It certainly seems like we have had a colder winter than normal for eastern North Carolina. However, that does not mean that you have to skip your exercise routine. Exercising in cold weather can help shake those winter blues, improve your energy level, and ensure that you will be in better shape once swimsuit season arrives. Like most things, there are a few precautions that you should take when exercising in the cold. These involve the use of appropriate clothing, a proper warm-up routine, and knowledge of cold-related injury risks.

Prior to leaving the house, you should always make sure that you are wearing appropriate clothing for cold weather. According to the American College of Sports Medicine, typical cold-weather clothing consists of three layers: an inner layer (lightweight polyester or polypropylene), a middle layer (polyester fleece or wool), and an outer layer (Gortex). The inner layer should remain in direct contact with the skin and wick moisture to the outer layers where it can evaporate. The middle layer provides the most insulation, while the outer layer repels wind and rain and allows moisture transfer to the air. It is important to have layers so that one can be removed while warming up. The outer layer generally should not be worn during exercise but should be worn during periods of rest.

The warm-up helps in both the mental and physical preparation for exercise while reducing the chance of injury. When warming up in colder temperatures, keep in mind that muscles take longer to stretch. Therefore, your warm-up should accommodate this by being longer in duration. The FITT principle (frequency, intensity, time, and type) is a good guide to follow when performing warm-up routines:

Frequency: warm-up routines should be done before any exercise session or physical activity.

Intensity: exercises of low intensity should be started first with a progressive increase in intensity to match that of the main exercises of the workout.

Time: warm-up routines should last at least 5-10 minutes with slightly longer duration in cold weather.

Type: a variety of different exercises can be selected (there is no wrong exercise as long as it increases your heart rate and breathing while involving the specific target muscles of the main exercise).

 

 

Just as important as proper clothing and warm-up routines, an appreciation of the risks of cold-related injuries is necessary. Hypothermia, frostbite, and cold-induced bronchoconstriction represent the most common cold-related injuries.  Hypothermia occurs when the body’s core temperature drops below 35°C. At this temperature, loss of heat exceeds heat production resulting in a net loss of heat.  Extreme sensations of cold, shivering, and even apathy with social withdrawal are warning signs. Once the temperature falls below 0°C frostbite can occur. It is most commonly seen on exposed skin (ears, nose, cheeks, and wrists) as well as the hands and feet. Finally, exercise-induced bronchoconstriction is a potential risk. This occurs in approximately 4 percent to 20 percent of the general population and 80 percent of those with asthma. It is identified as a temporary narrowing of the airways caused by exercise. Cold exposure can trigger bronchoconstriction and asthma-like symptoms. One way to decrease the likelihood of EIB is to breathe through your nose while wearing a scarf to warm the air as it travels down to your lungs.

 

Body size and age also play a part in how individuals react to extreme temperatures. Larger individuals (those with high combined values of thickness of subcutaneous fat, percentage of fat, and muscle mass) tend to maintain core temperature better than those with less fat and muscle. Individuals aged 60 years and older are often less cold tolerant than younger individuals, due to reduced vasoconstriction (the narrowing of the blood vessels resulting from contraction of their muscular wall). Older individuals also have blunted thermal sensitivity and cannot sense changes in temperature as quickly. These same principles apply to children too, as their small size and lower amounts of subcutaneous fat reduce core temperatures much quicker than those of adults. Therefore, children and adults older than 60 years of age are both at higher risk of hypothermia.

With these tidbits in mind, cold weather is no longer an excuse to discontinue your regular exercise routine. Wearing layers that can be removed as your body warms up, taking extra time to complete your warm-up routine, and maintaining an awareness of potential cold-related injuries will help make your winter workout a pleasure.

 

Judy Van Dorp, RN, ACSM, is the manager of Lifestyles Medical Fitness Center in Washington.