I'm not sure exactly what kind of exercise 'phenomenon' you think this is referring to, but a google search reveals some clues: http://mdn.mainichi.co.jp/waiwai/0303/0308filial.html http://www.udel.edu/History/figal/Hist372/Text/ps3-26.html http://home.t-online.de/home/marinero/Soapland.htm