I must have a look at STS - been dipping into Cathe workouts with my new OnDemand subscription, trying to find ones that will push me just that bit out of my comfort zone but not totally floor me. I do wonder, though - if it's an advanced weights workout in which Cathe and the class are using 20s and higher, does it do any good to do the workout with my lower weight range? Or should I focus on workouts where the recommended weights are in my range and going just a few pounds higher ? (Bearing in mind that I am quite challenged by my 13lbs in upper body movements and I really CAN'T do bicep curls or shoulder raises with my 17lb at all yet).