Legs & Glutes is the first workout to come to mind, but you're throwing me off when you say the workout on FitTV was only 30 minutes long. I discovered Cathe off of FitTV, too, and I'm pretty sure I've seen every workout she's got on there (I recorded them all before buying all the DVD's). If it's not Legs & Glutes you're referring to, then perhaps it's Pyramid Lower Body or Lowmax (but Lowmax is more of a step workout).