How Cold Is Too Cold to Run Outside?

How Cold Is Too Cold to Run Outside?
Photo: Andrey Yurlov, Shutterstock

When I signed up for that spring marathon, I envisioned myself at the end of a breezy race day: exhausted, victorious, and comfortable in weather-appropriate leggings and a tee shirt. What I failed to consider then, and what I am reckoning with now, is the reality of marathon training in freezing temperatures.

Many runners and winter athletes will tell you that running the cold is not as tough as it looks. Sure, the first few minutes suck–but you’ll surprise yourself with your ability to withstand harsh winter days. Personally, I prefer frostbite over any treadmill run that lasts longer than 20 minutes. But is there a point where winter runs cross over from difficult to dangerous? How cold is too cold to run outside?

“Too cold” comes down to personal preference

There’s no clear cutoff when it becomes “too cold” to do a lap around your neighbourhood. The American College of Sports Medicine advises against running outside if the wind chill is below negative 18 degrees Fahrenheit, since that’s when the risk of frostbite increases. This isn’t a hard rule though: Kathy Butler, head coach of Run Boulder Athletic Club and two-time Olympian, told Runner’s World that she’s seen her group train well in temperatures as low as 10 degrees Fahrenheit, although on days when “there was no wind, it was sunny, and they were quite bundled up.”

For most winter days in which temperatures stay above zero, “too cold” will come down to personal preference. “You can definitely exercise in cold weather as long as you take the right preventative measures,” Alexis Colvin, MD, an orthopaedic surgeon specializing in sports medicine from Mount Sinai, told POPSUGAR. Here are some of things to do if you’re a brave soul heading out to run in the freezing cold.

How to avoid cold-related injuries while running

Here are the American College of Sports Medicine’s tips for reducing cold-related injuries while exercising:

  • Cover your head, face, legs, feet, and hands. These areas are at greater risk for frostbite injury.
  • The risk for cold injury is higher when the conditions are wet (e.g., snow or rain).
  • Wear appropriate footwear to prevent slipping.
  • Adjust clothing and layers to help maintain warmth but prevent too much sweating.
  • Be aware of the wind speed. For example, if the air temperature is -1.1 °C and the wind speed is 16 km/h, then the actual temperature will be -6.1 °C. Here’s a calculator to help you figure out the wind chill.
  • Avoid exercise if possible when the air temperature falls below -27 °C. Tissue injury can occur in 30 minutes or less under these conditions.

And here are more tips for making the most of your winter workout:

Wear the right running gear

The key to surviving cold weather runs: layers. “Getting injured or sick while running in the cold is usually the result of not wearing the correct clothing — and sometimes it’s from dehydration, as you don’t expect that when it’s cold,” Butler told Runner’s World.

(Here’s our full guide to running in the winter without freezing your butt off. We also have a video guide offering some examples of appropriate cold-weather running clothes.)

Watch your breath

After running a few miles in 0 degrees Fahrenheit last week, I’m now battling a brutal sore throat. (Apparently the cold air wicked away some of my precious moisture in my mucosal lining. Classic Meredith.) Be extra aware of mouth-breathing while running in cold, dry air. Wearing a mask helps, as does sucking on a cough drop in order to help you practice breathing through your nose.

Look out for ice

When there’s snow on the ground, there could be ice hiding beneath. The lack of traction can result in falls and other injuries. Tread carefully, and opt for an indoor workout if you can’t find a reliably paved path to run.

Don’t be afraid to modify your run

I always tell myself that if something feels off after my first mile, I’m allowed to turn around and walk home. Grant yourself extra leniency in extreme weather conditions. If you really can’t bear missing any miles, consider a hybrid plan of running half of your route outdoors and half on a treadmill.

It also helps to physically modify your route to accommodate layers. Plan a run where you can shed extra layers after the first mile and then pick them up on your way back.

Don’t cool down–warm back up

You’ll want to immediately get out of the cold and either take a hot shower or put on warm, dry clothes. Treat yourself to a hot beverage, too. You’ve earned it.

The bottom line

You can run outside at quite chilly temperatures before you seriously risk frostbite or any other cold-weather consequences. As long as you’re prepared with protective gear, you can listen to your body to acclimate to cold temperatures as best as you personally can.

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