Hi Sarah!
Welcome aboard :-)
Let's see if this helps you.
Hardcore Series (HC):
IMAX 3 = Interval Max 3
GSL = Gym Style Legs
KM = Kickmax
MM = Muscle Max
CM = Coremax
LM = Low Max
GS BSB = Gym Style Back, Shoulders & Biceps
GS CT = Gym Style Chest & Triceps
HSC = High Step...