When the WeatherCan air quality alert flashes the number seven, a heavy feeling in my stomach takes hold. It clearly doesn’t understand me or my circumstances when it tells me to consider rescheduling strenuous activities outdoors. It doesn’t know that for some of us, being outdoors is integral to our well-being. It doesn’t know that moving outdoors may be our only option to get to work or that I’ve been training for months for a race, and I really need to get this session in. So, what should I do?

Typically, in Canada, we’re lucky enough to have good air quality. In fact, most Canadians live in areas where air pollutants are lower than air quality standards. In other parts of the world, where air quality is poorer, these standards are often exceeded.

We know that air pollution is bad for our health because when we inhale the mixture of gases and particles, it can affect our lungs, our heart, our brain, and many other systems in our body. In fact, air pollution is one of the leading causes of death. But given that most of us don’t have the luxury of moving our home just because of air quality, thinking about what we can do to manage our risk is important.

Exercise is an important tool in any health management strategy and by exercising, we are reducing our baseline risk of disease, which in turn could reduce pollution-related health impacts.

So, what happens to our bodies when we exercise outdoors when there is an air quality advisory? 

During exercise, breathing more heavily increases our dose of air pollution and impairs our nasal defences. The increased demand on the body could make exercisers more susceptible to the effects of air pollution.

Watch this video to learn why exercisers might be susceptible to the effects of air pollution: Why might exercisers be susceptible to the effects of air pollution?

Despite the potential risks for exercising in air pollution, the beneficial effects of exercising generally outweigh the negative effects of air pollution. That means, even if you live somewhere polluted, which most Canadians don’t, exercising is good for you.

Even in areas that have high background concentrations of air pollution, cycling moderately for 75 minutes or walking for several hours a day would still reduce your risk of death.

In Canada, the personal dilemmas we face more often surround times when wildfire smoke blankets where we live and we feel trapped indoors. In those instances, what should we do?

A good place to start is the Air Quality Health Index (AQHI) or setting up the WeatherCan app to send you those anxiety-inducing alerts about what to do when the air quality is poor. Exercising indoors is always a good first option. Can you move your run to the treadmill in a gym or at home? If this is an option for you, just make sure the gym has their windows closed and they have something to clean the air such as a HEPA filter. If the windows are open, or there isn’t a HEPA filter, then it would be the same as going for that run outside.

For some of us, being outside is integral to our well-being. For others, the thought of 10 kilometres on a treadmill seems about as enticing as a popsicle in Edmonton in February. So, if you need to get outside to move, should you go for a walk instead of that run?

Unfortunately, we don’t have a simple answer. Research in healthy people doesn’t suggest that exercising harder in air pollution is any worse for you than exercising moderately or resting. So, if your run means that you are out for a shorter period, even if it’s more intense, you might be better off than going for a longer walk as your overall air pollution exposure could be lower. 

Bear in mind that there isn’t a lot of data on people who exercise for more than about 90 minutes, so we don’t always have comprehensive data to answer these questions fully.

In instances where you decide that it’s more beneficial for you to move outside, let your symptoms guide you and if you have any symptoms related to air pollution, such as chest tightness, wheezing or shortness of breath, these are not to be ignored.

Like the person who meditates for five minutes in the morning, but is distracted and stressed throughout the day, there are many other hours in the day that we can do something about our exposure to air pollution. Having a portable HEPA filter at home is a great way to reduce your exposure to harmful particles from wildfire smoke.

You can also consider wearing an N95 mask during exercise. If you are someone with any kind of lung disease, including asthma, chat to your doctor first. Although it may decrease your overall exercise capabilities, it is one way to reduce your exposure to particles from wildfire smoke.

If you are keen to learn about other ways you can mitigate your exposure to air pollution during exercise, such as when to exercise, and potential ways your diet may help check out this video: How can you mitigate exposure to air pollution during exercise?

So back to that WeatherCan alert on my phone; would I go for that run? Like all good decisions, it depends. The smell of smoke makes me nauseous, so if it smells too smoky out, I’ll probably skip the run. But what should you do? My advice: weigh the AQHI messages with any mitigation strategies you can employ, along with the circumstances of your life and well-being.

You may also like: Nasal Breathing for Performance


Alison Jackson Canadian cyclist on the cover on IMPACT Magazine

Read This Story in Our 2023 Summer Outdoor & Travel Issue
Featuring Alison Jackson, Canadian cyclist and only North American male or female to win the famed Paris Roubaix. Travel the country’s most stunning hot spots by campervan. Become a better trail running by improving your ascents and descents—plus, train outdoors with Canada’s Top Fitness Trainers. Enjoy plant-based summer recipes and so much more.