Selena Gomez just attended her first boxing workout weeks after undergoing a kidney transplant.

On Friday, the singer threw a few punches at the Rumble in New York with her trainer, Noah D. Neiman. Gomez attended his colleague Joe Ferraro’s boxing class. “She killed it. She just came in and went hard. We were all, ‘Okay, that’s what I’m talking about!’” Neiman told People.

The 25-year-old former child star did not seem thrilled with her performance that she told her trainer that she will do better next time. “She said, ‘No guys, I’ll bring my A game next time’ and I was like, ‘What? Look at you, you just had surgery.’ She legit has a new kidney! But she was great,” he said.

Gomez was also wearing her Puma apparel to her workout. The actress announced her partnership with the brand mid-September via a post on her Instagram account. In the snap, Gomez is seen wearing a Puma sports bra that is similar to what she wore at Rumble. She captioned the photo by saying that she’s now an official partner of the brand. Gomez also used the hashtag “pumapartner” in her post.

On Sept. 14, Gomez revealed to her millions of fans that she was MIA for a bit because she underwent a kidney transplant as part of her lupus treatment. She shared a photo with her best friend, actress Francia Raisa, who was her donor. A source told People at that time that Gomez is doing well and has been recovering properly.

“She’s really bounced back more quickly than everyone expected,” the source said. Gomez is also in New York for the filming of the untitled Woody Allen movie. An insider said, “She shows up looking rested and in a great mood and seems to take great care of herself.”

Gomez first opened up about her battle against lupus in 2015. While speaking with Billboard, she said, “I was diagnosed with lupus, and I’ve been through chemotherapy. That’s what my break was really about. I could’ve had a stroke.” A year later, she told the same publication that she decided to go public about her illness because she’s in a much better place. “It was time to use my platform to help,” she said.