The Fitness Center at Dukes London
The fitness center at Dukes Hotel is mentioned by reviewers writing for major publications. Out of 12 publications that we tracked, 3 recommended the fitness center, including Zagat, Star Service and Fodor's.
Dukes London 
 Zagat
 Star Service
 Fodor's
 "Additional perks include a 24-hour gym, as well as steam and beauty treatment rooms" 
 "Complimentary bottled water, shoeshine, nonstop access to the gym, daily newspapers, and housekeeping mirror the hotel's impeccable low-key manner" 
 "A steam room and gym offer space to work out and unwind, and the Duke’s Health Club provides treatments and massage, which can be booked with the concierge"