The Fitness Center at Lancaster House
The fitness center at Lancaster House is praised by expert reviewers. Out of 3 publications that we monitored, 3 endorsed the fitness center, like Lonely Planet, Jetsetter and Oyster.
Lancaster House 
Lonely Planet
Jetsetter
Oyster
Lonely Planet "Perks include a free breakfast buffet in the lobby restaurant - named Gatsby's naturally - and a small 7th-floor gym with glass ceiling"
Jetsetter "Any overindulgence can be remedied in the recently renovated rooftop gym, or paired with a sauna session or, for an extra fee, an in-room spa treatment"
Oyster "Alternatively, travelers could consider the Morrison 114 Hotel, which has a chicer atmosphere, but rooms lack kitchenettes and there's no fitness center"
