When is it too cold to exercise outdoors?

Study shows link between cold-weather exercise and onset of respiratory conditions.


“Why am I doing this?” That familiar refrain, uttered under one’s breath in advance of some hearty cold-weather exercise, is most associated with the anticipation of the pain and exhaustion to come.

And while the proven benefits send you on your way, it turns out that initial skepticism might be well founded.

Exercise physiologist Michael Kennedy and his team clearly showed that high-intensity physical activity between the temperatures of -15 C and -20 C significantly influenced respiratory symptoms, including medical conditions such as exercise-induced asthma and bronchoconstriction.

“The good news is all the participants’ symptoms were fairly short-lived post-exercise and were completely gone after 30 minutes of rest,” said Kennedy, an associate professor in the Faculty of Physical Education and Recreation. “However, prolonged exposure to the elements that cause acute respiratory distress can evolve into a chronic condition as an athlete gets older.”

To find out the temperature range in which exercise becomes unsafe for your lungs, Kennedy took his research to the University of Innsbruck in Austria, where his team tested 17 active females between the ages of 18 and 30 who regularly participated in intense exercise. The participants’ lung function was tested after completing running trials on a treadmill in an environmental chamber at temperatures between 0 C and -20 C at 40 per cent humidity.

Results showed more than half of the participants started to experience respiratory distress around the -15 C mark.

“This distress was more significant in participants who were exercising at high rates of exertion,” he said.

To help prevent symptoms like “runners’ cough,” wheezing and dry throat, Kennedy has a few recommendations for elite and recreational athletes alike:

  • Cover your mouth with a buff. The high-quality polyester microfibre of buffs provides high breathability and helps warm the air before you take it in, reducing stress on the lungs.
  • Decrease the intensity of exercise in temperatures colder than -15 C. For example, if you’re training for a marathon taking place in a warmer climate, consider taking it indoors.
  • For cross-country skiing athletes, gauge your intensity levels and delay your return to a warm environment after exertion.

“Although it sounds counterintuitive, going inside immediately after a cold-weather workout causes more stress on the lung because the already-stressed airways have to work harder to humidify the air at a warmer temperature,” said Kennedy. “Take an easy warm-down for five to 10 minutes until your breathing returns to resting levels before you head indoors. You will certainly cough less, and your lungs won’t feel like they are burning as much.”

Next steps for Kennedy involve working with colleagues from the universities of British Columbia and Innsbruck to put forth a case for guidelines on the amount of time, exertion levels and temperature for cold-weather exercise and training.