For a few months back in 1990, not long after the birth of the Duchess of York's second child, there were some raised eyebrows around Buckingham Palace over the comings and goings of a certain visitor—a musclebound man carrying a gym bag who arrived three times a week. The real skinny? No tryst and, frankly, very little intrigue, says Fergie: "He had me exercising on the back stairs. Later we went out into the gardens, and he had me running up and down mounds in the lawns."

Perfectly appropriate behavior, as it turns out, for a personal trainer, which is what Josh Salzmann is—and then some. With a client roster that has included Helena Bonham Carter, Emma Thompson and Pierce Brosnan, the U.S.-born fitness guru, 41, has earned undying allegiance for helping Britain's most notable celebs whittle away excess through holistic theory, nutrition instruction and hard work. "You're not trying to be some stupid cheerleader," he says of his role. "You have to be intuitive and know when to talk to people and when not to. I think it is therapy, to a degree."

Fergie, 38, who yo-yoed for years (and is now a size 10), agrees. "I was called Duchess of Pork, criticized [for having] a large backside," says the now-divorced royal. "Josh's workouts are why I managed to get through all these stresses over the last nine years. He's my secret weapon."

Others too consider him a vital part of their arsenal. On the wall of the gym at Surrey's posh Wentworth Club, one of the places where Salzmann works, is a movie still from his first celeb client, John Cleese, who used him before his nude scene in '88's A Fish Called Wanda. "This body is more your work than mine," Cleese's inscription reads. "Pity what's happened to it since." More recently, Salzmann spent sessions with Kate Winslet before she headed to Mexico to shoot Titanic. Once, on a day when Salzmann was working at a London men's-only gym, Winslet, desperate for a workout, showed up posing as a Midwestern fitness instructor looking for employment. "I pretended to be doing a job interview, and she put on a mean Cincinnati accent," he says. "But she got her scheduled session."

Salzmann credits his discipline to his years growing up in Pittsfield, Mass., as the son of a rabbi—and also as chubby. "One of the reasons I got into fitness was this image I had of being an overweight kid," he says. As a 12-year-old he began playing sports, eventually becoming co-captain of the Pittsfield High School football team, and by 1974 took second place in a U.S. junior national wrestling competition.

After graduating with a degree in Russian history from Union College in Schenectady, N.Y., Salzmann—who spent time on an Israeli kibbutz during college—served as a conditioning coach for the Tel Aviv professional football and basketball teams. In 1984, along with wife Laura Find-lay, an aerobics teacher with whom he had five children (they divorced in 1995), he moved to London, where a client introduced him to Cleese—and word spread among the celebrated.

These days it's Salzmann's schedule as much as his workouts that keeps him fit. When he's not at the Chelsea townhouse he shares with fiancée Corrine Curtis, 41, a fitness instructor, he writes a column for Britain's Sunday Times, serves as fitness director at London's trendy Bath and Racquets Club and this month will launch his own line of leisurewear.

It's a dedication that his clients find inspirational. "If I wake up and the front pages are full of stories about me, and I'm here working on the bike," says the Duchess, "Josh will say, 'Come on, just keep going. We've been through much worse than that.' "

Susan Schindehette
Simon Perry in London

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