Not that its hard to get into any hotel's gym. Just carry an "expired" room key and knock on the door if need be. Roll your own PP benefit if inclined. Most Marriott gyms are fairly deserted IME.

I once stayed at a SHS whose gym was under construction (in CT). They told me they had an arrangement to use the gym at a RI nearby. Naturally, the RI claimed they knew nothing about it but let me in...