These fit true to size. I wear an 11.  The sides of the shoe don't rise very high which allows more flexibility, and for me is a real plus since my right ankle consists of 2 metal plates and 10 pins making it a bit more square then my left. But the fit was equally comfortable on both feet.  I have a pair of Adidas shoes that I alternate at the gym with, the Adidas make my feet sweat a little, I don't feel that with these shoes.