I am attempting to do a week straight (sans Sunday) of classes and today finished day 4. Not sure how younger people do it, but 2 sparring classes in 1 week (with an adult class in between in which we did more dynamic kicks) is doing murder on my hips.  Had to sit out for some of the more intense parts of the class because I still need to be able to walk tomorrow. Hoping to get off work early and be able to attend black belt class but we will see what happens tomorrow.