I am so glad to see this thread as I have been contemplating just the same thing!
I have been an avid exerciser (15 years) and a pack a day smoker for 25 years.
It has only recently begun to interfere with my cardio capacity the past year or two. (I SHOULD get a lung x ray, but havent the nerve)
In any case, Since I started with the
ecig, and using it in the morning instead of an an analogue, I feel an IMMEDIATE benefit to my breathing while doing cardio. I have always been the kind of smoker that wakes up and lights up immediately upon rising. That first one of the day was always the one I was most afraid to give up. I am sure everyone or most everyone has at least ONE cigarette during their day that is the most loved. (I cant believe I just typed that. Sounds sick.)
I still get the nic rush, and altho its not as great with my morning cup of coffee, I figure I can wait til after my workout to light up an analogue if I REALLY need one.