I read all the reviews about ordering a half size larger in these shoes. I ordered an 8 1/2 which is what I wear in Reebock and Brooks. The 8 1/2 fit me fine. I plan on training and wearing these in a zombie run (runforyourlives.com) and Tough Mudder. I saw a video review on youtube for these shoes and they had outlasted a year and about 5 mud runs - so that sounds good to me. After the first day I worked out in them (running, box jump, lunges, etc.) my calves were super sore. The shoes definitely make you use your leg muscles differently.