Hi,

I don't believe that the Park Lane has a gym, but they do allow you entry to the Hilton Metropole, which has a small but servicable gym/pool. The Warldorf has a good gym, but the gym opening hours on a weekend leave are a pain (10am opening on a Sat/Sun). I haven't stayed in the Hilton Green Park. The other one to consider is the Olympia. It's got a small but usually quiet gym, but isn't great for travel connections.