martial arts - of practice bag with suggestible impact receiving characteristic

摘要

A method of filling an athletic bag with water and air. After the bag has been assembled and provided with a push-pull valve which communicates with the interior of the bag, water and air are caused to pass through the valve until the bag reaches a predetermined firmness and pressure; then the valve is closed. The firmness of the bag can be controlled by varying the air pressure therein through the push-pull valve. The water and air are confined in a bladder which, before being filled, is essentially the same size and shape as the cover of the bag.