"The first impression of a good German Shepherd Dog is that of a strong, agile, well-muscled animal, alert and full of life. It should both be and appear to be well balanced, with harmonious development of the forequarter and hindquarter...The Shepherd should be stamped with a look of quality and nobility, difficult to define but unmistakable when present. The good Shepherd Dog never looks common. It should look substantial and not spindly, giving the impression both at rest and in motion of muscular fitness and nimbleness without any look of clumsiness or soft living."
-quoted from the GSD breed standard.