Many reviews stated that it ran true to size so I ordered my typical 9 1/2. However, if your feet are at all wide make sure and order a size up. They felt fine until I started walking in them a lot, then they pinch your toes a little and because of the positioning of the "balance pods" they can make your toes go numb from the pressure points they hit. Unfortunately because I have worn them outside (the issue didn't happen while trying them out inside the house) I can't exchange them for a larger size. I haven't noticed any toning difference, but that is probably because I can't wear them for long periods without having my toes go numb :(