I would be very surprised if the DLC had optimal weight training exercises. They could be good exercises in general, and also may help with muscle endurance, but unless they have you lifting heavy, they aren't going to be what you need for weights. (I could be wrong, but I don't plan to download any pay DLC until and if I've fully utilized what's currently on the disk.)

I'd suggest picking up a book called New Rules of Lifting, by Lou Schuler and Alwyn Cosgrove and work through the programs a couple or three days a week. You'll need a set of free weights if you do the program at home instead of in a gym. On alternate days, you can do the Kinect stuff for cardio, endurance, etc.

I'd love for something like this to be on Kinect, since it's fun having a "trainer" and once there is better calibration with the sensor, could optimally check form too.

Of course, doing something that's fun for you and motivating to keep going is what counts in the end.