In my personal opinion I honestly do not think that body builders are fit. They may look very fit and look "good" but they do not do fitness.
I have actually trained body builders in cardio training and I have seen it for myself and they cannot even do a quick 20 minute set of cardio without almost passing out.
To my knowledge the supplements that body builders take increase there percentage of water retention in there muscles. This means that they always need to gym to keep their muscles enormous.
If they stop weight training and I have seen it, all the water in their muscles turn to fat and they loose there definition and strength.
If you disagree with me let me know down in the comments and forget to up vote.