Funnily enough, I don't think the majority of the ex-smokers are riding hilly double-centuries. Not at > 16mph, anyway.

Seriously? Lived with a 45 year smoking habit, unfiltered, and it's gone now. I'm a daily runner, cyclist and occasionally do mile training swims. Your lungs will bounce back big time, but you have to train them up. I started doing hard spin workouts at the gym, multiple hour sufferfests. Then running trails, a tough 3 miles became 5, 10, 15. I think doing cycling intervals on the road is a much harder way to go, dangerous, but is will certainly work. MTBing hills can be a killer cardio, but I found it very hard to develop any regualr routine.

Don't listen to any haters, you can rebuild your body & lungs. But, it will mean work; regular/routine/meaningful work.

Thanks for putting things in perspective on the smoking. I am not alone, and of course, all activity improves things. I probably wasn't clear in my initial post, but I was curious as to whether there were specific ways to improve lung function- do sprints help things more than steady riding at set pace for longer periods of time? Specific exercises or Physical Therapies to improve lung function? The electronic tracking makes it easier to see where things are working or not. Analyzing distance, elevation,speed, heart rate,cadence, etc make it apparent hills are my particular bugaboo, and the heart rate suggests I am not getting sufficient air. Just praying for a majick bullet!

Conventional wisdom is simply aerobic exercise is the way to recover from smoking, more is better. Beyond that, I'd expect that normal training regimes are applicable equally to ex-smokers and people who have never smoked.

After a fairly short period - months - we cough out enough tar and have healed enough that the amount of degradation with respect to age is the same as with someone who has never smoked. Recovery begins almost immediately, in a matter of days. But we've already been damaged some during those years of smoking.

The problem is that nobody has taken non-smokers, measured their lung functions, had them then smoke for years damaging themselves, quit and then measure again. The violation of ethics would make that impossible. So it's not precisely known. Although we can find claims that complete recovery is possible, the most credible information that I've come across suggests that at best we can expect around 95% of the lung function that we'd have had, had we never smoked at all.

And I find even that to be pollyanna.

Well, we're never going to know, for the reasons given. Personally I was never short of breath even when I was a smoker, and I've certainly not felt that lung capacity was a constraint on my performance since I got back on the bike. Of course, for all I know I might have been Miguel Indurain in another, non-smoking, life.

In any event, there's more to aerobic fitness than just lung capacity. It's a whole-system thing.

I never was a particularly strong or fast rider. And don't expect or aspire to become one as a sexagenarian.

Huh huh, he said sex.

I took up smoking late in life.... when I was in Army Basic training serving my obligation (at the time). I quit smoking shortly after I retired and noticed had noticed health issues with my breathing. I then developed a foot problem (gout) with a bit of weight gain. I returned to cycling to get exercise... or at least get outside. I've never really enjoyed exercise. But was thrilled to find I still loved cycling as much as when I was eight.

The first couple of years of cycling I was convinced my breathing would never return to normal. Thank God... I was mistaken. I ride everyday I can... just because that is what I want to do... and I still can.

I tried smoking one evening as a teenager. Remember the Bugler tobacco for rolling your own? Smoked one of those followed by a short hot pipe. Then I ran out into the yard and vomited all over the place. Wow, I was sick! Some years later I took up chewing tobacco and that got to be a real habit and very addictive. For at least 5 years after I stopped I would have dreams about having a mouth full of tobacco and savoring it's taste. What prompted me to stop was that I had neighbors on all four sides of me die of tobacco related cancer, plus two cousins. I felt someone was trying to tell me something.