First, I absolutely love the look of these! However, I've always wore the same size in ASICS so when purchasing this footwear I thought it would be safe to order that size but this particular style runs smaller. Also of note is that I have never had to break a pair of ASICS in. I could put them on from day one and start running. This style needs to be broke in and I'm not entirely sure they will be good for running. They seem to be stiff and the sole feels like your stomping. The support is not as good as other ASICS styles. You can also feel every pebble and rock like you were running barefoot. I have only ran a little in these but have bought another style ASICS as a backup.