I was looking forward to getting these carpet dancers.  When I received them,  unfortunately I didn't notice anything different when I tried to perform my Zumba workouts.  I am probably going to keep the dancer as I'm sure they will work great on hardwood floors.  In the meantime, I've just learned to do lunges and lift my feet off the carpet for the fancier moves that require sliding so I don't injure my knees.  I actually get more of a workout by using this method. I also noticed that with my size 10 shoes that either the gliders are too small or my feet are too big because my feet felt uncomfortable and compressed; my feet were hurting.  UPDATE! I went to a dancer's website (Bloch) and purchased a pair of what they call dancer's sneakers and they literally bend with your feet but with the support of a sneaker in the heel and toes, now I can bend and twist easier.  I think with carpet or floors you always should lift your foot a little to avoid twisting a knee or ankle.