That training is to build strength duration for long term hold on target. I know several silhouette shooters who practice with a weighted gun. I use a dowel with a rope and weight on the end of the rope. With the arms extended I roll the rope up by twisting the dowel and then twist the dowel to lower it. Back and forth, up and down over and over. Both ways build strength in the arms but my way also builds strength in the wrists. It is really good for handgun shooting.