My only complaint is that the arm resistant ropes didn’t last long at all. They got all stretched and almost snapped towards the bottom. So I just took them off. I still love this thing though. I can notice a difference in all my muscles, lots of firmness all around. Once I started doing it every day I really noticed quickly. I sometimes do squats on it and use my own hand weights and resistant bands while on it. Or I’ll just bend my knees a little and lean forward just a little, engage my ab muscles, and put my arms in a position like a ballerina, or like holding a beach ball and I can feel the firming vibration working my arms too. My knee sometimes bothers me when I run so this is definitely helping strengthen around my knee. I also use the elliptical at the gym to help restrengthen my leg muscles to help my knee.