Can running on a treadmill take the place of running outside when the smoke is bad? The levels of smoke in the air fluctuate from day to day. If you are training for a specific event it may be hard to decide whether it is better to turn indoors to a treadmill or keep running outside. There is not a single answer to this question, but following are some suggestions.
AirNow.gov recommends that people should not run outside when the visibility is less than five miles due to smoke. If you have heart or lung conditions this may be different. The AirNow website provides air quality information and maps to help you determine if it is ok to be doing a more exertional type of activity outside.
If you have determined to do some of your workouts on a treadmill, the question then arises about how to get a similar running workout on a treadmill as the one you would get outside. There has been research suggesting you can get a similar workout with some adjustments to the treadmill settings. You should know that your running gait will be different, just like it is different when you run on asphalt vs. trail. The treadmill should be set up 1% on incline to mimic running on level ground outdoors. You may also want to vary your speed throughout your run slightly.
When we run outside we are adjusting our pace frequently due to the changes in terrain. On a treadmill you could just set a pace and stay exactly the same throughout. The overall calories burned tends to be less on a treadmill than outdoors due to increased muscle recruitment outdoors (hamstrings and glutes are used to pull you forward, on a treadmill the belt moves your forward). Also in general people tend to run faster, and longer when running outdoors compared to running on a treadmill. So if you want to attain a specific goal with a treadmill workout you may need to run a little longer to get the amount you need.
Good luck in all the future training endeavors. Here’s to clear skies and more smoke-free days that will let us enjoy the great Missoula fall running weather!