The Fitness Center at Claridge's
Claridge's's fitness center is referenced by professionals. Out of 18 reviews tracked on TripExpert, 4 acknowledged the fitness center, like Jetsetter, Star Service and Frommer's.
"The spa is a haven on the top floor, with Sisley facials and a well-equipped gym"
"The discreetly elegant sixth-floor health club and spa has a gym, steam room and treatment rooms, offering beauty and relaxation treatments using Sisley products"
"The building dates to 1894 (when Gilbert & Sullivan’s producer rebuilt it), but modern amenities are installed among the gilded plasterwork and (non-working) fireplaces, the fitness center and spa are huge and up-to-date, and neither floorboards nor exacting staff grumbles upon your approach"
"A refined place to train, the polished wooden floors of Claridge’s fitness center are almost shiny enough to see your reflection, which would definitely make for a novel way to check on your form"