ECA can be characterized as an sympathominetic. That means that it mimics the sympathetic nervous system. This is the system responsible for your fight and flight mechanisms. While on the ECA stack your body is more zeroed in on the sympathetic mode. Now for sexual stimulation to occur, that is a job of the parasympathetic nervous system. This is the system that is sometimes called the "feed and breed" You need to be in a parasympathetic mode for ideal sexual stimulation. That is why they tell you not to immediately jump on your wife whem she gets home from work. she is still in the sympathetic mode. Now after a nice dinner and glass of wine, the parasympathetic mode is the dominant mode. Which means it is time to screw the hell out of her with your fully pumped erection. ---- the sexual act itself if considered a sympathetic mode because of the increase in peripheral vasoconstiction and increase in heart rate.