When is the best time to exercise if there is high air pollution?

 ðŸ’¡ Summary:

Exercising is a crucial part of maintaining good health, but the impact of air pollution can diminish its benefits. Several studies showed that exercising outside in polluted air has short-term (temporary) health consequences.

Our advice: Pick 1 or 2 time slots in which you can allocate for exercise consistently. Then, use this "secret" Nafas feature to help you protected!


Exercising at any time is better than not exercising at all.

There are numerous health benefits to exercising regularly, such as improved heart health, increased strength, and increased endurance.

Most people exercise when it is most convenient for their schedule, so they are often at the mercy of the time of day they choose to be active.

If you routinely work out, you've probably heard various pieces of advice about the best times to fit your workouts in. You've probably also heard for a long time that exercising first thing in the morning is the best.

Starting the day with breaking some sweat gives you momentum that will make you more focused for the rest of the day.

However, is it true that morning is always the best time to exercise? What if the air pollution during the morning is high? Will this affect our body?

Let’s dig deeper!

Early morning air quality is the worst

Turns out, the air quality in the atmosphere is very poor from early evening until early morning. This is caused by a temperature inversion, which is a phenomenon caused by the flow of air masses in the atmosphere, resulting in temperature differences in the atmosphere.

This inversion will prevent air from rising upwards, accumulating air pollution near the earth's surface and making air pollution on Earth's surface worsens. The temperature inversion will fade as the air temperature rises during the day.

Inhaling pollutants poses a special risk to athletes

Exercise is essential for good health, both physically and mentally. However, those benefits may be diminished by potential health risks associated with air pollution. The air pollution level, a person’s health status, and the length and intensity of the exercise are all important to consider.

During exercise, a greater proportion of air is inhaled through the mouth, effectively bypassing the normal nasal mechanisms for filtration of large particles and soluble vapors.

Moreover, a higher airflow velocity also transports pollutants deeper into the respiratory tract.

Furthermore, pulmonary diffusion capacity has been shown to increase with exercise, suggesting that pollutant gas diffusion increases with exercise.

9 of the 16 papers reviewed found that exercising outside in polluted air has short-term (temporary) health consequences, with lung function impairments being the most common.

Another study discovered that people who did moderate to high-intensity exercise outside in low or high levels of air pollution had fewer health effects than those who did low-intensity exercise.

The study suggests that for people with pre-existing conditions such as respiratory or cardiovascular disease, even low-intensity activities such as walking may exacerbate the negative effects of air pollution.

The best time to exercise is the one you can do consistently

We realize that you have limited time. With only 24 hours in one day, allocating time to exercise can be difficult to do.

Our advice: Pick 1 or 2 time slots in which you can allocate for exercise consistently.

Then, pay more attention to the outdoor pollution when you’re about to exercise. As much as you can, avoid doing exercise when the pollution is high.

With Nafas, we make this easier for you.

Go to the nearest sensor, and enable alerts at certain hour. Let’s say you’ve committed to exercise before office hours (7 AM), then you can ask Nafas to send an air quality reminder every day at 7 AM.

Once the feature is turned on, you will receive notifications about air quality. You will find it easier to determine an exercise schedule and know the things that must be prepared before starting outdoor activities.

Another Nafas feature that might be useful is getting an exercise duration recommendation based on the level of PM2.5 in your area.

To find out more about this feature, you can read this article.


Can air pollution negate the health benefits of cycling and walking? (2016). Preventive Medicine, 87, 233–236. https://doi.org/10.1016/j.ypmed.2016.02.002

​​Ni, X.-F., Peng, S.-C., & Wang, J.-Z. (2019). Is Morning or Evening Better for Outdoor Exercise? An Evaluation Based on Nationwide PM2.5 Data in China. Aerosol and Air Quality Research, 19(9), 2093–2099. https://doi.org/10.4209/aaqr.2019.07.0362

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