Gave up for six years, found that running a few miles each day (real struggle at first) helped no end. Did the London marathon twice and numerous shorter running events inbetween, never felt better. Then inexplicably picked up a cigarette and stared smoking again. Unfortunatly with a fucked up knee have been unable to run off the cravings this time although managed six weeks without a smoke last summer, once the semi finals out of the way I really need to make a proper effort and give up for good.