Everything You Need to Know About Running Outside When It’s Freezing

It’s freezing outside and I’m about to go out for a run. 

Rather than waking to the ritualist sound of my morning alarm, I hear creaking and deep thuds in the walls as the house twists and shifts. A frigid morning run is in the plan. After throwing off the covers, I stumble my way to the dresser and check the outdoor temperature. -15C is not a typical day in my neck of the woods, however, this morning proves to be even colder with a -24C proudly displayed by Old Man Winter. Now comes the difficult part: finding the correct combination of clothing so that I don’t freeze and give myself either hypothermia or frostbite!

Being a runner in Canada means choosing one of few options in the winter—either spending inordinate amounts of time on the ‘dreadmill,’ embracing winter and hitting the snow, ice and slush covered roads, or moving to Southwestern BC (my wife’s preference). I am one that that embraces the winter wonderland.

Venturing outdoors in cold temperatures it is inherently important to realize there are two key dangers that loom in dark, frigid mornings—hypothermia and frostbite. Hypothermia is, by definition, when heat loss is greater than metabolic heat production. This leads to a decrease in body temperature. Once the core temperature drops below 36C, a person is technically hypothermic. It is interesting to note that subfreezing ambient temperatures need not be present to induce hypothermia which can develop in temperatures in the teens. Frostbite, on the other hand, is the freezing (i.e. crystallization of fluids) of the skin or tissue under the skin.

To prepare for cold weather outdoor running, it is necessary to take a few factors into consideration:

• Is there a wind? Cold wind can increase heat loss and the cooling effect is proportional to wind speed.  A light head wind (i.e. notable breeze on your face) could push the perceived air temperature from -24C to -36C, easily. This ‘wind chill’ needs to be considered. It can be helpful to plan your running route so that you run ‘into the wind’ for the first part of your run if possible. This will make the later portion of your run more enjoyable when you’re fatigued and drenched in sweat.
• Are you a tall, lean or young runner? Taller individuals typically have larger lungs and as such will expire more warm air while breathing. Lean runners (and similarly young runners) do a relatively poor job of maintaining heat in their bodies comparative to larger athletes. This is as a result of their comparative surface area to body mass.
• Are you a man? Yes, those of the male sex have a disadvantage as freezing appendages is a precaution in very cold weather. Men’s running underwear are important. 

To be best prepared for the cold weather, the following are some practical tips to winter running wear:

• Dress in layers—a thermal base layer that is either wool (will stay warm if damp) or technical fabric (will wick moisture away from skin). Guys should also consider wind briefs as part of their base (this bares repeating from the point above). The next layer on your top is an over-layer. This should also be technical wear that is not too tight to the body. Finally, an outer layer that has windproof abilities. Each layer acts similar to a window pane in that there is insulation from the garment itself, but also a thin air layer between each layer that inhibits heat transfer.
• Protect your extremities—your head, face and hands all count! In extreme temperatures, a double layer of gloves or mittens would be helpful. A toque will decrease heat loss from your head and also protect your ears from frostbite. Cover your face and neck with a tubular bandana (like a Buff). This will keep the air near your face warm decreasing frostbite risk and make breathing easier (as the brisk, cold, dry air is being combined with the warm, moist air held between your face and the Buff).
• Use eyewear—these are not necessarily for eye protection, per se, but will help cover exposed skin on the tops of your cheeks. A very typical location for frostbite to form.
• Be prepared to change—if you are not running straight from your own home, take a change of clothing. You WILL sweat, even in these extreme temperatures. There is nothing worse than getting chilled after a run. Your warm and dry ‘comfy’s’ will be welcomed.

After a few minutes of scrounging around in my drawer and carefully selecting my winter wear, I am ready to face the sound of the frost breaking away from the seal of the front door. The first crunch of the snow pack on frigid ground is welcomed as I am prepared to face Old Man Winter head on.

Dr. Lowell Greib, MSc ND CISSN, is the president of The SportLab. Dr. Greib is the Canadian ambassador to the International Institute of Race Medicine, the global expert body on medical science related to health and safety at endurance events, and the medical director for the GoodLife Fitness Toronto Marathon and The Limberlost Challenge.