Sigh !!!!! What the hell did I start here? Ok, brief description, no, I don't run 4 miles a day, I don't run at all. But I do walk 2 or 3 miles, several times a week, when it's no so darn hot as it is now.
I'm in decent shape for my age, not overweight.
DON'T go back to smoking, no matter what the FDA does.
Going back to smoking will be a huge loss for you, in more ways than one.