They said that they were testing for the result of "resistance training" in rats. For rats that means climbing a wall with weights tied to their tails.
However, if a human was going to do resistance training, they would probably do it by lifting weights. There are other ways, I suppose, but that's the main one.
Weightlifting, once you get to higher weights, is a pretty cerebral activity that requires perfect form and close attention to training schedule, repetitions, amount of weight, and diet. It's a very different activity from pulling a weight along because it happens to be attached to your ass and you can't escape it.
