Gym in Berlin
 

I'm looking for a gym to go to in Berlin when I'll be there is a few weeks. I need one in which I can get day passes or a few days pass, since I'll only be there five days. I'd like a nice one with lots of stuff, but any good one will do. I'm staying near Alexanderplatz the first few nights and then over in the west near Ka De We the other few nights, so anywhere really, I'll be out and about. Thanks for the help.

These people have a gym at the Alexanderplatz and another one in the Europacenter (which is right by the KaDeWe). No info on passes, though, that I could find.