For most people, summertime means an opportunity to get outside and enjoy outdoor activities such as running, hiking and biking. However with an extreme air quality advisory in place, many are still wondering whether or not it’s safe to continue to exercise.
To answer all of your questions related to exercising in poor air quality, we’ve put together this helpful guide to ensure that your health is kept top of mind!
What is air pollution?
Alongside automobile and power plant emissions, wildfires are one of the major contributors to air pollution. Together, these contributors produce three primary air pollutants: particulate matter (inhalable particles at least 10x smaller than the width of the hair on your head), ozone, and carbon monoxide. This is important because, in case you haven’t noticed, it’s smoky outside! Therefore the levels of particulate matter and carbon monoxide are higher than usual. Exposure to these pollutants can have negative consequences for your health:
- Particulate matter exposure can cause inflammation both locally at the lungs and throughout the body. There can also be deposition of particulate matter directly in your lungs or translocated into the bloodstream to your organs. Thus, exposure is associated with respiratory and cardiovascular conditions including myocardial infarction, stroke, atherosclerosis, bronchitis, and asthma.
- Ozone acts as an irritant to your airways. This can impair lung function and lung defense mechanisms, and lead to airway hyper-responsiveness associated with lung inflammation.
- Carbon monoxide can interfere with proper oxygen-binding to your red blood cells, leading to attenuated energy production in your cells, and increase levels of oxidative stress by creating a “pro-oxidative” environment.
Do the benefits of exercising in air pollution outweigh the risks?
Exercise may increase the susceptibility to air pollution, and therefore exacerbate the effects of air pollution on healthy individuals. Exercise primarily alters:
- Breathing – you have to breathe more when you exercise, therefore the volume of polluted air you breathe is higher.
- Pollution dose – exercise also increases the proportion of very small particles that deposit in your airways (instead of being breathed out).
- Nasal defenses – if you exercise at a high enough intensity, you switch from breathing primarily through your nose to through your mouth. Thus, air bypasses your nose where your nose hairs typically act as a filter.
However, regular exercise stimulates physiological processes that counteract those exacerbated by air pollution, such as reducing systemic inflammation and blood pressure. Thus, in most healthy individuals, the beneficial effects of exercise will outweigh the negative effects of air pollution and smoke. With this in mind, use the following tips to guide your exercise habits until this smoke blows away.
If I do want to keep exercising, how should I do it?
If you want to keep exercising in poor air quality conditions, fear not – we have some tips to help!
Top 10 considerations for exercising in poor air quality
- Time of day. Air quality tends to be most compromised around midday, especially during the summer when the temperature is higher. Therefore, if exercising outdoors, consider exercising in the early morning or late evening when pollution is generally lowest.
- Exercise location. Try to avoid exercising too close to the source of the pollution/smoke. If you live close to the source, strongly consider indoor workouts or changing the outdoor location of your exercise. This is one of the most important things to take into consideration!
- Know your medical history. If you have sensitive lungs or a pre-existing respiratory or cardiovascular condition, strongly consider indoor workouts (especially if it is smoky) or changing the outdoor location of your exercise. It may help to consult your physician if you are planning to start a new exercise program.
- Watch for symptoms. If you experience headaches, irritation of the ears, nose, or throat, or worsening asthma symptoms, consult your physician.
- Duration of exercise. If exercising outdoors, considering shortening the length of your exercise bout. You can adjust your intensity accordingly (e.g., incorporate some intervals or make the exercise session harder but shorter), or reduce the intensity as well and plan for harder workouts indoors.
- Exercise condition. If you can, mix in some indoor workouts. This is especially pertinent if your location is close to the source of pollution. This may also be a good time to work on some of the neglected exercises (remember those strength exercises your Kinesiologist highly recommended?)!
- Warm-up! Warm-up your lungs by performing an effective aerobic warm-up. For those with asthma, this can help mitigate the decline in lung function that asthmatics often experience in polluted air.
- Keep an eye on air quality. With forest fire smoke blowing in from other parts of the province, there isn’t necessarily a “source” to avoid. Therefore, check air pollution levels (example here), and make decisions accordingly. For example, these days when air quality is very poor, strongly consider modifying your exercise location to indoors; if you have to exercise outdoors, limit the duration and adjust time of day. But, despite the advisory…
- Don’t stop exercising!!! Smoke and pollution might be “pro-inflammatory”, but exercise is “anti-inflammatory”. Thus, the inflammation in the airways and throughout the body caused by pollution/smoke can be mitigated by exercise.
- *Ultimately, make adjustments to avoid the smoke, but… remember that, in general, exercise seems to be more powerful than air pollution!
Please note that it is very important to continue to listen to your body and different people will showcase different symptoms in response to air pollution. People who are otherwise healthy may have symptoms including irritated eyes, increased mucus production in the nose or throat, coughing, and/or difficulty breathing especially during exercise. If you notice symptoms including chest pain or tightness, sweating, difficulty breathing without exertion, consistent cough or shortness of breath, fluttering in the chest or feeling light headed, contact your healthcare practitioner.
- Giles LV and Koehle MS. The health effects of exercising in air pollution. Sports Med. 2014;44(2):223-49.
- Exercise and air quality: 10 top tips. Breathe. 2015;11(3):239-242.
- General Recommendations for Athletes Training in BC Regions Affected by Smoke, Canadian Sport Institute Pacific