I would love if Cathe could answer this question, because I am having the same problem. I've looked in the mirror to make sure I have the correct angles and it looks good, but when I do the lunges my back leg burns. When Cathe starts the lunges she says that you are mainly working only one leg, which she says is the front leg, but with all the burning on my back leg I think I must be doing this wrong. I know that aquajock said that she feels her front leg when she uses a forward lean, but Cathe doesn't lean forward and says you should be feeling it mainly in the front, so I'm confused. Help Cathe. I love powerhour alot!!