Since I started this one, I'll go first: Cardio - Body Max. The bpm during the step and circuits are so high that I would actually rather do Imax or MIC. Upperbody - the biceps segment of PUB. Great googly moogly! Lowerbody - any time Cathe does sit and stands, I cringe. Core - the walking planks of C&W and the inverted pikes of PUB. But let's face it - any Cathe workout is a challenge. There are days when even Step Heat seems too tough to tackle. Man Cathe's energy kills me. I can't imagine doing BC or Imax and having to talk the whole way through!?! What an inspiration she is! Okay - what's your nemesis?