Ah, but were you to be a professional athlete would you be as happy to take such drugs on a regular basis, knowing that they would probably make some difference to your lung capacity when performing at high levels?
I am convinced that these drugs weaken airways to some extent - I'm not worried about my own, as DO says the effects are probably minimal, but then again I'm not a 200m sprinter. I've observed the effects of racehorses receiving increased amounts of ventipulmin and sputolosin, as well as being scoped with increasing regularity, and I am firmly of the opinion that the more they receive, the more they need, and my observations and experiences over the years also suggest to me that such animals become more susceptible to lung infections.