Hyun Bin's fans might say there is little the actor could do to improve himself. But now that his film "The King's Wrath" is about to be released, he confessed that he worked out so he could look the part.

It's not unusual to get in shape for a part but the star of "Secret Garden" and "Worlds Within" was especially concerned about developing the muscles in his back. And the results have caused plenty of appreciative comments from netizens.

Those muscles have been described as "angry" although fans were not angry to see an image of them.

At a recent press conference for "The King's Wrath," he explained why it was so important to firm up his back.

His motivation came from one line in the script saying that his character did push ups.

"In the script there was one line that read 'Jung Jo does pushups and his back muscles are perfectly detailed.' Because of that one word, 'detailed," I worried about how to create that effect," he said. "I ended up exercising for three months before filming started. After filming began, I maintained the look. I stayed on a strict diet for a month and a half. I exercised every day even on the days we were filming."

Lee Jae Gyu, who directed the film, was impressed with Hyun Bin's dedication but said he never asked him to work that hard.

"I have no idea what Jung Jo's back muscles were like but I think Hyun Bin wanted to show what an intense life the character led, so he devoted a lot of effort to creating those muscles," he said.

This placed some stress on the actor, but he has always been one to push a little harder than he needed to. When asked to describe how he rated himself as an actor, he said he rated about 30 percent out of a 100. He was sure that his fans did not really love him but rather the characters he has played in dramas.

His most beloved character may be that of the arrogant chaebol he played in "Secret Garden." And a favorite scene in that drama was one in which he works out with Ha Ji Won. He is doing sit-ups while she holds his feet. His character is not fond of exercise. Except in this case, every time he sits up, he has the opportunity to get close to her face.

When asked if any drama kiss scenes ever made his heart flutter, he referenced that scene.

"We had to do the sit-up scene many times with our faces so close together and I had a strange feeling," he said on "One Night of TV Entertainment. "It was the first time in my life I did so many sit-ups."

His fans are glad he continued working out. "The King's Wrath" premieres April 30.