Since there are numerous grappling and grabbing maneuvers contained within Goju-ryu katas, it is important for students to strengthen their bodies and maintain overall body flexibility to properly perform the techniques. Therefore, Miyagi Chojun (1888–1953) taught supplementary conditioning with traditional Okinawan weights.
SOURCE: Journal of Asian Martial Arts, Vol. 5 No. 2 (1996): 14 pages.