I'll start off by saying this is a really challenging but good workout video. I really felt like i got a good calorie burn from it, and she really works your muscles. I think its a harder workout than Jillian Michaels 30 day shred (in a good way.) But the cardio aspect comes from the fact that it's a very lifting weight centered workout. There isn't much by way of moving around.However, my reason for the low rating stems from the fact that it made me thighs and butt huge. I am a petite woman (5'4", 110lbs) and have a pear shaped body. I work out regularly, mostly with workout videos but some elliptical. I am not kidding when I say after about two weeks of doing this workout I couldn't fit into most of my skirts, dresses, and pants in the thigh/ butt area. So the workout is great if you are wanting to become more muscular, and perhaps lose weight. But be forewarned, it can also make you bulk up in the wrong areas instead of gain lean muscle.