There are plenty of local and international chain fitness clubs with multiple locations all over Philadelphia [1], including Bally’s, Sweat, and Philadelphia Sports Club. There is an extensive network of YMCAs that differ in amenities and cost, but tend to be cheaper than private clubs.
The two fitness clubs listed here, Rittenhouse Fitness Club [2] and 12th Street Gym [3], are unique offerings in a sea of perfectly nice, if sometimes pricey, well-equipped and easy-to-find chain establishments.
Links:
[1] http://www.moon.com/destinations/philadelphia/discover-philadelphia
[2] http://www.moon.com/destinations/philadelphia/arts-and-leisure/recreation/other-recreation/fitness-centers/rittenhouse-fitness-club
[3] http://www.moon.com/destinations/philadelphia/arts-and-leisure/recreation/other-recreation/fitness-centers/12th-street-gym