As soon as I tried these on, I literally said, "it feels like I'm walking on tiny clouds". They give plenty of cushion and are super comfortable. I ordered the Medium because I'm a Women's size 8.5-9 and worried the Small would be snug. The Medium definitely isn't snug, but it's not huge either. I've had running socks that were too tight (and you don't want to cut off circulation), so slightly bigger worked for me. I did workout in these too and they kept my feet from getting uncomfortable or sore. Since they're a bit thicker than normal socks, they aren't super cooling but that's not a big deal. The little heel tab is a nice addition too. Overall definitely recommend.