Smoke pollution: Is it safe to exercise outside?

Smoke Pollution

Amid the devastating bushfires around Australia, smoke pollution has blanketed the city and surrounding areas. The NSW Public Health Unit and the Australian Institute of Sport (AIS) have released a guideline regarding the safety of exercising outdoors in relation to the Air Quality Index (AQI). Each state and territory reports real-time AQI ratings online, which indicates the current level of air quality and advice on how this will affect the health of the individual. The table below was taken from the AIS website and shows the recommendations for exercise in relation to the current AQI rating (see table 1).

The left-hand column shows recommendations for exercise for the general population/low-intensity exercise, while the column on the right shows recommendations for endurance based and high-intensity exercise. The ‘sensitive’ group refers to people over 65 years old, children < 14 years old, pregnant women and those with heart and lung conditions (i.e. asthmatics).

At the time of writing, the AQI for Melbourne is 84, or ‘fair’. The recommendation for the general population at this rating is to plan your strenuous outdoor activities when the air quality improves. For endurance based and high-intensity exercisers with asthma, it is recommended you have a medical review prior to training outdoors.

Why is it harmful to exercise in bushfire smoke?

When we exercise, our breathing and respiration rate and volume increase, thereby increasing the total airway exposure to the pollutants contained in bushfire smoke. Our respiratory tract is designed to trap, transport and remove pollutants when we breathe. When the level of pollutants in the air is elevated, our defense mechanisms become less effective, and as a result start to accumulate in our airways and lungs, causing an inflammatory response. You may experience shortness of breath and coughing. If you are an asthmatic, your symptoms may become exacerbated.

Bushfire smoke can be particularly harmful to athletes (both asthmatics and non-asthmatics) involved in high-performance sport due to the increased intensity and prolonged time spent outdoors. The evidence suggests that the total amount of air passing through the airways is 10 times more during moderate exercise, and 20 times more during vigorous exercise, compared to resting values.

If you are experiencing symptoms such as shortness of breath or any respiratory discomfort that is not normal for you, please consult your medical practitioner.

Useful links:

Real-time Air Quality Rating in Melbourne –

AIS recommendations for exercise in smoke pollution –