I have done exactly 102 km of running with these shoes on dirt surfaces such as dirt tracks around a field and dirt trails in the mountains. I haven't even stepped on hard rocky paths. I emphasize the dirt terrain because I believe that with shoes that have a trail sole, when running on asphalt, they wear out more easily and quickly on the bottom. So, after 102 km, even though the bottom sole is visually intact, the grips, meaning the treads, are slightly worn out. I made a move to draw a line on the ground on the dirt, and almost half of the sole came off. It was as if it was stuck with mucus. Unacceptable. Before these, I had the Saucony Peregrine 5 shoes, which lasted for 1600 km of running in the mountains, and also some Salomon shoes, which I threw away after 1500 km because I got tired of them never breaking. From now on, I will stay away from Brooks.