Let’s face it, winter in Canada is a reality we can not ignore. And for many of us, that means getting outside and out into the cold for work, chores and exercise. But there are ways to improve your comfort and safety while being active outdoors in cold weather.
First, “cold” is what physiologists (people who study human function and structure) call a “stressor,” meaning that your body recognizes cold as something it must hold in order to remain in homeostasis (when your body functions). is stable).
We can immerse ourselves in different types of cold – including cold air and cold water – where the cold environment can be highlighted by wind and snow or rain. Here are some guidelines for training in cold air – there are various tips for swimming in cold water.
If you have underlying heart disease or high blood pressure, talk to your doctor about how long you should stay outdoors and what kind of activities are recommended for you in the winter.
Maintaining core temperature
Interestingly, in a naked or semi-naked state, your body begins to recognize cold as a stress factor at about 28.5 C. At this air temperature, your body’s coping mechanisms begin to ensure that your core temperature is maintained. This is why when you step out of a shower or wear some clothes (like lying on a beach in the summer), you will often shake.
Adding insulating clothing to your body lowers the temperature you begin to feel cold stress. In cold weather environments, our bodies produce a lot of heat when they use energy to move our muscles for activities such as shoveling snow or cross-country skiing. So if we wear proper insulating clothing and do enough muscle work, we can feel quite comfortable – what is called thermal comfort – in cold to very cold weather.
However, there are still ways to reduce the risk and improve comfort while exercising outside in cold weather. Here are some things to keep in mind when making outdoor exercise decisions in the winter.
Cover your skin
Reduce your exposed skin wherever you can. The recently updated guidelines from the American College of Sports Medicine indicate that frostbite, which is a “direct frost damage… of the skin surface”, can occur at only -3 C. Tissues with less blood flow, such as hands, feet and head are more vulnerable, especially when the cold air is extreme (less than -15 C air temperature or -27 C wind cooling).
Freezing can be accelerated by contact with cold materials (metal, snow, ice) and by wet skin. Wear insulating clothing that has a high moisture wicking ability to draw moisture from the skin, and keep your head, feet and hands covered at all times!
Your face should also be covered for a few reasons. Covering your cheeks, forehead, nose and neck improves the regulation of thermal comfort, especially in windy conditions, making activities such as tobogganing or alpine skiing more enjoyable. The skin on your face can take a real hit – even under moderate windy conditions, your face’s skin temperature can drop by 25 C.
If you have any underlying chronic conditions, including high blood pressure or heart disease, you should cover your face. Exposing a bare face to cold – as little as -5 C – involves parts of the nervous system that can increase blood pressure. Simply wearing a toque and a scarf can reduce this increase.
Protect your lungs and respiration
Our lungs are particularly vulnerable to cold air environments, where exercise actually increases the load on the lungs during winter conditions. For good reason, your lungs want to heat and humidify the air we breathe to body temperature and 100 percent humidity. They do a really good job with this at rest, but during exercise it requires a greater effort to condition the air you breathe in.
Add cold air on top of high breathing rate (as seen during exercise) and your lungs will be really challenged to warm and moisturize each breath. Cooling of the airways is associated with a nervous system reaction, and dehydration of the airways is associated with an inflammatory reaction, both of which can contract the lungs (often called cold air bronchoconstriction).
Activity in cold weather at less than 0 C, at moderate exercise intensity (brisk walking pace), also results in respiratory symptoms, including the very common runny nose and feeling of irritation in the nose (itchy, burning sensation). With more intense exercise (such as a hard run or cross-country skiing) the symptoms increase and may include excess mucus, productive cough (get the mucus out) and unproductive cough (irritating cough), chest tightness (difficulty breathing), wheezing and sore throat; these symptoms can last up to 24 hours after a hard workout in cold weather.
You can take several actions to reduce these symptoms. First, a slower training intensity gives your body a chance to condition the air in each breath. Second, covering your mouth with a buff, scarf, or cold weather mask can help trap moisture to moisten your next breath. Third, reduce your total exposure to cold air because even 30 minutes of moderate exercise can increase your symptoms and respiratory constriction. And finally, drink enough water during prolonged periods of cold weather because you can lose up to 100 milliliters of water per hour due to heavy breathing exercise in cold air.
To be prepared
Being unprepared in cold weather increases your overall risk of hypothermia and other cold weather-related injuries. In fact, more than half of the deaths associated with natural weather events are due to cold weather – directly to unintentional hypothermia (severe fall in core temperature leading to death), or when hypothermia exacerbates a pre-existing condition. Note that accidental hypothermia can also occur in moderate cold, potentially putting outdoor enthusiasts at risk.
It is also well documented that alcohol consumption is a significant risk factor for accidental hypothermia along with prolonged exposure and inadequate dressing. Other cold weather injuries include frostbite and frostbite, which can result in serious health consequences if not treated promptly with appropriate medical attention.
I hope this has helped you better understand some of the physiology behind how humans interact with cold air environments. More importantly, I hope you can use some of these tips to increase your enjoyment and safety in the winter, especially when the temperature drops well below 0 C.