in PS legs
They are squats with a chair. You have the barbell of weights on your back and you sit onto the chair for one count (don't sit back, keep body forward), then you stand up, in the squat position (very close to the chair) and hold for 4 counts, stand upright and go right back to the chair again. These kill after about 5 of them especially after you have already done a number of squats with the PS legs tape. I don't know how many reps Cathe does, but I barely barely finish the last one. Hope this helps.