How to keep liquid from forming in salads made with Cool Whip?

How do you prevent excessive liquid from forming when making fruit salads like apple salad and/or orange fluff with Cool Whip? I've had it with making these types of salads just to have them ruined, almost immediately, by the build up of liquid in the bottom quarter of the container. I don't know if this liquid is from the fruit or the Cool Whip, either way it makes for a rather short life to the salad. You really don't even have time to let them set up before the liquid forms and ruins them.