The Fitness Center at Residence Inn by Marriott Philadelphia Center City
The fitness center at Residence Inn Philadelphia Center City is endorsed by expert reviewers. Out of 4 publications that we tracked, 2 acknowledged the fitness center, such as Frommer's and Gayot.
Residence Inn by Marriott Philadelphia Center City 
Frommer's
Gayot
Frommer's "All together, you have your choice of more than 2,100 rooms, three fitness centers, and 10 restaurants and lounges -- all linked with one another and with the convention center"
Gayot "The hotel also hosts a fitness center and indoor pool, and a spa is located nearby"
