How are your lungs?

I'm not about to give the big "smoking" lecture, but those who smoke and cycle, do you have days where you can cycle the fuck out of your lungs, and days where you just can't inflate those bad boys to get the bike moving?

For me, the former was last summer when I was going out into Essex with Cycling Club Hackney every Sunday - even felt OK after the Dynamo. The latter is now, sadly. I suspect things will improve once I get used to carrying twelvety-three tons of Almax chain and lock about with me.