Sophie Turner discovered that the hard way when she booked her first acting gig as Sansa Stark on the show.
"I went through a bit of a dark place, I was not happy with myself," Turner says in Net-A-Porter's EDIT magazine. "I think for me, and for every young girl out there, body image is such a big thing, especially if you are in the public eye. People comment on [your appearance] and... Eugh."
But Turner, who plays Jean Grey in the upcoming X-Men: Apocalypse, managed to escape her funk with exercise.
To prepare for her superhero role, Turner started working with a production-mandated personal trainer, and she says it made all the difference.
"When I was forced to get into shape and eat healthily, my skin cleared up and I felt energetic all the time," Turner says. "It totally changed me."
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"It's probably her best season yet," she told Entertainment Weekly. "It's her really coming into her own. She, this season, really commands the respect that she deserves and she grabs hold of it and she runs with it and it’s really good."