There is a possible mention in this paper:

Per a paper written by Anne Mussey for the Gay and Lesbian Archives, Ruben Reynaga USNT 421 AERO-VAPORS and Workout Baths possibly circa 2000: “Interview with David Hamilton/Mame and Norm Costas: Workout Baths (531*5W 72* Ave.) was open from 1968-1969. It was not listed in the Portland Directory in 1970, however, it reappeared in 1971 with a new name, Workout Health Studio/Advisco Health Studio (1971-1976). In 1977 it was only listed as the Workout Health Studio and remained open until 1979. In 1980 a new health club was opened in that same location called Olympic Uptown Health Studio and it was listed in the directory till 1983; however, I was unable to find when this health studio closed shop. This block which housed Workout Baths also included a variety of other businesses ranging from a barbershop (Washington Barber Shop) to a luggage store (Fink’s Luggage) and an orthopedic shop. The Playmate Health Club (1974-1976) was listed on 525 SW 126 Ave. Across the street on Alder, the First Presbyterian Church stands (1854). Interestingly enough, the 531 address used to house Camp Here Girls Portland Area Council unt1 1965.

Workout Baths must have been a low-key business, especially to be allowed to continue for such a considerable long time near a church and other small businesses. However, one could argue that most bathhouses ran during late hours after the bars close; therefore, there would be little traffic to bring alarm or annoyance to the other businesses. I did explore the area and found the building where the bathhouse business was located. It looked like a house and it was empty. There is a dry cleaning shop located in the 517 address that once was a barbershop. A bookstore, a beauty shop, and a luggage store presently inhabit this block. I went into the laundry shop and asked the owner (an Asian lady with an extreme accent) if she was aware what business used to exist prior to her dry-cleaning service. She said she had been there for fifteen years, and she did not remember what was there before she moved in. I asked her if she owned the space above her and she replied, no. The entrance that once led to Workout Baths is locked and through the windows, one can see a variety of boxes. I tried calling the listed number (227-8393) but it was disconnected or no longer in service.

My friend took it upon himself to ask some older men at Princeton, a health club on 11th between Alder and Morrison that has a large gay clientele, about the gay community in Portland. Many were aware of the fact that there used to be more gay bars and bathhouses in Portland, yet they had a variety of reasons why gay-oriented businesses such as bars and bathhouses were in decline. The most common reason though was that gay men had other outlets to turn to meet other gay men, besides bars, bookstores, or bathhouses. There were a variety of political and gay-friendly organizations that gay men joined; however, it would be foolish to simply disregard the importance of bars and bathhouses in bringing in the gay community. These institutions serve an important purpose for gay men at every level of life, from those that are totally open to completely closeted. Gay bars often served as the first step towards accepting ones sexuality, at least for me it did. It is evident that sexual minority youth now have access to more gay organizations than sexual minorities from the past, therefore, one can conclude that the importance of gay bars and bathhouses will decrease. By decreased importance, I do not mean that these institutions will disappear. The sex industry will remain as long as the libido of gay men continues. By importance, it is meant that gay men will no longer rely on these institutions solely to communicate with other gay men.

The AIDS epidemic had a tremendous impact on the sexual practices of gay men and eventually, it came to impact the sex practices of the general public. The quick spread of diseases through bathhouses was evident in the past and many gay men would simply attain vaccinations if they discovered they carried or caught a disease. There was an outbreak of gonorrhea during the early 1970s in Oregon among the gay population and even the Oregon Department of Health heavily advertised in The Fountain, a gay monthly magazine, to go get check-ups. Mr. Horton, the Venereal Disease Program Director of Oregon State Board of Health, released the statistics that from 1961-1971 there had been a 600% increase in gonorrhea cases, the eleventh highest in the nation. Bathhouses were dangerous because of the anonymous type of sexual contact between a high number of men. There was always a potential for some form of disease breakout, therefore, it should come as no surprise that AIDS would spread very fast. In Portland, the bathhouse Club Portland remained open, even during the AIDS crisis, and is still in business. There is a sex club in the basement called Zippers beneath Club Portland. The sex club Xes is located on 13th Avenue between Burnside and Washington. There are only three businesses that cater exclusively to gay men in Portland currently. During the 70s there were the following I had come across: Aero-Vapors Bathhouse, Workout Baths, Majestic Hotel Baths (303 SW 12th Ave.), and Olympic Sauna (359 SW Morrison). These are some of the heavily advertised bathhouses, some only known by word of mouth. It is also important to note that the words sauna and health club basically provided the same service, a place for gay men to have sexual encounters.