With the extremely cold air arriving soon, and all the warnings in media, (and my own history of cold-induced asthma, which I seem to have outgrown), I started to research the effects of running in "cold" air. This topic is difficult to research, as most publications are in/on popular media and websites, and scientific articles are hard to find, and even harder to understand in detail without a very specific medical background. But, being curious about anything new, I tried.

What I found is this:

- breathing cold air can lead to asthma-like reactions in the lungs, increasing the resistance for breathing due to constricted airways and increased mucus. While this mechanism provides a significant reduction of heat loss through breathing in many animals, its effect on heat preservation is minimal in humans.

- several immunological parameters in the lungs change, especially the fraction of certain white blood cells and the levels of certain inflammatory parameters in the fluid present in the airways, lungs, and the lining of the nasal passages. However, no changes of immunological or inflammatory parameters in other body fluids and tissues were found. This means that breathing cold air has an effect on the immunological response in the airways and lungs (lowered protection against pathogens), while the effect (especially delayed effects or stimulation) on the immune system in general in unknown.

- the increased resistance due to asthma-like reactions ("cold-induced asthma") can lead to pulmonary hypertension and edema if exposure is chronic (lasting for days or weeks).

- However, there seems to be no common threshold to these effects - "cold air" is a highly individual term. While in most popular media "cold" is defined as short exposure to something around freezing (32F) and anything below, in scientific articles (from which I extracted the information), this refers to exposure of 2 hours or longer at "light exercise" (?? walking?) to temperatures of -23C(-10F), and lower.

What does this mean for running?

My personal interpretation (as a total layman in medical background) of the findings of my (very limited) research is this:

Run in "cold air" only if you feel good doing it. If you experience serious breathing troubles (which do not go away after a few minutes), or coughing during or after your run, the temperature is "too cold" for you body, and it may be better to either just walk, or stay inside.

This threshold may be at 30F, 0F, -10F, or much lower, it is a highly individual thing. You are your best guide.

Happy running, trailers!

When you're out in "cold" air ("cold" being relative to the person - from +30F to -40F or so), sometimes a mask or scarf can help protect your face and help moisturize the air for intake. More sophisticated gear can be more proactive. ColdAvenger is one of the products that can help, but there's others. I've only used face masks, but a Finnish runner/ xc skier in another group says he has used one of those proactive masks (don't remember which brand) and said they can really help if you're out there day after day in cold temperatures.

I've only done a 5k at near -30F but many of the winter ultra runners are out overnight, sometimes several days, in whatever nature dishes out - whether it's rain or -40F or wind. Sometimes they just take shelter, if they can.

I agree it's hard to find information on performance in cold temperatures. I looked several years ago, and most running stuff considered 40F cold, skiing competitions have a low temperature cutoff at about -6F, iirc, so most information seemed to be from military studies, which was a bit different than running.

There have been studies showing that even down to -40 degrees the exhaled air is still coming out at body temperature, so our bodies have do a tremendous job of keeping the lungs warm.  One of the primary problems with cold air is it contains much less moisture, and this can be a big problem since you can dry your throat and upper respiratory system.  To combat this, any breathing barrier will help moisturize the air by mixing slightly with the warmer exhaled air.

For asthmatics, a preventative puff from their inhaler before exercising in cold has been shown to improve lung function.

Acclimatization can occur, so the more you are exposed to cold air the better you body will regulate lung function.

Here are some tips for reducing the symptoms of exercise-induced asthma:

• Be sure to warm up before working out. "A proper warm-up for at least 10 minutes with a gradual increase in intensity can help prevent symptoms," says Miller.
• Take precautions when it's chilly outside. "If it's cold, cover your mouth and nose to warm the air," says Miller. Or "move to indoor areas that are well-ventilated and have humidified, warm air."
• Use an inhaler. Inhalers contain albuterol, a beta-agonist bronchodilator. This class of drugs is effective in 80% to 90% of people with exercise-induced asthma. As a preventive therapy, it should be taken about 15 minutes before exercise. The effects can last for up to four to six hours. Your inhaler can also be used to relieve asthma symptoms after they flare.

Great comments, AT and SillyC.

I think inhalers can be very beneficial for exercise-induced and cold-induced asthma. Asthma has no "function", or benefit for the body, in the sense that it would protect the lungs, or decrease heat loss. Without the inhaler, many people would not be able to exercise at the level they want or need to, just because of the restriction of air flow, so it makes sense to use the albuterol.

I read an article a while ago, in which the importance of correct dosage was stressed, especially during exercise, where people tended to use the inhaler more often than recommended or necessary (as far as I remember, it was every 4 hours instead of every 6 hours), but I don't remember what the main effect of "overdosing" was that lead to concern. On the other hand, who exercises more than 6 hours on a regular basis?

Great comments, AT and SillyC.

 

I think inhalers can be very beneficial for exercise-induced and cold-induced asthma. Asthma has no "function", or benefit for the body, in the sense that it would protect the lungs, or decrease heat loss. Without the inhaler, many people would not be able to exercise at the level they want or need to, just because of the restriction of air flow, so it makes sense to use the albuterol.

 

I read an article a while ago, in which the importance of correct dosage was stressed, especially during exercise, where people tended to use the inhaler more often than recommended or necessary (as far as I remember, it was every 4 hours instead of every 6 hours), but I don't remember what the main effect of "overdosing" was that lead to concern. On the other hand, who exercises more than 6 hours on a regular basis?

Agree for normal folks.

"Overuse" of asthma drugs has led to cyclists being banned or losing grand tour results, even if the authorities find that there was no intention to cheat and the intake was inadvertent (see Alessandro Petacchi) ....

FTYC, that sounds about right.

 

Another way of looking at this is that Exercised Induced Asthma is a repetitive stress injury from exercising in cold (but really, it's very dry) air - that's how I view it. The percentage of winter olympic athletes that use albuterol (which is not banned or even TUE) is insane - something like almost half?

 

But is "don't exercise in cold air because it's too cold for you" really a better solution than "use an albuterol inhaler"?  As below....

 

The albuterol is really well tolerated.  There can be some side effects, but the dangerous ones are apparently very rare, and the common one (shakiness) not typical anyway at the dose that is used for EIA, and if it does happen, it's only a bit annoying, and soon forgotten once you start running.

 

If I were to stay inside and not run when it was too cold for my lungs, I'd be inside 6 months out of the year.  So I use the inhaler and it works like magic.

 

I don't know why you were looking into this, but it doesn't pay to "avoid" the inhaler when you need it.  Once the inflammation starts, it can be hard to stop it.  I've noticed that when I stay ahead of my EIA, I use much less medication overall.

Totally agree. I try not to become dependent on it (and don't need it in the winter), but in the summer I have tried to "avoid" it before, and always end up regretting it 20 minutes into a run when I can't breathe.

FWIW, I used my rescue inhaler 2x during my last 50 miler, and that took me 12 hours.  It helped my breathing tremendously, even though the heat and cold were not an issue.