It takes your breath away

Wintry air assails the respiratory system of some runners

— This balmy winter of 2011-2012 has no doubt benefited amateur runners building distance for the state’s biggest marathon March 4. No doubt.

Doubt?

“They’re a little tired-er,” says Hobbit Singleton, who along with her husband, Tom, coordinates and coaches the official training program for the Little Rock Marathon. The training schedule begins in September. So while the 26.2-mile race may be on the eve of spring, its months-long preparation runs a path right through the dead of winter.

“The last two years the weather’s given them more weather-enforced breaks,” she says. “Particularly last year, we had to cancel training totally for one weekend,” and that weekend the trainees were supposed to run 16 miles.

“I can see that some of them are pushing, doing more training, because the weather has been nice,” Singleton says. “We have a schedule that says ‘You have to rest these days,’ and they don’t do it.”

They don’t call her “Momma Hobbit” for nothing.

Saturday the trainees legged their 20-miler - the longest group workout in the entire six-month program - on a day with a mild forecast in the 40s. But they train on Saturdays at 6 a.m., long before the sun gets around to warming Arkansas. Last year, this 20-mile run was postponed until afternoon because snow and ice covered the ground at dawn.

One runner who has enjoyed the uninterrupted winter warmth is Singleton's daughter, Jennifer Miller, 37. Miller has cold-induced bronchoconstriction, a condition that is exactly what it sounds like: a stressful constricting of the airways brought on by cold air.

When it’s really cold out, “it feels like I’m trying to breathe through a straw, like all the air I have access to [has to come] through a straw.”

This is a condition I have, too. In fact, I don’t even run outside when the temperature dips below 40 degrees. After just a short time huffing cold air, I will begin wheezing. A little more and I’m gacking like a cat. Eventually, I’m coughing so heavily I have to stop.

If I quit before the worst of it and re-treat into a heated place, I still wheeze and cough like my grandma - who had emphysema. I don’t have emphysema, but this struggle goes on for two hours.

IT’S A MYTH

Do other runners have this problem? A query posted on the chat board and Facebook page of the Arkansas Road Runners Club of America drew a few responses.

“People that do not run have asked me how I could stand the cold air, and ‘Doesn’t it hurt your lungs to breathe it in?’” says Cindy Knott of Fayetteville. “I think that the cold air doesn’t really bother regular runners’ chest or lungs, because we are out there most every day and gradually get used to it as the weather gets colder.”

Another respondent, Jacob Wells - runner, ultra runner, wildcat perambulator - called cold-weather wheezing “a myth.”

OK, Wells is likely spoiling for a fight, or at least a lively dialectic, but he’s not far off the path. The medical research is surprisingly inconclusive.

COLD AIR, WARM LUNGS

Despite what we may think about how rapidly air comes in and goes out of our lungs, by the time ambient air hits the windpipe, it has been warmed nearly to body temperature by the nose and/or mouth and throat, and saturated with moisture from the same.

That is, of course, under normal respiratory conditions.

What’s normal?

A healthy human at rest takes in 6 liters of air in a minute. That volume doubles with even light activity, such as working at the computer or walking to the bathroom.In distance running, for instance, a human operating at 70 percent or 80 percent of VO2 max (a measure of how much oxygen that person could possibly use in one minute) is exchanging as much as 10 or 20 times the resting rate.

In an advisory for doctors and trainers who work with athletes, “Prevention of Cold Injuries During Exercise,” the American College of Sports Medicine estimates that anywhere from 4 percent to 20 percent of healthy Americans have “exercise-induced bronchoconstriction,” a condition characterized by narrowing of the airways to a threshold greater than 10 percent normal expiratory volume. The symptoms are basically those of asthma.

Similarly, while symptoms may occur in even temperate climates, many more report that cold and/or dry air exacerbate the symptoms, and the College of Sports Medicine has separately labeled such episodes in chilly environments “cold-induced bronchoconstriction.”

“It is not well understood,” says Dr. Paula Anderson, a professor in the Division of Pulmonary and Critical Care Medicine at University of Arkansas for Medical Sciences. “I guess I view it kind of as a continuum, because there are people who have exercise-induced bronchospasms or -constriction ... but then there are people who only have problems when they exercise in cold air and really don’t have problems otherwise.”

Jennifer Miller belongs to the first group. She has had severe symptoms in very dry but otherwise temperate air.

I am like the second group. The separate but parallel arc of causes Miller and I share is reflected in medical science’s two dominant theories for cold-induced breathing problems:

The cooling of our airways causes a blood flow surge such that the bronchioles and alveoli become engorged, and a temporary edema forms that hampers breathing. Or -

It’s not the coldness of the air but its aridity. The hyperventilation of exercise blow dries the inside our lungs, and the “hyperosmotic” tissue cells draw fluid from adjoining cells; the living tissue shifts into a kind of survival mode in some people whereby a number of fluids are secreted inside the lungs to restore moisture.

MOUTH MASK

Miller and her husband are such avid runners that they put more than 5,000 miles on their daughter’s jogging stroller before they retired it. So when she finally consulted a doctor about cold-weather running, he said, “‘I’m not going to tell you not to run. I’m going to tell you to run in the afternoon - and wear your face [mask].’”

Such face coverings range from simple knit scarves or ski masks to fleece and kevlar balaclavas. The Cold-Avenger Pro covering and ventilator ($60) features a protruding polyurethane air exchange that promises to keep wetness away from the lips and skin while effortlessly warming the air you breath.

Another way to reduce symptoms associated with cold-air bronchoconstriction is to breathe through the nose. Even subfreezing air is almost completely saturated and warmed to near body temperature when it has passed the nasal cavity, according to several studies.

Of course, when we’re breathing heaviest, let’s face it, the nose just doesn’t fit the bill.

When breathing exceeds about 30 liters per minute, incompletely conditioned air can reach the pharynx, larynx and lower airways and disrupt what’s called mucociliary functioning, “and you have the release of these mediators like histamine” Anderson says, and “once you trigger these cascades, it takes awhile” to recover.

She recommends a short acting bronchodilator, such as albuterol, that works quickly to open up the bronchial tubes and clear mucus.

But another thing to consider is that all of this physiological response is proportional to existing respiratory impairment - asthma, chronic bronchitis, smoking related tissue damage - and general fitness.

So when Cindy Knott says The cold air doesn’t really bother regular runners’ chest or lungs because we are out there most every day, and Jacob Wells calls cold air breathing issues a myth, they’re correct, in a way.

On the other hand, there’s little evidence that training out in the cold can improve bronchoconstriction for those who have it, Anderson says. In fact, experimental studies suggest routinely experiencing symptoms can damage the mucociliary system and the airway tissue.

ActiveStyle, Pages 23 on 02/13/2012

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