It may surprise you that scientists have actually suggested that no temperature is too cold when it comes to exercising outdoors. It’s true. Almost everyone is safe to work out in cold weather. You should probably choose some heat generating high-intensity workouts instead of a more chill workout like yoga, but your body will do its darndest to maintain a core temp of 98.6 degrees no matter what you choose to do—as long as we follow a few necessary precautions.
In fact, according to Dr. Castellani, lead author of a 2012 paper on Health and performance challenges during sports training and competition in cold weather, it turns out that even though cold can be thought of as dangerous and uncomfortable, more people are injured exercising in the heat than exercising in the cold.
One of the great thing about our human meat sacks is that when we exercise, our bodies generate enough heat to make us feel much warmer than it really is
One of the great things about our human meat sacks is that when we exercise our bodies generate enough heat to make us feel much warmer than it really is outside. Research suggests no matter what the thermometer says, the body will work hard to maintain the healthy and happy temperature of 98.6˚F. That work backfires on us a little since it can lead to a higher level of perceived exertion, but we’ll get into that later.
What Happens When We Get Cold?
When your core (or your torso) is nice and warm, it allows blood to flow to the extremities. But when your core gets too cold, your body stops sending as much blood to the extremities and hoards it for your vital organs and brain. So, what is the best way to keep your hands and feet warm? Heat up your core through physical activity!
It’s not just the core heating up that keeps us safe either. The body has many mechanisms that protect us from the cold. Even that runny nose is helping to keep you safe. When you are cold, the inside of your nose moistens itself to help humidify the cold, dry air that you are inhaling. The runny nose part comes from the excess fluids that end up dripping out of your nostrils.
We’ve all probably heard a story of someone’s cousin’s friend who froze their lungs while exercising outside. Well, please don’t give any credence to that tale or worry about icy cold air hitting your lungs because it is basically impossible for cold air to damage your lungs. Kenneth W. Rundell, the director of respiratory research and the human physiology laboratory at Marywood University says that no matter how cold the air is, by the time it reaches your lungs, it is body temperature.
Interestingly, a thing called exercise-induced asthma is something that some people claim to get from working out in the cold, but that irritation of the respiratory tract is actually caused by dryness, not by the cold. The coincidental thing is that cold air also happens to be quite dry, so those same people would likely have the same problem while exercising in equally dry but hot weather.
Before I get into the Tips part of the Quick and Dirty topic, I want to emphasize that although cold weather exercise is safe for almost everyone, you may want to be careful if you have certain conditions. Conditions such as asthma, heart problems, or Raynaud's disease, may require a check-up with your doctor to review any special precautions due to your condition or your medications.
Dress Appropriately
The rule of thumb is to dress in layers.
The first layer should be a synthetic fabric that will wick moisture away from your skin.
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Polyester - wicking (low water absorption)
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Nylon - wicking (low water absorption)
The second layer should provide some insulation or Loft (which we will talk about later)
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Fleece (non-lined or lined) - almost no water absorption, high Loft value
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Pile - low water absorption, rain resistant, wind resistant
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Wool - low water absorption, rain resistant
The third layer (usually a type of shell) should be windproof and waterproof.
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Gore-tex - the industry standard for being both waterproof and breathable
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Gore XCR - same a Gore-tex but lighter
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eVent - similar to Gore-tex
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SilNylon - a mix of silicon and nylon, wind and rain proof but with low breathability
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DWR - durable water resistant coated fabrics, rainproof, usually windproof as well.
Pro tip: Avoid anything that is made of cotton. Cotton loses its warming power the instant that it gets sweaty or wet. I have actually had cotton shirts get sweaty and then freeze to my skin in the past. That patch of skin has never been the same since.
Extremities Matter
When we exercise and when we get cold, blood flow gets concentrated in your muscles and core, and that leaves your head, your hands, and your feet to fend for themselves. If it is really cold, find a thin pair of gloves (or glove liners) made out of a wicking material and wear those under a heavier pair of gloves (or mitts).
Pro tip: Make sure you put your gloves on before your hands get cold. It is much easier to keep them warm than it is to get them warm.
Your head is where your thinking happens, so you don’t want to damage that! Make sure you wear a toque, wool hat, lined helmet, or (if it’s not too cold) a headband to at least cover your ears. If it is super cold, you may want to invest in a balaclava, neck warmer, or gaiter. My neoprene balaclava gets a lot of use especially in high windchill sports like cycling or skiing.
Pro tip: Buy your winter workout shoes a half size bigger than usual to allow for those awesome thick thermal socks. Don’t bother double layering your socks if they are cotton or nylon, get some appropriate socks if you want to keep your toes intact.
Rain and Wind Are Evil
A serious windchill can be dangerous. It can quickly make the outdoors feel much colder than the thermometer indicates.
Your body will have an extremely hard time maintaining its temperature if it is wet. Water draws heat away from the body 25 times faster than air because of its higher density and heat capacity. We use this to our advantage in the summer months to keep us cool, but it works against us in the winter.
Similarly, a serious windchill can also be dangerous. It can quickly make the outdoors feel much colder than the thermometer indicates. Interestingly, the wind doesn't change the temperature outside, but it does change our skin temperature because the wind steals body heat by blowing away any warm air that surrounds the skin (the Loft). Wind chill is generally measured by meteorologists in watts per square metre, ranging from 1,000 to more than 3,000 but is calculated into degrees for ease of use and understanding for us non-science types.
