The other thing that is misunderstood about leverage is how it's used on a football field. Long limbs make it tougher to lift a weight in the weight room, but are a real advantage on the football field. That's why Charles Haley, never a terror in the weight room, was a terror on Sunday afternoons. I realize most great running backs are short, but I think that is more because height offers no particular advantage at that position and there are a 100 guys 5-9 to 6 foot for every 5 who reach 6'3" . At just under 6'2" inches I was the third tallest person in my high school graduation class of nearly 200. Hardly anyone as short as I gets a college football scholarship unless the positions be RB, FB, WR, CB,S, Kicker or punter. Sometimes Nose tackle or linebacker makes it into major college in football, at less than 6'3, but they have to 2 out of 3 on freakisly speed, strength or quickness.