I haven't read the link yet, but Prof Rosa Freedman has written about how she can no longer swim in the Hamptead Ponds. Being Jewish, she can't appear in a swimming costume in front of men who she isn't related to and since TWs are allowed in all 3 ponds, she isn't can't go in any of them. She didn't mention the changing rooms. I'm not a lawyer, but it looks like a possible case to me.