i'm a 5'11" male @ 185 with 30" waist.
i got small/medium.
i've done every training session in these since i got them. i like them a great deal. they are good at keep my legs warm, especially my knees in the cold.
very good wicking property.
they dry quickly as well.
they do sag a bit when wearing them. i periodically have to pull them up.
i used to use under armor cold gear, gave them to my girlfriend and use these. i like them more. they are 2.5x the price though.
in summary, good warmth and wicking capability - thats what i was looking for.
i recommend them.
also they look badass, like tron without the lights.