The term Loft refers to the distance between your body and the outside air. Just like a loft in your house. This space is usually created with layers of clothing. The greater that distance (or Loft), the greater the insulating power, and the toastier you will stay.
But Loft is only effective if the distance it creates remains trapped. If air flows through the loft, warm air is washed away and will fail to keep you warm. In order to trap the air, outer layers should be wind resistant or windproof. Maintaining some breathability is also important because excess moisture must be allowed to escape. There are many newfangled fabrics that achieve wind resistance and breathability.
Be Cold at the Start
It should be no surprise to any of you fit folk that your body warms up once you get moving, so don’t be afraid to feel cold when you first start your chilly outdoor workout. We had a rule of thumb in my running group that you should dress for weather that is ten degrees warmer than the thermometre is telling you.
As you can imagine, performing high-intensity activities can lead to excess sweating, especially if you are overdressed, and that will cause your body and your clothes to get wet. As I said before, water draws heat away from the body 25 times faster than air so there is an increased risk of hypothermia. Or at least discomfort.
Know the Dangers
Speaking of hypothermia, it begins when your core temperature falls to 95 degrees. That is when the shivering starts, followed by a rise in blood pressure. If your temperature drops to 85 degrees, you can lose consciousness and if it goes lower, you could die. One key trick to avoiding hypothermia is to keep moving. “As long as you keep moving you are not going to die because you generate so much heat,” says Dr. Tim Noakes in his paper on exercise and the cold.
The bigger risk for most of us is frostbite because it is quite sneaky. The first sign of frostbite is numbness, then a tingling or burning sensation. The risk of frostbite is less than five percent when the air temperature is above 5 F (-15 C), but the risk increases when the windchill kicks in. With a windchill below -18 F (-28 C), frostbite can occur on exposed skin in 30 minutes or less. So keep that skin covered!
Eat Warming Foods
What you eat and how hydrated you are can affect your warmth slightly as well. We all know that our bodies create heat by burning calories but did you know that if you don't have adequate calories available to burn it can be harder to stay warm?
Please notice that I said adequate calories. There is no evidence that overfeeding yourself will help you keep warm but fuelling appropriately is a little more important when below freezing temperatures are involved.
Some spicy foods naturally raise the metabolism and speed up the heat making process (ginger and capsaicin are good for this). Food that is already warmer than your body temperature (like soup or a hot cocoa) won't actively take heat away from your body, so it will, in essence, keep you warmer.
Being adequately hydrated is also helpful when trying to stay warm. Water is quite good at retaining heat, so it is thought that by keeping your body well hydrated there will be more moisture in your body to retain the warmth.
Can You Acclimatize?
There is a myth is that you have to acclimatize to cold, similar to the way you do with heat. It is absolutely true that you can adapt to hot weather and I put this to the test while training for an Ironman Triathlon in Thailand. Acclimating yourself to hotter temperatures than you are accustomed to can improve performance, make you sweat more efficiently, help you sweat out less salt, and actually increase your body’s blood volume.
Your body uses a significant amount of energy to keep you warm and to humidify the air you breathe and this can be reflected in your heart rate or your perceived exertion.
Sadly, exercise physiologists don’t see similar adaptations to cold weather. The body’s main responses to cold which is simply constricting the blood vessels that are near the skin, shunting blood to the body’s core and shivering do not seem to improve by spending more time in the cold. That is true whether you are a sedentary couch surfer or a hard-charging Winter Olympian.
“Right now, we’re not sure if there is any degree of habituation,” says Robert Kenefick, of the Army Research Institute of Environmental Medicine. "We have all kinds of adaptations to heat—we sweat more, our sodium levels go down, our heart rate goes down. But we don't appear to adapt as well to cold." So, it appears that the reason some of us are OK with cold showers and running in negative 20-degree weather is simply a matter of mindset, not some superhuman genetic mutation.
Increased Exertion
Finally, your body does use a significant amount of energy to keep you warm and to humidify the air you breathe when you exercise in the cold and this can be reflected in your heart rate or your perceived exertion. Not to mention that cold weather is often accompanied by snow on the ground which means unstable footing.
The amount of effort a runner, for example, may need to exert to run the same route in the winter vs. the summer can be as much as 10-20% higher simply due to the stabilization that needs to occur with every step. You can compare this to the difference between trail running and road running, you will likely see a 20% increase in your heart rate when running at the same speed on a trail as you would when you are running on the road. Couple this with the other “keeping warm” factors and you will likely get pooped-out faster in the cold.
So, there you have it. As someone who grew up in the most northern city in Canada with a population of over 500,000, a drippy nose, watering eyes, frosty eyelashes, and puffs of condensation wafting out of your mouth are all points of pride in my world. I hope I did a decent job here today of bringing you over to my side of the argument of making outdoor workouts, despite the frigid weather, more appealing. Or at least less intimidating.
Look at it this way, every four years we gather athletes from all over the world to celebrate the fact that cold weather exercise can be both fun and impressive. If the Winter Olympians can do that, surely we can get out on our fat bike and enjoy some snowy trails.
For more cold weather info, snowy tips, and to join the chilly conversation, head over to Facebook.com/GetFitGuy or twitter.com/getfitguy. Also don't forget to subscribe to the Get-Fit Guy podcast on Apple Podcasts, Stitcher, SoundCloud, Spotify, Google Play or via RSS.
Image of couple working out in the cold © Shutterstock
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