Reese Witherspoon was left aching but in the best shape of her life after being forced to haul a giant backpack around for real while she worked on her new film Wild.
The actress is seen struggling with the backpack - nicknamed Monster because of its size - and even collapsing face down under its weight the first time she tries to lift it in the movie about a woman who hikes the US Pacific Crest Trail alone.
Director Jean-Marc Vallee made sure she upped the realism by telling her the hefty rucksack needed to be packed with heavy weights.
Witherspoon plays Cheryl Strayed, the author of a memoir on which the film was based detailing her solitary trek to overcome her grief after her mother's death, her marriage breakdown and becoming a heroin user.
"I ended up carrying it the whole time and I've never been as strong as I was after making that movie," Witherspoon said.