AceShowbiz - Bradley Cooper meditates in freezing temperatures as soon as he wakes up. The 49-year-old actor, whose "Maestro" movie about troubled composer Leonard Bernstein is nominated for seven Oscars including best actor for Bradley who played the conductor, said he doesn't really consider his cold baths a ritual to prepare for roles, but admitted it is helping him stay focused.

"James Nachtwey (a photographer commissioned by the Times) asked me if there are any rituals I do to prepare for a role. I said not really but mentioned that I do cold plunge every morning when I get up," he told The New York Times.

Bradley made the admission as part of a piece by James for the Times that saw him photograph A-listers doing what they loved away from film sets.

The "A Star is Born" actor added about the shoot that saw him captured swinging a hammer in the snow before he took a cold plunge, "We were outside next to a creek, and we looked at each other and thought, 'OK? Let's give it a shot.' It was much colder than the cold plunge I'm used to - and unfortunately, I didn't have a towel or a change of clothes. But we had a good laugh."

Photojournalist James, 75, who is known for his intimate depictions of the front lines in warzones such as like Iraq, Afghanistan, and Ukraine, had never photographed a movie star before, but was sent to do so by the Times for its "Great Performers" issue.

His other shots for the project included Da'Vine Joy Randolph, 37, shopping for fabrics and Paul Giamatti, 56, reading in his favourite second hand book store.

"My work has focused almost exclusively on conflicts and critical social issues, the polar opposite of what might be thought of as celebrity photography," Nachtwey says. But he was intrigued by the challenge, "Art takes talent, but it's also hard work, and exploring what actors practice in their daily lives to strengthen their art would be fascinating."