Porn as only discipline

Why is it that i can't stick to jogging or a diet but watching porn is no problem over the years?
I don't know but I heard that it's because we man have to produce children as much as possible because of the survival off our species and to have an orgasm is a substitute for making children, the feeling is the same so we can relax afterwards and porn makes it all more easy... although fantasy sometimes rules. Is masturbating a life hack?