No, seriously, what is it? I ask this because I have NO idea whatsoever! One of the black belts in my class mentioned it to me, and I'd like to know more about it. Explain in terms a 9 year old could understand-- my brain's still sort of fried from studying for my exams!
http://en.wikipedia.org/wiki/Core_(anatomy) it's messy and quick, but probably fits what you're looking for in terms of a definition
By core he means your abdominal muscles, back muscles, and obliques (rotation muscles) that power everything else you do wether it be a punch or just standing up. What was it you were doing when the black belt said it was a good core workout? I think this might help you with some good core exercises. http://www.frixo.com/sites/fitness/exercises.html
