Before ordering these I read the reviews warning that these shoes run small.  Since my shoe size varies from a 7 - 8M or W depending on brand, I ordered an 8W.  I have NEVER bought a size larger than this in my life.  The 8W are small and fit like miniature torture chambers once I do anything but walk in them.  So it wasn't until I used them to work out that I realized just how uncomfortable they were.  Initially they feel very cushioned and supportive, so don't be fooled and like me realize you should return them after it's too late to do so