Re: smoking bad for excercise?
It would seem to me that smoking would negatively effect one's cardio-vascular health (and hence endurance) only if you inhale. Back when I was in the military and the police (basically the same thing in my case) cigarette smoking was common and pipe/cigar smokers like myself hardly rare. Needless to say, field operations and combat are very tiring and require a lot of endurance and the matter smoking never came up so I think that it's likely not the energy sucker we are led to beleive.
Obviously I was a lot younger then and my endurance is not what it was 20+ years back but I have a pretty active life. My spare time goes into construction and hiking although i've never been athletic but I doubt i'd be able to do what I do if spent hours a day inhaling smoke as some of you do.
If you are concerned about endurance smoke less ( I never smoke more then an hour a day) and don't inhale but just taste the smoke like you would with a pipe or cigar.