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?

Heat loss is controlled in two ways: 1) insulation _ body fat plus clothing; and 2) environmental factors _ temperature, wind and whether you're exercising in the air or in the water. Each of these factors plays a role in the body's ability to maintain a comfortable temperature during exercise.

Insulation - Although many people aspire to have a lean figure, people with a little more body fat are better insulated and will lose less heat. Clothing adds to the insulation barrier and is clearly the most important element in performance and comfort while exercising in the cold. One study showed that heat loss from the head alone was about 50 percent at the freezing mark, and by simply wearing a warm hat subjects were able to stay outside indefinitely.

Clothing is generally a good insulator because it has the ability to trap air, a poor conductor of heat. If the air trapped by the clothing cannot conduct the heat away from the body, temperature will be maintained.

Unlike air, water is a rapid conductor of heat. Even in the coldest of temperatures, people will sweat and risk significant heat loss. With this in mind you want to choose clothing that can trap air but allow sweat to pass through. By wearing clothing in layers, you have the ability to change the amount of insulation that is needed. Many new products can provide such a layered barrier; however, it is important to avoid heavy cotton sweats or tightly woven material that will absorb and maintain water. These materials cannot provide a layer of dry air near the skin.

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 centre 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 (.5EC above normal). So, to keep your feet warm you must also keep the rest of your body warm at all times

Rules For Exercising In The Cold

• Check the temperature and wind conditions before you go out.

•  Keep your head, hands and feet warm.

Dress in layers that can provide a trapped layer of dry air near the skin (avoid cotton sweats and other similar materials).

• Warm the air you are breathing if temperatures are below your comfort level (usually around - 20EC ).

Cold weather MYTH - Going out with wet hair in winter is a sure way to catch a cold.

Fact: Wet hair won’t make you catch cold, nor will wet feet, wet clothing or drafts. You’ll certainly feel chilled faster if you go out with wet hair, but you won’t be more susceptible to rhinoviruses, which are the real cause of colds. In one experiment after another, subjects have been exposed to bone-chilling temperatures, icy baths, and drafts, with or without wet feet or wet hair. They catch cold only when exposed to viruses in just the right way, and those who aren’t exposed to the viruses don’t catch colds, no matter how chilled and wet they are. In cold weather, you’ll be more comfortable, obviously, if you stay dry and out of icy drafts – but you can still catch a cold if you are exposed to a virus to which you are not immune.