Naomi Osaka is opening up about her postpartum journey and motherhood in a new interview with Glamour.
The tennis star became a mom last July when she welcomed her first child, a daughter named Shai.
"My world turned into a completely different world in one night," Osaka told Glamour.
MORE: Naomi Osaka shares sweet photo update after welcoming her baby girlOsaka, 26, said it was hard recovering after childbirth and isn't shying away about talking about her experience.
"Having a baby completely destroys your pelvic floor," she said. "I was shocked, because I couldn't get up out of my bed. I had to roll sideways, and it was a really long process because, for me, my immediate way of thinking is: To rebuild this I have to do a lot of sit-ups. And I learned that that's totally not what you're supposed to do. You're supposed to do deep pelvic-floor work."
But despite the challenges, Osaka, who is scheduled to play her first match against France's Caroline Garcia at the Australian Open this Sunday, still feels "so strong" today.
"People talk about childbirth, but it's different once you experience it," the 26-year-old said. "I just feel like I can do anything and nothing will bother me, and the pain tolerance has definitely increased a lot from that. I just don't really care about other people's opinions anymore."
Among the choices the four-time Grand Slam champion is sticking to is the decision not to breastfeed her baby girl and to feed her formula instead.
"I watched Serena [Williams'] documentary, and I saw her pumping before she went onto the court to play a match," Osaka said. "I was thinking to myself, 'This might not be the path for me.'"
Osaka said she still worries about being "a good mom" but said she isn't going to let those thoughts hold her back from being the mom she wants to be.
MORE: Naomi Osaka says she had to fight the thought she 'won't be a good mom'"I often worry about if I'm a good mom, but at the end of the day, I realize Shai is my daughter. There's nothing I could do or I want to do that's going to change that, and I just want to be a good role model for her, and I want her to be proud of me," she said.