With supposedly VERY comfortable shoes, if I wear them all day at work where I'm almost entirely on my feet 8-12 hours a day, my feet are KILLING the next day. I had to go back to the old pair for a few days and try again to confirm, but it was absolutely caused by these shoes. I wore them once two days in a row and I could hardly get out of bed in the morning. I don't know why it happened and it's the only shoe that made my feet so sore.