The origin of gymnasion in Greek means "naked-place", "gymnos" means naked and "ion" is a suffix meaning place. Greek exercised nude because they believed that it was much safer so that clothes didn't get caught. Philostratus' treatise (3rd C, CE), the Gymnastikos tells us a lot about focused exercises and athletic training and includes a lot of information from earlier sources. So, gyms are a Greek concept from antiquity that continued into the Roman period. They fell into decline in the Middle Ages, when people trained more for war than sport, but were recreated in the 19th century with the rise of classicism and the appreciation of ancient culture and revised attitudes to health. The Greek gymnasion was a center not only for athletic exercise, however, but was also a place where people read books, drank, talked, practiced dancing, had their bodies scraped down with oil and rubbed, and often where men hooked up with each other. They often included libraries, sex chambers, and eating areas. They did not include the same bathing areas, for which one would go to the Baths. The modern focused qym is a 19th century invention that grew out of health rooms in private men's clubs.