I can't add much to the way to translate it as explained by chocolate and oldergod, but I can confirm that no, it's generally not said. Personally, I still don't understand it myself, but the psychological significance of work over here is incredible. It becomes much more a part of your average Japanese (males, especially) identity than it does for Westerners. It becomes a core source of self-esteem, much in the same way that friends and family do for us. Telling somebody not to work too hard in Japan is, in a way, like cautioning you not to love your family too much. There perhaps exists in the individual consciousness the concept that there is such a thing as too much work, but it has no immediacy. Much in the same way that you and I know that hijackings and cancer exist, but give little thought to them until they strike close to home.