I got these shoes for Christmas and I love them - love them love them love them - for Zumba!  I started Zumba in August and just wish I knew about dance sneakers then because my knee got a little sore from months with regular shoes but with these shoes, the tenderness is still there but it's not really painful anymore.  I will say this though; since they're meant to slide on the floor, when you're doing core exercises or moves that don't require sliding, so be careful - you have to work a little more at staying still.  But even then, it's still good because you'll feel your inner and outer thighs toning up!  Anyway, the other reviews recommended upping the size and I totally agree.  Generally, I wear an 8 regular shoe and 8.5 running shoe, so I got these in a 9 and they fit great.