I did this workout today and I just wanted to share it. It’s an isomentic workout which means a lot of static holds. Challenging and different. I do yoga so holding poses is not exactly new to me but going from a lunge hold to a lunge gives you a good burn. Speaking of lunges those were the worst!!! While I have no problem holding the various warrior poses I find it very hard to drop the back leg and hold it a few inches from the floor for an extended period of time (50 secs as in the case of the video). I have weak muscles around the knee. I call those muscles bike muscles. My husband rode a bike all through childhood and adolescence and he has thighs like a cyclist. I never rode a bike and because of knee injuries and knee problems the muscles surrounding my knee joint are weak (I had a serious knee injury plus a nasty infection in my left knee when I was very young and it still gives me problems). I have to be very careful the way I place my legs when I lunge otherwise my knee cap can slip. The other holds I found a lot more manageable. The plie hold was the easiest one for me. If you try this workout let me know which one was the easiest and which one was the hardest.