Rei - The Japanese act of bowing

The Rei occurs as we are standing up completely straight, and the next in breath begins, when there is no where up to go... naturally we bow, relaxing out from our center... just before we reach the pinnicle of the bow, our air flows out... as we breath in again, we rise back to our upright position; but in fact, since we bowed as a result of upright standing, we were upright the entire time.