Lifestyle Health Fitness Nastia Liukin Thrilled to Shut Down Her Skinny Shamers with 'American Ninja Warrior' Success Gymnast Nastia Liukin proved to her skinny shamers that she is strong with her performance on American Ninja Warrior By Julie Mazziotta Julie Mazziotta Julie Mazziotta is the Senior Sports Editor at PEOPLE, covering everything from the NFL to tennis to Simone Biles and Tom Brady. She was previously an Associate Editor for the Health vertical for six years, and prior to joining PEOPLE worked at Health Magazine. When not covering professional athletes, Julie spends her time as a (very) amateur athlete, training for marathons, long bike trips and hikes. People Editorial Guidelines Published on May 30, 2018 12:32PM EDT Nastia Liukin was thrilled to show her strength during an episode of American Ninja Warrior — and to shut down her skinny shamers. The gymnast has five Olympic medals to her name, but she’s still constantly criticized on social media for her slim body type. So after her epic performance on the NBC show, Liukin, 28, spoke out about the body shaming. “Throughout my career (and even more so now) I’ve been criticized for being ‘too skinny’ or been told to ‘go eat a burger’ — trust me I love myself a good burger and fries — so agreeing to do something that required so much physically strength was daunting, especially in front of millions watching on TV,” she wrote on Instagram. “But I took this challenge upon myself and never doubted myself once.” Liukin said that she was a little apprehensive about the strength competition because of her more graceful athletic style. “This challenge was a true test for me not only physically but more so mentally,” she wrote. “I’ll be the first to admit when I agreed to do this I was VERY nervous — especially when everyone kept telling me how gymnasts typically do on this show… but I was never a ‘typical’ gymnast. I excelled more on the artistic, grace and flexibility side of gymnastics. I was NEVER known for my strength.” RELATED VIDEO: Matt Iseman Reveals the Biggest Splurge on His Hawaiian Vacation But not only did Liukin push past her fears and prove she had serious muscles, she raised money for Red Nose Day while learning an important lesson. “Raising $30,000 for children all [over] the world is something that truly touched my heart,” she said. “I also learned a lot from this day, but most importantly, never ever doubt your capability in any challenge life might throw your way.” Tyler Golden/NBC/Getty Liukin has been open in the past about dealing with body shaming, and while some people say she’s too thin now, she was actually criticized for gaining weight after the 2008 Olympics. “People remembered me as this petite blond gymnast in a leotard, and then I go through the normal body changes and people are like, ‘Oh my God. You’re so fat,’ ” Liukin said in February. “I had almost this identity crisis,” she said. “I lost all my self-confidence … I didn’t want to go to events or to dinner or do anything because I was so insecure with myself and my body because of what other people were saying.” Liukin has since learned to ignore the critics. “It’s important to be happy from within,” Liukin said. “Don’t focus on what other people want you to look like or to be or to work on or to say. If I’m happy with my body, and I know that I’m healthy, I need to stop worrying about everybody else. Happiness is strength.”