Nothing to do with the classics. It upgrades the workout. I use them for running (8 - 16 km). They breathe very well. The foot doesn't sweat and they stay in place without tightening. With size 43 shoes, I got size 43-46. We'll see if they stretch out after a few washes. So far, they are worth it and then some.

UPDATE
After 2 years, they have become ... bone.

Just what you need for sports activities. Proper fit and support! Combined with a good pair of athletic shoes, you feel more stable in your stride or step and have better performance. As silly as it may sound, it's true.