BXR

The British heavyweight boxing champion Anthony Joshua is one of the brains—and the muscle— behind this high-end gym and ring in Marylebone. They’ve got loads of famous people on the board, including DJ Mark Ronson and some Victoria’s Secrets models, so it’s the place to go if you like to spot celebs while working out. You have to be a member to use most of the gym, but they do have drop-in classes downstairs. It’s not somewhere I would recommend for a beginner or, shall we say, a less conditioned client.