Hi, i have moderate asthma that is triggered by a variety of things including bad air (ozone, dust etc). What I do is still run by take my fast acting inhaler & puff before I start & have with me while I run. I also chew gum & take plenty of fluids as I find I am less prone to attacks if my throat is not dried out. Unfortunately for those running with me I'm a mouth breather so sometime my breathing will be quite loud. I also find that if I'm starting to get congested I get some relief from Muscinex.