| Anyone who continued their active outdoor pursuits during the recent cold snap will attest to the benefits of adding more layers to every part of the body.
An extra layer on the body's core, a tuque instead of a headband and a pair of warm socks made of some space-age material all help keep various parts from becoming painful blocks of ice. Some may have the notion that a scarf or balaclava is needed to prevent lungs from "freezing," too.
The term "frozen lungs," however, is a misnomer. No lung tissue freezes when we exercise outdoors, whether it's a balmy —3 C or a nasty —30 C. (Incidentally, this is the temperature at which Yellowknifers curtail their outdoor pursuits.)
However, that isn’t to say breathing in cold air can't cause discomfort, says Dr. Victor Lun, a physician at the University of Calgary’s Sport Medicine Centre.
"During exercise in cold weather, there are high breathing rates of cold and dry air which lead to respiratory discomfort, often termed ‘frozen lung,’" he explains. "No tissue actually freezes, but there is irritation of the upper airway which causes spasm of the muscles of the airway and increased mucus production.
"This may result in symptoms of burning-type pain, coughing up blood, wheezing, coughing and chest tightness. These symptoms may last for several days."
Yuck. Doesn't sound like much fun.
Curiously, even those who are afflicted with intolerant lungs may not notice any degradation in their performance.
"Since most symptoms come on after exercise, usually there is no effect on performance," says Lun. "However, symptoms may affect recovery, which may affect performance if one has numerous events within a short period of time."
There is some scientific evidence that long-term exposure to cold weather in humans causes long-term lung damage.
"Medical literature (shows) that chronic exposure in humans to cold environments results in changes – 'damage’ to airway passages and blood vessels of the lungs," Lun says. "(This) results in various symptoms of chronic respiratory problems, chronic obstructive pulmonary disease and bronchitis, high-altitude pulmonary hypertension and edema, and right heart enlargement, etc."
There is one catch to this bit of information. Chronic exposure refers to real winter weather, like the kind the folks in Nunavut live with, not the couple of weeks of cold we get in chinook-laden Calgary.
"Intermittent exercise in cold weather would probably not be considered chronic," Lun notes.
And it's not likely any of us is going to sign up for a turn in the harness at the next Iditarod dog-sled race, either. (This is the granddaddy of North American dog-sled racing that goes from Anchorage to Nome, Alaska on the western Bering Sea coast, covering more than 1,800 kilometres in 10 to 17 days.) One study of Siberian huskies before and after this race showed there was some indication of lung-tissue injury. Must have been from the running; can’t imagine they had time for too many smoke breaks.
Lun, who researches exercise and preventative medicine, does offer some tips for those who are loath to exercise outdoors when the mercury dips to a real winter temperature. People with breathing problems, such as asthma or exercise-induced asthma, should take special note.
He suggests people humidify and warm the air they breathe with a scarf or hood. Lun says there are also commercial devices that warm inhaled air. Upon their doctor's advice, those with asthmatic conditions may want to use their medication, such as Ventolin, before exercising in cold weather to prevent any nasty episodes.
Finally, however, Lun says there's only one sure way to avoid the so-called frozen lungs: "Not exercising in cold weather!" |
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