Much of what Chas and tsl said about having been a smoker applies to me as well, pipe smoker starting at 18, even when I was running a lot and seriously cycling well into the 80's. I had to quit smoking in order to have lumbar fusions in 2004, actually had hung up the pipe and pouch in 2000 when I had a ruptured appendix. No regrets about quitting and less about having smoked, tsl nailed that one, too, you cannot change the fact you did smoke in the past. Unless you have COPD, or a latent cancer, your O2 up take and ability will improve with riding and not smoking, as said by both gentlemen.

I'd do the doctor/checkup thing, if you haven't already done so, and just ride as much as you enjoy/wish. I'm in the same boat as tsl for my speed average, 15 seems to be written in stone for an overall average. I did manage to hold a steady 20 mph average for some long stretches the last 2 weeks, though!!!!!, somehow. I will skip posting my palmares, and resume, to the various World Pro teams I think

Best of luck with your riding, stick around the 50+ forum and enjoy every minute of smoke free riding.

Bill