If you can see the smoke from wildfires when you look out your window, is it safe to exercise outdoors? Is it any safer to exercise indoors?
Listener Lindsey wrote to me on Facebook and asked:
"With all these wildfires in the Western U.S., how do we know when the air quality is too bad to exercise in? And is indoor air really all that much better?"
That is a great question and very timely, given that a surprisingly large amount of the USA (and Canada) is currently on fire. 2016 and 2017 also saw high rates of wildfires. So what do you need to know before you head out (or not) to exercise in the smoke?
What Is In the Air?
The U.S. Environmental Protection Agency says that smoke from the wildfires is "primarily composed of fine particle pollution from burning trees and other plants." These particles can have a significant impact on local air quality, visibility, and in the end, human health. Forest fire emissions include:
- Particulate matter
- Carbon monoxide
- Atmospheric mercury
- Ozone-forming chemicals
- Volatile organic compounds
The emissions from the forest fires can travel surprisingly large distances and can also produce harmful effects quite far away from the fire location. So, just because you don't live near one of the fires doesn't mean that your air quality won't be affected.
Note: If you have a health condition like asthma, COPD (chronic obstructive pulmonary disease), or heart disease, be extra cautious. Also, pregnant women, young children, and seniors are at increased risk.
Should You Go Outside?
The U.S. Environmental Protection Agency provides hourly calculations of the Air Quality Index, which gives close to a real-time indication of the levels of particulate in the air. This can be a great source of information for determining whether or not you want to resume outdoor activities.
The best rule of thumb is if you’re experiencing any irritation, such as a cough, or stinging eyes, it is likely best to keep your workouts indoors.
The best rule of thumb is if you’re experiencing any irritation, such as a cough, or stinging eyes, it is likely best to keep your workouts indoors (in filtered air buildings) until the smoke clears.
But also keep in mind that everybody responds differently to smoke. Some people aren't bothered by it at all and some are completely unable to handle it. So use your local Air Quality and Health Index (AQHI) to find out how dense it is in your area and then measure your own response. In a way, you can be your own science experiment.
My takeaway is that you can still do outdoor activities, just be aware of how your own body is responding and keep your breathing rate in mind. If your breathing becomes difficult or more uncomfortable than it should be, stop or reduce activity. Keep in mind that when we exercise, we can breathe in 10-20x more air than when we are being sedentary, and this means that you are breathing in a lot more particulate pollution.