Personal trainers often help their clients work out more than the basic muscle groups.
"Trainers sometimes have more of a personal relationship, almost like they become friends," says Berube. "They travel along with everyone else, even helping them with their diets. They work with the chefs a lot of the time."
Leigh agrees: "Celebrities and artists are very fragile, so it's a lot about providing emotional support (and) good life choices. It's about being a big brother or big sister in a way."
Credentials are required, naturally. But compatibility is just as important.
"It's about the energy," Leigh says. "If my client has an interest in horses and dogs and, say, Impressionistic paintings, then I'm looking for someone who maybe has an artist's eye or somebody that's a real animal lover."
Salary: Expect to be paid "$30,000 to $40,000 up to more than $100,000," says Leigh. "Some will take a job as a personal trainer to get a Tom Cruise or Hugh Jackman through a movie ... and some travel with the family." Although Simply Hired puts the national average at $40,000, Berube says, "It depends on who you're hiring. Top trainers can demand whatever they want."