The Fitness Center at Fairmont San Francisco
Fairmont San Francisco's fitness center is mentioned by travel writers. Out of 19 publications tracked on TripExpert, 3 mentioned the fitness center, like Gayot, Star Service and Fodor's.
Fairmont San Francisco 
Gayot
Star Service
Fodor's
Gayot "Guests enjoy access to the on-site Active Sports Club at Nob Hill, offering a fitness center and a selection of spa treatments"
Star Service "Fees are even attached to the gym ($15, $10 for multi-day passes)"
Fodor's "Most guests must pay a $10 day-use fee for access to the gym"
