Gymnastics superstar and defending Olympic champion Simone Biles decided to withdraw from Thursday’s individual all-around competition at the Tokyo Games to focus on her mental health.

Biles shared that she was experiencing a mental issue known as the “twisties.”

“They saw it a little bit in practice … having a little bit of the twisties,” Biles told reporters. 

Mental health training expert Robert Andrews, who worked with Simone Biles for four years until 2017, explained to CNBC’s “The News with Shepard Smith” why he’s lauding her decision. 

“The twisties… it’s a symptom of the brain being overwhelmed with too much stress, pressure, and anxiety … in essence, the brain is saying it’s not safe enough for you to do these incredibly difficult skills, and if you do, you’re at serious risk of injuring yourself, so she is wise to listen to her brain and her body,” said Andrews, who is working with Olympic athletes from four countries. 

Andrews told host Shepard Smith that he thinks that social media and the cruelty displayed across platforms plays a major role in Biles’ mental tribulations. 

“If I was talking to Simone, I would tell her to even delete some of these apps from her phone, if that’s what she needed to do, to distance herself from the dark side of social media,” said Andrews, founder and director of the Institute of Sports Performance.

Biles has been replaced by Jade Carey in the all-around final on Thursday.