Women's Boxing in the London Olympics, Wearing Skirts Approved!
I know it sounds strange, but it is very comfortable to wear a workout skirt (like a longer tennis skirt) when doing boxing, kickboxing and muay thai.   Most women who train very hard in the combat sports put very little thought into their training clothes.  It is a little different than being an avid yoga practitioner or fitness junkie.  Assembling an outfit has never really been part of the combat sport culture.  Clothes are practical, comfortable and intended to last through the obvious contact...