When smoke rolls in, we move less and feel worse – keeping active may help protect your mental wellbeing.

Take home message

Bottom-line message for the readers, how the research can/should be used

• Wildfire smoke significantly reduces physical activity—including bike commuting, leisure walking, and both moderate and vigorous physical activity —while contributing to increased levels of stress, anxiety, and depression.
• Declines in physical activity were correlated with worsening symptoms of stress, anxiety, and depression; reductions in leisure time and outdoor physical activity appear to mediate the adverse effects of smoke on mental wellbeing.
• People who used tools like the Air Quality Health Index or read public advisories were more than twice as likely to move their vigorous physical activity indoors, demonstrating that these tools can impact behaviour.

Background

• Rising temperatures and drier conditions driven by climate change are creating ideal conditions for wildfires.
• Long-term exposure to ambient (background) air pollution has been linked to reduced physical activity and heightened symptoms of anxiety and depression, highlighting the broader health impacts of poor air quality.
• Until recently, it was unclear how wildfire smoke specifically affected different types of physical activity, or how changes in physical activity might influence mental well-being. Our research helps fill this gap by exploring these relationships.

How the study was done

• 162 participants completed questionnaires reporting on physical activity and mental well-being during two distinct periods: one during a period with wildfire smoke and one during a period without wildfire smoke.
• The questionnaires captured
  • Types of physical activity, including active transportation (e.g., biking), leisure walking, and moderate and vigorous physical activity.
  • Mental wellbeing indicators, such as symptoms of stress, anxiety, and depression.
• We also explored
  • How changes in physical activity were related to shifts in mental well-being during smoky conditions.
  • If physical activity acted as a buffer by mediating the effects of wildfire smoke on mental well-being.
  • If tools—like the Air Quality Health Index or public air quality advisories—influenced decisions to move physical activity indoors.

What the researchers found

• During periods of wildfire smoke, participants reported significantly less leisure-time walking, moderate and vigorous physical activity, outdoor exercise, and bike commuting. At the same time, symptoms of stress, anxiety, and depression increased.
• During periods of wildfire smoke, reductions in outdoor, moderate, vigorous, and total leisure-time physical activity were related to worsening symptoms of mental well-being.
• Outdoor activity and total leisure-time physical activity played a key role in mediating the impact of wildfire smoke on mental well-being, suggesting that staying active may help buffer some of the impacts of smoke exposure on mental well-being.

• Participants who used the  Air Quality Health Index or followed air quality advisories were more than twice as likely to move their vigorous workouts indoors, highlighting the importance of accessible public health tools in supporting healthy behavior during smoke events.

Conclusion

• Wildfire smoke significantly disrupts both physical activity and mental well-being, with reductions in outdoor and leisure-time activity being linked to increased symptoms of stress, anxiety, and depression.
• Supporting people to stay active—either by promoting indoor alternatives in a clean air space or enabling safer outdoor activity during smoke events—is essential for protecting both physical health and mental wellbeing.
• Public health tools like the Air Quality Health Index play a key role in guiding these decisions.
• Bottom-line: When smoke rolls in, we move less and feel worse—keeping active may help protect your mental wellbeing.