It is important to properly prepare for an outdoor workout in order to limit the risk of cold injury.

Exercising in the cold weather

By Elizabeth C. Gardner, MD

With the CDC encouraging us to exercise outside in order to limit the potential spread of COVID-19, many people in northern climates are finding themselves sweating outside in the cold of winter. For those who would typically spend their winter months in the gym, it is important to properly prepare for an outdoor workout in order to limit the risk of cold injury.


Hypothermia Frostbite


Hypothermia is a reduction of the body’s core temperature below 35C (95F). As the body’s temperature decreases, vital processes slow and may eventually stop working. Signs of hypothermia include shivering (or lack of shivering in later stages), decreased coordination such as difficulties walking, drowsiness and impaired judgement.


Frostbite is a freezing of the skin and superficial tissues. This most commonly affects exposed areas like the ears, fingers, toes, nose and cheeks, although even the cornea (the covering of the front of the eye) can be affected when skiing or snowboarding. Prior to the damage of frostbite, the skin may become numb or feel prickly. Once frostbite occurs, the skin may appear pale yellow or blue, have complete numbness and the tissue may feel firm and frozen.


When considering the risk for cold injury such as hypothermia or frostbite, it is important not only to consider the temperature outside, but also the duration of exposure as well as wind chill index and humidity.


Clothing

Exercise clothing is not just about looks and performance, especially when it is cold outside. It is an important defense against the dangers of the cold. In cold weather, there are three important clothing layers: a wicking layer, an insulating layer and a shell later. The deepest layer should be a thin wicking layer to pull moisture from sweat away from the skin. The insulating layer is next – its role is to keep warm air near the body for warmth. Cotton is not a good insulator when it is wet, as may happen during a vigorous workout. So synthetic fleece or wool are better options. Finally, the outer shell layer protects the body from wind and external sources of moisture, while allowing some of the internal moisture to escape. Hats or headbands are important to manage heat loss and protect against frostbite. Similarly, dry gloves are a must, as frostbite of the peripheral tissues can occur even if the body’s core temperature is normal.


Sunscreen


It is important to remember that even in the cold, it is still possible to get sunburned. The risk increases when there is surrounding snow, which can reflect the sunlight. Therefore, it is important to wear a sunscreen that blocks both UVA and UVB rays, and to remember to apply a lip balm with sunscreen
too.

Hydration


Hydration remains crucial when exercising in the cold. In addition to the fluid lost through typical sweat, there can be an increase in the fluid lost from respiration and urine production in the cold. Cold temperatures also can blunt the sensation of thirst, making remembering to drink more difficult. There are many benefits to exercising outside in the winter, especially during the pandemic. With proper preparation and consideration, it can be safe and enjoyable to exercise as the temperatures
drop.

References:
Carlson, MM. Exercising in the Cold. ACSM’s Health & Fitness Journal. 2012;16(1):8-12.
Castellani JW, Young AJ, Ducharme MB, Giesbrecht GG, Glickman E, Sallis RE. Prevention of cold
injuries during exercise. Med Sci Sports Exerc. 2006;38(11):2014-22.
Fudge, J. Exercising in the Cold: Preventing and Managing Hypothermia and Frostbite Injury. Sports
Health. 2016;8(2):133-139.