It used to be a classic moment in film: After a passionate encounter, the hero and heroine flop back and light up in pleased exhaustion. Why the automatic connection between romance and smoking? Actually, any activity that gets the adrenaline pumping can trigger the desire for a cigarette, even something as seemingly smoke-free as mountain climbing or a marathon.
When your adrenaline is pumping, the chemical norepinephrine is working in your bloodstream. This chemical is related to dopamine and shares the characteristics that give you that rush or stimulate you. Since dopamine is released more rapidly when you smoke, you can trick yourself into enjoying that natural adrenaline high a little longer with a cigarette, explaining why victory cigarettes seem like a good idea [source: Rutgers]. Stimulation might surprise the former smoker, triggering a craving out of the blue. Being aware of the connection can help a quitter decide to have another reward ready ahead of time -- a cocktail with friends, a long hot bath, a favorite meal. Having something to look forward to instead of the smoke will help in curtailing the instant desire for one when that dopamine craving strikes.
To quote Woody Allen: "Remember, if you smoke after sex, you're doing it too fast."