Arnold Schwarzenegger manages to have the same swagger of his action hero heyday in Expendables 2.

But the former governor of California, now 65, admits his body feels the pain far more these days doing the stunts needed for the epic action extravaganza that topped the box office charts this weekend. The sequel made $28.8 million, according to studio estimates out today from box office trackers Hollywood.com. Final figures are expected Monday.

"At 65 your knees are not as forgiving anymore," Schwarzenegger said from the black carpet of the Expendables 2 Hollywood premiere on Wednesday night. "When you do these action movies you have to recognize that it takes longer to recuperate. And you will be sore the next day. But so what?"

Make no mistake, Ah-nuld kicks some bad-guy butt in the movie. But it was mostly the repetition of the scenes that got him.

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"There were scenes where I had to drop down to my knees over and over again," he said. "When you get up each time you really feel it in your knees."

While he might be feeling it in the knees, Schwarzenegger is definitely not looking tired in the face. Despite the lack of facial lines, the star insisted he's never had "Botox. Or any surgery."

"So this is the real thing," he added, pointing to his face.

It could be because the action star admits to having "a funny bone" that not only keeps him looking young , but also allows him to give his one-liners so convincingly.

"If you look at the world seriously, but also in a funny way -- it's easier to deliver the one-liners," said Schwarzenegger. "It has to be part of you. If you are not a funny person, people can write all they want, it's (still) not going to be funny. People have fallen many times trying to be funny on the screen."

He added, "I enjoy the comic relief just as much as the action."