No. In his "Twelve Books of Architecture", Vitruvius extols the air of Rome (which was thought to shape human development). He said African air creates sophisticated, intelligent people but they are weaker physical specimens. Northern European air creates massive athletic men but they are loutish and unintelligent. Only Rome had the mixture of air that allows for both sophisticated intelligence and physical awesomeness. (I love the fact that Vitruvius' racist stereotypes were 180 degrees opposite modern day racist stereotypes.)

But his stereotypes are understandable. Northern Africa was home to civilization that was as ancient to the romans as the Romans are to us. Northern Europe was tribal and less developed.

Diodorus Siculus writes that in appearance the "Gauls are tall of body, with rippling muscles, and white of skin, and their hair is blond (Book V. 28. 1)."

Livy is a useful source for exhibiting what stereotypical Roman impressions of Gauls were. According to him, Gauls were typically much bigger than Romans but lacked stamina. Their battle strategy would be to use all their strength in one massive charge, but if that failed they would fall apart before Roman discipline and cohesion.

Hopefully others will have more to add, but the Romans appear to have seen the Gauls as bigger (so physically superior in that way) but lacking in stamina and perseverance.

Tacitus in his Germania mentions that the Germans are tall and strong, but more suited to occasional feats of strength than patient labor. They also were less tolerant of heat and thirst than the Romans, but endured cold and hunger better.

Someone correct me if I'm wrong but I've read somewhere that members of Germanic tribes from what is today Belgium or the Netherlands were, at times, chosen to serve as Imperial bodyguards. While this was primarily done because of their loyalty I can't imagine that they would have been put into such a position if they had been considered to be physically inferior.

This is from memory, so corroboration or refutation would be greatly appreciated.