He was referencing this statement from the GP: "Looped around a waist and​ the same person can get up to about 1.0-1.5x with cleats on turf." Point is, if tug-of-war players have been known to lose hands because the rope was wrapped around them, do you really want to see what happens when you wrap it around your waist? Maybe it's safer because your body is much thicker than your wrist, but is that really an experiment you want to run?