If you’ve been following Serena Williams’ post-retirement fitness journey, you know she’s been dropping pounds fast. Now we know how the tennis legend shed 31 pounds to get her incredibly chiseled abs.

During an appearance on the Today Show on Aug. 21, Serena reveals she’s been using a GLP-1 medication for over a year to lose weight, in partnership with health care company Ro, where he husband Alexis Ohanian is an investor and serves on its board.

“I was on and off (the medication) and now completely on,” she says. “It was a really good decision I had to make for my life, you know, I tried everything.”

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The Olympic champion says the decision to use the drug stemmed from having a hard time dropping the baby weight following the birth of her two daughters, Alexis Olympia, born September 2017, and specifically her second child, Adira River, born in August 2023.

“This all started after I had my (first) kid,” she continues. “As a woman, you go through different cycles in your life. … No matter what I did — running, walking, I would walk for hours because they say that’s good, I literally was playing a professional sport — and I could never go back to where I needed to be for my health. Then, after my second kid, it just even got harder. So, then I was like, OK, I have to try something different. That’s kind of what led to this whole journey.”

Despite using GLP-1 meds, Serena put in hard work like the professional athlete she is. The 23-time Grand Slam winner hit 20,000 steps a day and also tried being vegan, vegetarian, and put herself on a strict high-protein diet, she told the outlet.

“A misconception is that it’s a shortcut,” she explains. “As an athlete and as someone that has done everything, I just couldn’t get my weight to where I needed to be at a healthy place — and believe me, I don’t take shortcuts.”

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The big question: Will the Olympian return to the tennis court after retiring in 2022? Williams doesn’t completely rule it out, but she misses the competition.

“I think there’s a part of me that will always miss tennis, because it was something you do for your entire life. From the day you remember, you always had a goal. Then one day you wake up, and that’s not your goal anymore, and it’s a huge change,” she said. “But at the same time, I have so many wonderful memories, you know? I’ve had so many great times, and yeah, I can always take solace in that.”

Serena might not be coming out of retirement any time soon, but she will be in the stands to cheer on her older sister Venus Williams, who is currently competing in the U.S. Open after a 16-month break last season due to a knee injury.

“I will definitely be cheering her on and rooting her on the whole way,” Serena said. “Pretty excited for what she’s doing it’s pretty remarkable.”