You do lots of the same moves in both (sit and stands, squats, static lunges), however, SL&A is done slower and has more rests. Cathe uses a 45# barbell for this one. For LL she uses 35#. They are both excellent videos. LL is tougher in my opinion. But PS SL&A is tough too. I always think I'm home free once the standing work is done, but man do those lying leg lifts get me.