I love Nice. I think there is a gym called Versace gym or something like that. It's been a while so who knows if it's still around. Might have been in Antibes (up the road a bit). Hope this helps, if not have a good time anyway.
I lived in paris for many years ,I used to work out at REM GYM,72 rue de Romainville Paris 19 eme(the best in paris) many bodybuilders over there even Serge Nubert he came every days at the same time as me around 1100 am !! it was 8 years ago. by the way any french on this board?