The Fitness Center at Staypineapple, An Elegant Hotel, Union Square
The Alise - A Staypineapple Hotel's fitness center is acknowledged by professionals. Of the 7 publications tracked on TripExpert, 2 mentioned the fitness center, including Gayot and Oyster.
Staypineapple, An Elegant Hotel, Union Square 
Gayot
Oyster
Gayot "Other notable amenities include a small fitness center, meeting space and free high-speed Internet access"
Oyster "The nearby Hotel Adagio offers a good alternative -- while it lacks the sunny charm of the Alise, it adds extras like a fitness center and room service"
