Why do football players have that "Puffy" look?

You know, you can look at them and tell they play football. Their neck, face is buff, but in a "puffed up" kind of way.

Other athletes don't have that quality, at least not in the way that football players do.

Power-lifters, weight lifters, body builders, basketball players don't have that feature. The closest athletes with that feature are some hockey players.