First of all I usually wear a 9 in running shoes but the 9 1/2 fit fit better. So I'm thinking they run a little small. I bought these for work where I'm often walking on a wet tile floor and these almost had me flat on my face the first day I wore them, VERY slippery (which was not a problem with my old, cheap Filas). I would expect better from an Asics trail running shoe! I expected better grip!