Anyone else with autonomic dysfunction?

I'm looking for some ideas on ways to exercise horizontally or as recumbently as possible. Because of my Sjogren's Syndrome, my eyes, skin, and membranes don't do too well with repeated chlorine exposure in a pool, but I have purchased a recumbent bike since I can no longer use my treadmill like I used to and will be restarting some CV conditioning using the bike. There is also a well-stocked YMCA gym if I want to commit an hour of driving each time but am not sure what would be found in a typical gym that won't involve a mostly vertical position. Anyone else on here with POTS or some other form of autonomic dysfunction who's managed to find effective forms of cardio?