So if you hate running, stop running. There are lots of other ways to meet activity guidelines, just try a few new classes and figure out what you actually enjoy.
Second, give yourself a pep talk whenever you plan on getting active, treating yourself to an inner monologue of all the reasons your workout is, in fact, enjoyable. Even if you don't believe yourself at first, the mind is a powerful tool, and a positive attitude is half the battle.
Finally, remind yourself after your workout that a little sweat doesn't give you carte blanche to eat everything in the buffet line. Comments like, "I worked out today, I totally earned another slice of cheesecake," aren't really true, and they certainly won't help you meet your goals.