Once upon a time I read about knights of olde practicing with weapons specifically made to be 3 times the weight of their actual weapon. If they had a 7lb sword, a 21 lb practice sword was made. This obviously has benefits in building strength, control and agility. Right now in tkd, hapkido and judo I am learning stick, knife, cane and sword fighting which, according to our art, function under nearly the same principles of motion. I currently have a real sword weighing somewhere in the realm of 9lbs and a bokken of similar (nearly identical) size and structure. But it lacks the weight of the carbon steel and is only 4lbs. This lack is clearly shown in my satisfactory handling of the practice sword, but less than savvy handling of the real sword. Is a heavier practice sword needed for development strength and control? And if so, could someone direct me to a place where I could get a heavier bokken?