There's a gym at Foyer George Williams on Avenue de Sainte-Clotilde that seems to be open to non-residents. I haven't actually been inside so I don't kow what the facilities are like, but the non-resident price is 90CHF monthly, with discounts for longer memberships. I don't imagine it would be fancy, but if you're OK with basic it may be worth a look.

Thank you so much for your help! I really appreciate it. I contacted the people at exersuisse and they told me that unfortunately, they don't have any cardio equipment. And I will certainly get in touch with Foyer George Williams.

Thanks again!

also looking for a gym in plainpalais myself. im only interested in cardio and i don't expect anything fancy (i.e. no interest in saunas, relaxation rooms or post workout cafés) but decent showers are a must. its a real shame exersuisse only does weights, its so close to where i live!