Winter months can still be time for physical activity

Winter is here. The temperature is dropping, and the wind is gaining speed. These factors might encourage one to say, "I think I'll take a break from my physical activity and begin exercising again when spring arrives." You don't have to stop exercising during the winter months, however. Read on-with a little effort and some "cold" knowledge, you too can enjoy the benefits of regular exercise during the colder months.

In contrast to hot and humid conditions, exercising in the cold usually does not threaten one's health. Clothing for heat conservation can be selected, and exercise itself increases the production of body heat. Nevertheless, there are several cold-related injuries and techniques the American College of Sports Medicine Resource Manual recommends that you be familiar with to increase the likelihood of your enjoying a safe cold weather exercise session.

Wind velocity (wind-chill effect) is a major factor in the severity of cold stress on unclothed skin or skin covered by wet clothing because it markedly increases heat loss by convection and evaporation. For example, exercising at a temperature of 25 degrees Fahrenheit with adequate clothing is not too cold, but if the wind is blowing at 25 miles per hour, the chill factor lowers the actual temperature to -5 F. This effect is even worse if a person is wet and exhausted. Adequate protective clothing is very important in preventing cold injuries during exercise. Windproof and water-repellent (not water-tight) outer garments are necessary when wind and precipitation are present. Increased insulation under the protective outer garments is best achieved with layers of loose fitting clothing. If possible, the garment closest to the skin should be material that will "wick" moisture away from the skin and prevent excessive accumulation of sweat and minimize evaporative cooling.

Inhalation of cold air usually does not cause tissue damage in the respiratory tract, although it may be uncomfortable. This is because the respiratory system is efficient in warming and humidifying the air. However, special consideration should be made for persons with exercise-induced asthma and coronary artery disease.

Frostbite is a danger that is associated with cold weather, but it can be avoided. With freezing temperatures and windy conditions, frostbite can occur within minutes on your hands, nose, ears and toes. Be sure these areas are covered with clothing during extremely cold weather.

Below is a list of preventive techniques recommended to reduce the likelihood of cold related injuries and/or discomfort.

* Listen to weather reports noting temperature and wind-chill factor. Unless the equivalent temperature is in the "little danger" range, avoid outside exercise.

* Warm up carefully until sweating is evident.

* Use two or three layers of lighter-weight clothing rather than one heavy warm-up suit since warm air will be trapped between the layers of clothes, enabling greater heat conservation.

* Protect the head (warm hat), ears, fingers, toes and nose.

* Never use rubberized, airtight suits that keep sweat in. When the body cools, the sweat starts to freeze.

* Keep clothing dry and change wet items as soon as possible.

* Dehydration can be a problem when exercising in cold weather. Your body loses fluids more quickly than you realize. Drink cool water freely before, during and after exercise.

* If you are a runner, plan your jogging course to include a series of loops rather than a long run out and back.

* If wind is present, it is best to run first into the wind and return with the wind at the back, since running into a head wind with wet clothes will draw heat away from your body.

There are many benefits to regular exercise. Following these guidelines will allow you to maintain physical levels throughout the cold months ahead.

Jill E. Welkley is an assistant professor in the Department of Health and Physical Education.