Kristen Stewart felt like her "whole body rejected" going blonde for 'On the Road'.

The dark haired beauty had to dye her locks for her part as teenage bride Marylou in the road movie about the Beat Generation, but said it was very difficult for her to get used to.

She told US Glamour magazine: "I feel like my whole body rejects it, but it was really important for the character. It was like learning an accent. "I'm starting to carry a bag and even put on lipstick. Very mature for me."

In one steamy scene, Kristen's character is seen romping with two men, and while she finds the raunchy scenes "insane" to watch back, at the time of filming they felt natural.

She said: "It's kind of insane to watch now. I'm like, 'Who is that?' But I think - as every actress says when they do this is - it just felt so right.

"It was so within a different world and so within a different environment that I don't even really feel... I mean, I am personally connected to it, of course, but it is something outside of myself."

'On the Road' is based on the novel by Jack Kerouac, which follows the exploits of who young men travelling across the US in the 40s.