Can I still exercise when it is smoky outside?

The valleys in Southern Oregon are filled with the thick smoke of wildfires again and suddenly the outdoor activities are shifted indoors.  For many people who don’t have respiratory conditions, they’re tempted to go outside for some exercise.  If this is you, there was a study done in 2016 that looked at the benefits of physical activity, mainly walking and biking, versus the risks of inhaling the smoke.  In general, some exercise is better than no exercise.  It was only in the upper extreme smoke concentrations (>50mcg/cm of PM 2.5) that the risks were greater than the benefits when you spend over 5 hours biking or 10 hours walking. (The PM 2.5 levels are the part of the air quality index (AQI) that can be most concerning because the PM 2.5 particulate is what can cause the most cellular damage.)  Of course the harder you breathe, the shorter that time should be, but brief periods of exercise can definitely be beneficial up until you get to 50 mcg/cm.  For those who must work outside, the N95 face mask is the best to keep out the small particulate in the air: no bandanas and no hospital masks that only use the metal clip at the nose for a seal point.  If at any point your throat is sore, get a headache, begin coughing, or in any other way feel your breathing is restricting, seek clean indoor air.