The Fitness Center at Hyatt Regency Merida
Hyatt Regency Merida's fitness center is mentioned by professional travelers. Of the 3 professionals that we tracked, 2 referenced the fitness center, such as Lonely Planet and Star Service.
Hyatt Regency Merida 
Lonely Planet
Star Service
Lonely Planet "Not far from the Fiesta Americana bus terminal (another good top-end bet), the 17-story Hyatt offers some of Mérida’s most chic hotel digs, with some 300 rooms, tennis courts, a gym and steam bath, and a great pool with swim-up bar"
Star Service "A whirlpool, steam room and juice bar complement the gym, which is heavy on weights but skimpy on aerobics"
