I was looking back on recent posts and I noticed nobody responded to this question. I belong to Belair Fitness Center. It is located directly across the street from the St Maarten Medical Center. These are the rates I have from 2017 but they have not changed. You can also buy a card for $100 US. It allows you 10 visits at any time. There is a well equipped gym, large pool, squash courts and Padel courts . They have a Facebook page which would have more information. Hope that helps.