Reese Witherspoon didn't want to shoot the emotionally raw sex scenes in her new film 'Wild'.

The 38-year-old actress portrays Cheryl Strayed in the movie adaptation of her memoir, 'Wild: From Lost to Found on the Pacific Crest Trail', and she admits it was tough recreating the drug-fuelled lovemaking detailed in the book - which is about Cheryl's 1,100-mile hike of self-discovery along the Pacific Crest Trail.

Reese said: ''I remember thinking, 'I just don't want to do it.' But I had to make a choice as an artist. And Cheryl was brave enough to tell all the parts of her story in her book - the parts that probably made her feel incredibly uncomfortable and would be hard to tell her children and would be difficult to relive. I couldn't honour and do justice to her story by just picking the parts that I was comfortable with.''

The Oscar winner secured the film rights to the memoir in 2012 and was totally committed to bringing Cheryl's story to the big screen, describing the tome as ''one of the most important books I've ever read in my life''.

Cheryl decided to go backpacking at the age of 26 to re-evaluate her life after a succession of devastating events which began with the death of her mother died when she was 22, her becoming estranged from her stepfather, developing a strained relationship with her siblings, taking heroin and getting divorced from her husband.

During filming on location in Oregon and California, Reese admits she phoned her husband Jim Toth in tears, fearing she had taken on too big a task.

In an interview with The Hollywood Reporter, she recalled: ''I call my husband crying. I said, 'I ain't taking this. It's so cold.' I mean, it's really just freezing cold and windy. He said, 'When you optioned this book and decided to make a movie called 'Wild', what did you think it was going to be like?' I was like, 'F**k you!'

Referring to the emotional challenges of Cheryl's story, she added: ''Like one day on set I was getting divorced, and the next day my mother died. And the next day I was having sex with a stranger and shooting heroin.''