The Australian actor says he enjoyed undertaking daring stunts and physical challenges when making `Avatar` and found his subsequent movie commitments less fulfilling.

He said: "To be honest I craved a gun and a sword while I was doing `Last Night` opposite Keira Knightley. I didn`t get the same kind of rush from the kissing scenes."

Despite the physical nature of his role as a paraplegic ex-marine in `Avatar`, Sam insists he didn`t do any training or preparation before filming began because he finds exercise "pointless."

He said: "I did nothing. I am not one of these yoga `I only want wheatgrass and blueberry muffins` guys, and I don`t go to the gym, I think it`s pointless. If I pick up something heavy it`s because I`m going to move it."

Despite his lack of fitness preparation, Sam was happy to get involved with the physical challenges on the movie - even when director James Cameron insisted on hurling objects at him.

He explained: "I`m scared of nothing. Every scene is tough but it`s fun and liberating.

"Jim`s very clever at giving you something tactile to react to, so in one scene when a tree explodes, he had a group of people throwing foam and debris at me.

"Jim would hit me with a big rubber stick as I ran by and I would go flying across the room from the shock waves. When you watch it back you see the explosion and then my blue alien flies across the screen - it looks amazing, like I`ve been blown apart.

"Jim hired me because he said I am brave enough to take on any challenge. And I love it, it`s fun."
sections: Celebrities