I had asthma from age 3 to 5. During that time my parents took me to doctors and used all the treatments they promoted, including giving me shots at home, and a vaporizer that made me miserable. I would fight and scream when they gave me the shots, and then run around the house screaming afterwards. Nothing worked, the asthma kept getting worse and I was having a very hard time breathing. My mom told me recently she would hold me in her arms and was afraid I was going to die. One of the times I was running around I bumped the table, the syrings fell off and broke. I kept screaming so they decided to stop and see what happened.
I figured that if I could compress the tubules in my lungs, as much as possible, i.e. isolate and compress the congestion that I felt, that the tubules would open up when I breathed normally. I tried this, by forcing the air out out out out out of my lungs, out out out, to the point that my face would turn red. My mom would scream at me to stop, so I did it more and would fall on the floor, and the asthma went away. I never had asthma again after age 5.
In high school my favorite class was study hall, because I could time myself holding my breath, and then I went out for track and won my first league championship in 10th grade. I'm convinced that had a lot to do with my breathing.
Anything like pollen or other pollutants in the air does affect me, and can almost stop me from running completely. However I have never used any medications or inhalers for my breathing. Yes the pollution can stop me from running well, or even running at all without feeling exhausted, but I never have an asthma attack.