Veteran actor Arnold Schwarzenegger, who is reprising his role as Terminator in the fifth installment of the eponymous franchise, finds action scenes taxing, but promises to surprise the audience with interesting twists in "Terminator: Genesis".

The actor was merely 37 when he first played the character in the classic 1984 movie. Now at 66, he found the action scenes taxing on his body, but he says the story still has a relevant context.

"The way that the character is written, it's a machine underneath," Schwarzenegger told MTV News, reports contactmusic.com.

"It's this metal skeleton. But above that is human flesh. And the Terminator's flesh ages, just like any other human being's flesh. Maybe not as fast. But it definitely ages," said the actor.

Talking about the action scenes, he said: "Sometimes it does get more difficult when you're 66 years old and doing this kind of action, versus when you're in your 30s or in your 40s.

"'Terminator' deals a lot with time travel, so there will be a younger T-800, and then what that model does later on when it gets reprogrammed, and who gets a hold of him. So it will be all kinds of interesting twists in the movie, but I feel so good."

Schwarzenegger wasn't a part of the fourth Terminator movie released in 2009, but he doesn't plan to miss out on any more of them.

"I was upset that I couldn't be in the fourth Terminator, because I was governor (of California) So they did the fourth one without me, it made me cry a little bit. But I did say, 'I'll be back,' so now I'm back again and it's going to be really terrific," he added.

The movie will release July 1, 2015.