Most people get a health boost from exercise. But for those with heart disease or a lung condition such as asthma, exercising during periods of high urban air pollution can exacerbate rather than improve their condition.
![](https://3c1703fe8d.site.internapcdn.net/newman/csz/news/tmb/2019/howsatellite.jpg)
Source:
https://phys.org/news/2019-06-satellites-health-city-dwellers.html