1. I’M CURRENTLY RUNNING in Lahore, Pakistan. The air here can sometimes be quite polluted. I’m wondering how running in these conditions affects my muscles. Any ideas?

Madeleine LeBlanc-Reiser, Pakistan

RUNNING IN pollution might not affect your muscles, Madeleine, but it could affect your lungs. That is what 2:28 marathoner and U.S. national 25K champion Chris McNamara told me, based on her experience in running in Beijing, where pollution can pose problems. She says she and some of her teammates became sick after running an Ekiden road relay in Beijing last year. One member of the squad got asthma, another pneumonia, while a couple others came down with bad coughs. While there’s no way to say with certainty that breathing bad air caused these illnesses, McNamara says, “The pollution in Beijing was to the point where you could feel it when you breathed, like you had smoked a cigarette and had stuff in your lungs. It was like what exhaust tastes like, or when you’re in a smoky room. Most of us came back with some respiratory problem, cold, or infection.”

I live and train in Boulder, where conditions are, of course, much better than in Beijing. But even in Boulder we have ozone alerts. According to Katy Human, the science writer at the Daily Camera where I work, ozone forms “when sunlight and warm weather conspire to catalyze chemical reactions between nitrogen oxides and volatile organic compounds. Several national studies have shown that emergency room visits and hospitalizations for respiratory problems go up with ozone levels.”

Some experts say that those with a preexisting lung problem, such as asthma, are more likely to get an attack on a high-pollution day, and that exercising in a polluted environment over a long period of time can increase your chances of getting asthma. Here are some precautions to take while living and running in Lahore, or another high-pollution city:

1. During the worst pollution days, find a treadmill to run on, swim, or, if you have to, take the day off.
2. Since taking a day off is anathema for many runners, on high-pollution days, run early in the morning, before the streets are clogged with cars.
3. Stay away from busy streets when you run.
4. Head out of town if possible. (Of course, you will probably have to drive to do that, thereby adding to the pollution problem.)

Mike Sandrock
is the author of Running With the Legends and is a sub-2:30 marathoner.

THERE SEEMS to be little scientific evidence supporting the idea that air pollution negatively influences short-term running performance. This is a different matter from the probably adverse long-term health effects of polluted air in an exposed population. Certainly, some regions of the world with notoriously contaminated air have nurtured outstanding athletes—for instance, industrial cities in Russia and the former East Germany.

And I well remember the very dense “London fogs” of 1950, in which visibility was down to a few yards, due to high contents of particulate matter (largely from millions of open-grate household fires burning coal). A monster fog settled on London for days. Cars were abandoned on the streets, cinemas closed because the audience could not see the screen, and even the underground stations, often hundreds of feet below ground, were enshrouded in fog.

But runners continued to run, and races were held. I remember a cross-country race during the 1950 fog on Wimbledon Common in which only a few runners very familiar with the course found their way home; the others were rescued gradually by shouting and the blowing of whistles. This dramatic fog killed several thousand Londoners, most of them with already impaired pulmonary function.

After 1950, coal fires were banned, and the great fogs disappeared forever.

Roger Bannister, Chris Chataway, and Gordon Pirie, among other greats of the period, trained and raced hard during this period of high-particulate air pollution, with no apparent ill effects on their running performance. I do remember coughing up black mucus several months after the Great Fog, but the main hazard seemed to be the probability of getting lost on the course!

I believe that air pollution—in most areas and under most circumstances—does not reduce short-term athletic performance. But I concede that extreme pollution with lung irritants will impair all human activities.

Dr. Peter Wood
is this magazine’s Science Advisory Board chairman, a former professor at Stanford, and veteran of 100+ marathons.