingly, dehydration is also a health hazard. So is sunburn. During exercise, your body loses heat several ways: either from sweating (perspiration), breathing (respiration), having the wind blow cold air on you (convection), or sitting on a cold surface (conduction).

What to Watch Out For

Frostbite.

Frostbite occurs at temperatures below 32�F. Wind-chill increases this risk. As a person becomes chilled, his body “thermostat” reduces circulation to the skin to maintain core temperature. The body parts most susceptible are the nose, fingers, cheeks and chin, toes and areas under pressure or wet, such as your heels and feet. Frost-nip, a less severe form of frostbite, usually occurs in high wind or extreme cold, or both. Ordinarily, it is noticed as a sudden blanching or whiteness of the skin. If it is identified early and treatment is taken immediately, no tissue damage should occur. Frost-nip can often be treated effectively by with firm, steady pressure of a warm hand (no rubbing!). Chilled fingertips can be rewarmed by putting them in your armpits or your mouth. As warmth and color returns, there is a tingling sensation. Frostbite involves the skin and the tissue below it. If you suspect you have frostbite, see your physician for immediate treatment.

Hypothermia.

A person who gets cold beyond the shivering stage is in serious trouble. Hypothermia, or subnormal body temperature, can occur from prolonged exposure to temperatures of around 50�F. Changes in weather conditions, air temperature and wind-chill will affect your ability to maintain body temperature. Hypothermia begins with intense shivering. The individual usually complains of tiredness and coldness and is unable to perform complex tasks. When body temperatures fall below 92�F, errors in judgment occur � often accompanied by sluggish thinking and forgetfulness, and slurred speech. Early recognition and prompt action can prevent potentially life-threatening complications. Emergency treatment on the trail includes getting the victim out of the wind if possible, putting on dry hat and gloves, changing wet clothes, putting the victim in a sleeping bag, providing liquids in small quantities, and not allowing him to fall asleep.

Dehydration.

Surprisingly, dehydration is a winter hazard. Sweat may not pour from your brow the way it does during the summer, but depending on your level of exertion and the dryness of the air, significant moisture lost occurs. Fluid intake also drops because people don�t usually crave cold drinks during the winter. Make a conscious effort to drink enough fluids, even when you�re not thirsty.

Sun Damage.

One summer hazard also applies to the winter; sun damage. Sensitive areas such as your ear lobes, neck, the underside of your chin, and your lips are highly susceptible to the sun and the glare of the snow. Reflected ultraviolet rays when combined with harsh, dry wind increases your risk of burning. Always use sunscreen with SPF 30 or above and a lip sun screen.

Dress Warmly and Stay Dry

Clothing is clearly one of the most important factors in helping you maintain body temperature. Clothing�s greatest potential for insulating your body comes from its ability to trap air, a poor conductor of heat. Unlike air, water is a rapid conductor of heat. Even in the coldest of temperatures, people will sweat. Excessive perspiration will increase heat loss, so remove extra layers of clothing whenever you feel too warm. With this in mind you want to: wear clothing in removable layers and choose clothing that can trap air but allow sweat to pass through. Cotton and any tightly woven materials will absorb moisture so it is recommended to not wear these materials. Instead, wearing a base layer of clothing made from synthetic materials such as capilene or polypropylene will transport body moisture away from the skin, keeping you dry and comfortable. A midlayer of clothing made from fleece, wool or a medium weight capilene will provide insulation, trapping body heat and providing warmth. The final layer of clothing should have wind- and weather-resistant properties that fend off precipitation and wind-chill. The same factors that keep your body warm � adequate insulation and keeping dry � will also warm your feet. Applying foot powder and a strong anti-perspirant (not merely a deodorant) to keep your feet dry and comfortable. The right socks are important in keeping your feet warm. A thin liner sock with a wool or synthetic sock worn over it works great. Too many socks or too thick will cut off your circulation causing cold feet. Don�t� forget � wearing a hat and gloves made of the same fabrics will keep you warm and dry, enhancing your performance and comfort while exercising in the cold.

So, layer up and have fun!