Certainly. It is interesting that the difference in lung performance is pretty marginal. I believe that if you smoke tabs and don't exercise, you will be a wheezing cripple, but if you're fit, you're fit, fags or no.
Indeed, I suspect that the whole, 'smoking is bad for you' thing is a load of old cobblers.
Nevertheless, I currently choose not to indulge.
When I hiked the Inca Trail many years ago my tour group consisted of a bunch of lads from Somerset who had been heavily on the lash the night before the trek began, and a fat bird from Australia. On all five days I was the second from last to reach camp, only saved from complete humiliation by the fat Aussie