[QUOTE=Quinn8it;17158709If you were to watch the progression of an athlete as he reached higher and higher boxes- you could see that his head does not get proportionally higher with each box height increase.. So it does not provide scalable progress.. [/QUOTE]

+1

Yup. Once you get to a certain point, you use the same amount of power to get off the ground. What lets you get on top of higher boxes is how much you pull your legs up.