1/14/2010
Written By: Marc A. Molis, MD, FAAFP, Sports Medicine of Iowa
Category: Health & Fitness  

As the weather turns colder and the snow starts to fall, I thought it appropriate to write about how to safely exercise in the cold weather.  Moving indoors to exercise and train is an option for some people, but for those athletes who don’t mind the cold weather, or those whose sports depend on the snow and cold weather, staying warm and safe is a priority. 

There are two basic ways to keep warm:  increased heat production and decreasing heat loss.  Increased heat production is the least effective way to prevent cold illness, but is still important.  Exercise and shivering increase heat production.  Eating more frequent meals to help replenish fuel stores can help as well, especially for athletes who are doing prolonged exercise in cold weather.  Also, remember to stay well hydrated.  Dehydration can impair blood flow. 

Decreasing heat loss is the most effective way to prevent cold injuries, and this is mainly accomplished with “layering” of clothing.  Insulation (to prevent heat loss) and permeability (to allow moisture to escape) are important properties of cold weather clothing.  Most versatile cold weather clothing is composed of 3 layers.  The inner layer closet to the body should be a hybrid polyester fabric (e.g. Coolmax, Thermolite, and Thermax) that allows wicking of moisture away from the body.  Avoid cotton clothing as the first layer.  The middle layer can be another layer of the first fabric, or a heavier layer such as wool, synthetic blends, fleece, or down.  This layer can often cause overheating, though, so modify this layer depending on the type of activity. 

The last layer is the protective shell, and this should be windproof and water repellant.  Some newer nylons allow a lot of breathability, allowing moisture and sweat from the athlete to pass outward and evaporate.  The goal of layering is to stay warm without overheating. Other tips that can help include wearing mittens instead of gloves, wearing an insulating cap or using a hood when needed, and using ski goggles to prevent eye/corneal freezing.  Wearing a scarf, neck gaiter, or balaclava can help prevent neck and face exposure.  Scarves can also help to warm the air, and are suggested for those athletes that have a history of asthma (the cold, dry air often makes asthma symptoms worse). 

Whether you are involved in a sport like skiing or snowmobiling, or just like to be outside for exercise or fun, following the above tips can help keep you safe.  If you do have difficulties with exercising in the cold, or sustain a cold injury, see a doctor who is experienced in sports medicine to help you.