The gymnasium, if originally for physical training only, soon became in classical Athens a space or building for educating the young, as in the current German use of the term. The palaestra, in origin a school for physical training, is generally subsumed as a part of the gymnasium, and set aside for wrestling and boxing. The form of both, as loosely defined in the structures of the classical Greeks, of a colonnade surrounding an open space, did not need to change, except to get more splendid. The typology was only elaborated in Hellenistic times, when large complexes for education and training were constructed, and given a prominent position within the city. In time, indeed, both were generally subsumed within bath complexes - a combination of Greek and Roman typologies that was largely restricted to Asia Minor. For obvious reasons, it was convenient to have running tracks close to water for bathing. By the Roman period, gymnasia and baths were as magnificent as palaces, ornamented with rare marbles and fountains; in many cases, they became veritable galleries of art (Yeguel 1986, 147-52 for an illustrated typology).

http://rubens.anu.edu.au/raider4/turkey/turkeybook/civic4.html