- Running in extreme cold is hard on the heart and lungs.
- If you have certain conditions, such as asthma and high blood pressure, you should consider indoor workouts as an alternative during extreme cold.
- Make sure to cover exposed skin and wear the right gear when you run in the cold to avoid getting frostbite.
Many runners dread the treadmill, but with record-low temperatures across the country, when should you give in and accept that it’s too cold to run outside?
“There’s not a clear cutoff for how cold is unsafe for outdoor running,” Adam Tenforde, MD, an assistant professor of physical medicine and rehabilitation at Harvard Medical School, told Verywell in an email.
Extreme athletes will push themselves to run in frigid temperatures. The Siberian Marathon earlier this month was held at minus 62 degrees F (minus 52 degrees C). However, the average runner should think twice before lacing up their shoes and heading outside in extreme cold.
“With temperatures below freezing, I am more concerned about the risk for poor footing from ice that can contribute to risk for falling or disrupt normal running mechanics, contributing to running-related injuries,” Tenforde said.
Another risk from extreme cold temperature exposure is frostbite, especially for runners who leave any skin exposed.1 Frostbites can occur within 30 minutes when the wind chill falls below minus 17 F.
Sean Swearingen, MD, director of sports and exercise cardiology at Rush University Medical Center, said he wouldn’t recommend going outside for a run if the wind chill is 10 below zero.
Sometimes people don’t realize how cold the tips of their fingers or toes are getting when their body is warming up from exercise. “They could be putting themselves at significant risk for frostbite” when the outdoor temperature is minus 10 degrees F, Swearingen said.
The right gear can help most runners avoid frostbite. Wear synthetic, sweat-wicking fabric inner layers with a snug fit, wind-resistant and waterproof outerwear, a hat, and gloves.
People with Raynaud’s syndrome, a condition that results in less blood flow to the fingers, are at a higher risk of frostbite and should avoid running in the extreme cold, according to Swearingen.
Breathing cold air can also irritate the lungs, which might lead to a “burning” sensation.
“Colder weather can affect the airways and lead to reduced airflow and increased nasal congestion. This may be particularly an issue for those with underlying lung conditions such as asthma,” Tenforde said.
People with asthma are encouraged to limit cold weather running, but those who decide to exercise outside in the cold should warm up inside first and use a scarf to warm the air they’re breathing.
New runners and anyone with a history of coronary artery disease, high blood pressure, stroke, or heart attack should also consider running inside when it’s severely cold, according to Swearingen. When it’s cold, peripheral blood vessels also constrict to help keep the inner core warm.
“That can cause an increase in blood pressure that’s much higher than what we’re used to when we’re running and that causes our heart to work harder,” Swearingen said.
Experienced runners who want to run in the cold can mitigate risks by warming up inside first, dressing in layers, and managing their expectations.
“It’s more challenging to breathe,” he said. “It’s harder for the heart to do the job it normally would, so the expectations of what their performance might be during cold weather need to be adjusted during the workout.”