Okayama has some great tourist spots such as Ujo castle (Okayama Castle) and one of the top 3 Japanese gardens in Japan; Korakuen. It is convenient for travelers as they are walking distance from the Okayama station from which you can go to Osaka or Hiroshima with bullet trains. For fitness travelers, there is only 1 local gym selling a day pass to travelers in convenient locations and there is 1 hotel with gym room nearby the station. Please check out my recommendations below.
There is only 1 gym that sells a day pass in convenient locations for tourists in Okayama.
Omotemachi Momotaro gym: Open Mon-Fri 10.00-18.00, Sat 10.00-17.00. Closed on Sun. Day pass costs $20 for male and $15 for female per visit. Great facility. See the official gym website.
There are only 3 hotels with gym in Okayama. For fitness facilities, Hotel Abest Grande Okayama is the best option. The location is also great as this hotel is 3 min walk from Okayama station. Also you can walk to Ujo castle and Korakuen garden.
Okayama Koraku Hotel does not have a gym room but it is an old school comfortable 3 star hotel in good location. You can walk to Okayama station in 3 min and popular tourist spots (Ujyo and Korakuen) in 15min, and more importantly to Omotemachi Momotaro gym in 15 min. The convenience store on the ground floor is very useful !