Cold Weather Running
Adequate awareness and precautions are important for the full enjoyment of cold weather running. Frostbite and hypothermia are the most common hurdles that one may come across in cold weather running. Knowing the risk factors and warning signs of frostbite and hypothermia are the first step to prevent such injuries.
What is frostbite?
Frostbite occurs when skin temperature drops below -0.5°C resulting in freezing injury to peripheral tissues. Common areas are that are away from the body’ core and are more susceptible to less blood flow such as the nose, ear, fingers, and toes. Feeling of skin numbness, pale skin or ice crystals on the surface of the skin is indicative of probable frostbite. While a superficial frostbite injury may only result in minimal tissue loss a deep frostbite can result in extensive tissue loss. Feeling of pain as skin temperature falls below 20°C and numbness as skin temperature falls below 10°C are warning signs that can alert potential frostbite injury.
What is Hypothermia?
Hypothermia occurs when our physiologic heat production fails and our core body temperature falls below 35°C (95°F). A mild hypothermia can be recognized by increased shivering, social withdrawal, and other behavior changes but often symptoms can vary from person to person. Sever hypothermia would result in losing the ability to shiver, confusion, and ultimately loss of consciousness. Shivering is the normal response of the body that can increase our metabolic rate by as much as 5-6 times to fight a lowering core temperature. Shivering requires proper fuel and energy stores in the body.
Strategies prevent Frostbite and Hypothermia
Know the risk factors:
- Avoid wet, windy and snowy conditions when possible. These would increase the rate of heat loss.
- Always take advice from your medical practitioner when you have an underlying medical condition (Hypoglycemia, various endocrine abnormalities, circulatory and lung conditions).
Know the early warning signs:
- Frostbite: Feeling of pain, skin numbness, pale skin or ice crystals on the surface of the skin.
- Hypothermia: increased shivering, confusion and other behavior changes.
Clothing:
A layered approach to clothing is the best way to prevent injury and respond to weather changes. Each person would require different layers depending on their heat production and the running conditions.
- Innermost layer: Should be able to wick moisture away from the skin and transfer to outer layers of clothing. Good choices are polypropylene, polyester, and synthetic wool. Avoid cotton layers that trap moisture.
- Middle layer: May use more than one layer as needed for insulation. Good choices are fleece or wool. As run intensity increases, you may remove some layers.
- Outer layer: Needed when you need protection against wind, snow or rain. It must allow moisture transfer and ventilation.
- Accessories:
- Protect heat loss from head using hats, headband that cover ears and face masks or ski masks
- Mittens are better than gloves for protecting hands from frostbite
- Use shoes that can resist moisture and socks that are made for cold weather use. Deep shoe treads and shoe strap-on grippers can improve safety in snow and icy conditions. Avoid using thick or double socks with tight shoes as this can lead to poor blood circulation.
Other strategies:
- Check the outdoor weather forecast including the wind-chill factor.
- Ensure to warm-up in a warm indoor area prior to starting your run.
- Carry fluids with you or plan for water sources during the run. Replace your sweat losses as needed.
- Avoiding alcohol, caffeine, and be aware of any medications you are on that can cause increased/decreased constriction of blood vessels.
- Ensure adequate calorie intake, carbohydrate-rich foods/snacks are recommended.
- Stop running if you experience any warning signs and seek medical help if symptoms continue.
- If warning signs of hypothermia are noted, move to a warm and dry environment as quickly and gently as possible. Replace any wet clothes with dry clothing or blankets to allow passive external re-warming and seek immediate medical help if symptoms continue. It is advised to seek medical help with frostbites.
- Run with a partner if you are a beginner or have health problems. Be responsible for the other’s safety.
- Consider running on an indoor track or treadmill on extremely cold days.
Nejin Chacko PT, BPT, MSc (sports Med), MSc (OMPT), FCAMPT.
Reference:
- Armstrong, L. E., Epstein, Y., Greenleaf, J. E., Haymes, E. M., Hubbard, R. W., Roberts, W. O., & Thompson, P. D. (1996). American College of Sports Medicine position stand. Heat and cold illnesses during distance running. Med Sci Sports Exerc, 28(12), i-x.
- Fudge, J. (2016), Exercise in the Cold: Preventing and Managing Hypothermia and Frostbite Injury. Sports Health, 8(2): 133–139.