Where do you get the 700 lbs?? I mean, I’ve never heard that one.
They were LARGE PEOPLE and ate lots and lots of meat.
The 700 pound computation comes from the fact that Neanderthals were about 30% heavier than other contemperaneous humans, but all these guys were about 5' tall ~ whether Neanderthal or something else.
Bringing them all up to MODERN sized folks at 7 ft would give you a 700 pound Neanderthal with no problem at all.
The point is to show that they were far more heavily muscled and lived a rugged life, and had larger bones.