Well, this isn't really a bug, but Siku said to put it up, so here it is. Basically, you get two weights. You put one on, then click the other. The other doesn't show it's equipped, but the one you put on first does.
When you go to run, you have normal running speed, this offers no type of experience, to my observations, so it's basically, a bug that isn't a bug, as I said in the beginning.