After two years and less than a pack a day (you give a couple out occasionally?) any permanent damage will be negligable, what will be tough is the recovery phase. Exercise your wind, ride a bike or go for a run, especially up some stairs. There are professional hockey players that still smoke, they just have to work harder to be able to play. Two weeks of hard training and you'll be right as rain, providing you don't discourage yourself due to discomfort or have a heart-attack (which would be rather discouraging). Push your limits but listen very attentively to your body. I always liked the "get tough or die" philosophy when it comes to getting back into it but it's a matter of taste (and foolhardiness!)