My gym has several private bathrooms that only one person at at time may enter. Each one has a sink, toilet and shower.
Is no “locker rooms”. There are cubby holes out side against the wall to put backpacks/carkeys and a place to hang your coat. No one will steal anything because outside there are cameras all up in that place. Your pic is taken when you enter/exit the place. Even stuff they have for sale is left out after hours and if it’s stolen they know.
been a member there for several years...has worked out great.
https://www.anytimefitness.com/
That’s more typical for women’s gyms, you don’t see it in men’s locker rooms, not in my exposure. Maybe I’m just too cheap to pay the membership for a gym that would have that sort of facilities, lol.