I just found out that B&J are ALSO appearing on the 3rd season of Biggest Loser Australia, which just started airing. I'm wondering how they've had time for all of this.
While BOTH shows are pre-recorded months earlier, it strikes me as peculiar because Bob and Jillian shot back to back US seasons. And we all know that BL seasons actually take a LONG time to film--around 3 months, right?
Wikipedia says that BL:A S3 shot primarily between October 2007 and December 2007. B&J were not the main trainers, those were Australians in Australia, but because B&J been involved in that show before (they were the main trainers on their first season apparently--you can find YouTube videos if you want to see these episodes), four "rejected" contestants were made into a "Black Team" and shipped to the U.S. to train on the set of the U.S. show by Bob & Jillian. Again, YouTube comes to the rescue because a couple of these S3 episodes are already up there and you can clearly see its the familiar US BL campus and gym we know so well.
Seems to me there had to be some overlap between these guys and Couples. I wonder if they were all there at the same time, using the same gym, but were simply filmed in such a way that the two groups never overlapped on camera. And B&J had to be hopping between groups a bit, although obviously its far less work to train 4 people between two trainers than it is to handle a season with 20 people.