Good morning Jazz,
I've learned on this forum and other places, that you need muscular strength, muscular endurance and of course cardio to provide health benefits. I'll talk about the strength and endurnce.
CTX workouts are a cross between endurance and strength.
PS promotes mostly muscular strength. They are designed to be used as formatted, but are interchangeable.
Slow and Heavy promotes Premium muscular strength gains.
Gym Styles promotes muscular strength gains as well.
Sometimes your body gets used to the same old same old, and eventually gets use to the exercises you perform, therefore, not gaining muscle or endurance. So, you need to confuse your body to promote these benefits better. Each DVD has different tempo, counting of reps, etc... that will make your body confused and work better.
Use strength, endurance, and a combination of the two during a one week spand to make sure your muscles recover properly. Or use one of many rotations out there, that will best benefit your body.
My point is, get a variety of workouts. The best quality is of course Cathe's.
Janie
"If you can't say anything nice about someone, then don't say anything at all."
-My mother, Mary Cooper-