whilst doing a Cathe (or any other advanced) workout? I tried.....not happening! I still whoop, grunt, groan & if sucking wind can make a sound, I do that too! But, have you truly noticed how those beautiful ladies plaster that smile on their face for the ENTIRE WORKOUT?!?! Is that a make up trick perhaps? I don't get it...I've cried.....but that is a grimace, unpleasant and doesn't really count! Just saying......