The World Health Organization (WHO) reminds us that physical activity has significant health benefits, improves overall well-being, and contributes to preventing and managing non-communicable diseases. However, globally, 1 in 4 adults do not meet the global recommended levels of physical activity.

Exacerbating that statistic are summer weather-related events. Wildfire season hits British Columbia every year, blanketing much of the province in forest fire smoke, and recently, heat domes became a new reality in this province.

As a result, weeks of poor air quality are common across BC, posing questions about the best way to maintain physical activity safely, whether it’s indoors or outside.

Image via Province of BC

Smoke from forest fires can irritate the respiratory system and cause systemic inflammation. According to the Government of BC, forest fires are the second largest source of fine particulate matter from wood smoke in the province’s forest, and fire emissions can travel large distances and produce harmful effects far away from the fire itself.

So what is the best way to remain physically active during prolonged periods of poor air quality? What can British Columbians do to minimize their risk while exercising safely? And, is wildfire season the only time to worry about poor air quality in BC?

As climate change continues to cause more extreme temperatures and weather events, it’s imperative to understand how the environment impacts access to exercise.

Speaking to Michael Koehle, sports physician and a physiologist who researches the interaction between exercise and the environment and is the Director of Sports & Exercise Medicine at UBC, BCRPA discusses air pollution specific to British Columbia during wildfire season, and how to mitigate exposure to harmful pollutants during physical activity.

This interview has been edited for length and clarity.

BCRPA: Can you explain what you’ve found in your research on the interaction between exercise and the environment in BC in terms of air quality?

MK: We have two events in BC that contribute to poor air quality for people to be aware of. We have wildfires and we have heat domes. During a heat dome, there are very high levels of ozone, the gas that’s created when the sun converts pollutants into ground-level ozone, which is a bit of an irritant. And I think we can expect more heat domes.

Air pollution causes or worsens many diseases across many symptoms and shortens our life expectancy – it’s bad for us. But exercise is good for us, and we use it to prevent and treat disease.

As air quality gets worse, as it has in BC over the last few years with so many wildfires and the heat domes, people have a lot of questions about, well, is it safe to exercise? Or how do I make exercise safe?

That’s the kind of question that we’ve been researching to help give people meaningful guidance because the answer isn’t to be sedentary.

BCRPA: How can British Columbians determine when the right time to exercise during wildfire season is and how to find the right balance between getting physical activity and avoiding the ill effects of air pollution?

MK: The number one thing to do is monitor air quality. The Government of Canada website is quite good for that, and I like an app called Plume Labs because it has nice forecasts for air quality.

Even during wildfire season when we have a few weeks of bad air quality, there are times when the air quality is better and worse within the day and at different locations. For example, in the Lower Mainland, there can be a big difference in air quality between Richmond and Deep Cove in North Vancouver because being close to the water and the wind direction makes a difference.

BCRPA: What should British Columbians be looking for when they’re monitoring air quality for physical activity?

MK: Canada has its own metric called the Air Quality Health Index (AQHI) which goes from zero to 10. But during wildfire season, it can go well above 10.

When you’re at the low end of the index, you probably don’t need to think about when a good time for physical activity is.

At the higher end, around four or above, you should choose the best time of day to exercise, choose the best location or go somewhere you can access good air quality indoors. Some people will have access to a facility with air filtration or air conditioning which can really make a difference.

“Before I started doing this research, I would have thought to avoid high-intensity exercise, but it’s the duration that’s the issue.”

BCRPA: So, for indoor facilities, like community recreation centres, it’s important to have proper air filtration to provide people with a safe place to exercise if they can’t plan or access physical activity safely.

MK: That would be really good. Most community centres will have some sort of filtration system and so that’s generally better.

It’s more of a concern if people are trying to exercise at home because, in British Columbia, we don’t have a lot of air conditioning in people’s homes. It’s important for people to not assume the air quality indoors is better, especially during wildfire season because if you don’t have air filtration in place, that poor air quality will get indoors. Having access to a community centre with air filtration and an exercise area is beneficial.

BCRPA: What is an important consideration for physical activity during poor air quality that is often overlooked?

MK: People tend to only focus on air quality during exercise, but for the rest of the day, that air pollution is still bad for you.

When you are thinking about physical activity, we want people to avoid low, long-intensity exercise. During the long bike rides and long hikes, you’re going to have a very large dose of air pollution.

A shorter, high-intensity workout, like a 20-minute run, is going to be much better than a five-hour hike or four-hour bike ride.

Before I started doing this research, I would have thought to avoid high-intensity exercise, but it’s the duration that’s the issue.

We’ve studied this in many ways, and we really didn’t see much of an intensity effect. If you must choose duration or intensity, I would orient people to shorter, moderately vigorous exercise and not the long, low intensity.

I hate to say, don’t go hiking, but that’s the stuff that we worry about the most during wildfire season.

BCRPA: What about the rest of the year? What should British Columbians know about the relationship between air quality and physical activity?

MK: It’s sort of a different solution in that for the rest of the year, it’s more about getting away from the general sources of air pollution, like construction sites or heavy industrial traffic, and exercising away from major arteries.

People would be surprised that even getting a few metres away from cars and buses makes a difference. Once you get a few hundred metres away from a pollution source, like a busy street, the pollution drops down to background levels.

Protective strategies for exercising during poor air quality. Infographic via British Journal of Sports Medicine (BJSM).

During wildfire season, air pollution is a blanket over the entire province, basically over western Canada so the problem is, you can’t get away from that.

I think we’re lucky in that for the rest of the year, we don’t have to think about it so much, and that’s not the case in other parts of the world.

Key Takeaways:

Wildfires and extreme heat contribute to air pollution in BC so it’s important to plan out your daily physical activity to minimize health risks.

♦ To monitor air quality,
♦ To plan exercise during windows of better air quality or in locations with better air quality,
♦ To seek facilities with air filtration if possible, and
♦ To avoid long-duration outdoor exercise.

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