Martha Stewart said she did a lot of Pilates and drank her green juice every day while preparing for the Sports Illustrated Swimsuit Issue

• Martha Stewart made history as the oldest woman on Sports Illustrated's Swimsuit Issue cover.
• Stewart told Insider she did Pilates three times a week to prepare.

Martha Stewart made history earlier this year when she became the oldest woman to grace the cover of Sports Illustrated's Swimsuit Issue.

And Stewart, who recently sat down with Insider to discuss her new partnership with Pure Leaf, is opening up about how she prepared for the iconic shoot.

The 82-year-old lifestyle mogul had two months to get ready, so she said she started going to Pilates three times a week.

"I didn't eat a lot during that time. I was concentrating," Stewart told Insider. "I was doing more Pilates than I was doing eating."

Pilates is a full-body, low-impact workout designed to improve flexibility and strengthen muscles. It's become increasingly popular among celebrities of all ages. David Higgins — who trained the "Barbie" cast during filming — previously told Insider that using Pilates to whip them into shape was a "no-brainer." Higgins also said he doesn't believe in exclusion diets, but he suggested cutting out ultra-processed foods.

Stewart said she also cut out alcohol before her photo shoot, substituting it with iced tea and her daily morning green juice, which she's been drinking for more than a decade and often credits with helping maintain her glowing skin.

"Alcohol is really bad for you in quantity. It's just not the best thing in the world to take in," she said. "But I'm not a big drinker anyway, so it wasn't a big sacrifice."

Stewart said her juice features celery, cucumber, fresh spinach leaves, "a little bit of mint and parsley," a "tiny piece of ginger," a peeled orange, and "you can add a pear if you like."

"If you have my green juice every day, you would just feel great all the time," she said.

Stewart previously told The New York Times that she got her first spray tan for the cover and had to wear nine different one-piece bathing suits during the eight-hour photo shoot.

"All these people were prodding me and talking about 'the girls,'" Stewart told the outlet in May. "I have never called my breasts 'the girls' in my life. I hate stuff like that."

Stewart said it took "a bit of vanity but also a bit of confidence" to say yes to the cover, although she didn't hesitate when Sports Illustrated came calling.

"I thought, 'I can do this. I don't have to give in to convention,'" she told The Times. "If I'm feeling good enough physically and mentally to do such a thing, I'm up for it.'"

Stewart's cover was instantly iconic, and Snoop Dogg told Insider that his best friend was "thirst trapping" during the shoot.

"I mean, I couldn't believe it," Snoop Dogg said. "I had to call her and say, 'Martha, what's gotten into you? Or who's gotten into you?'"

Stewart remains the queen of thirst traps, and she was recently praised after saying she refuses to dress in a certain way because of her age.

"I don't think about age," Stewart told Page Six during the FGI Night of Stars gala earlier this month. "I think people are more and more and more fabulous than they've ever been in their senior years, and I applaud every one of them."

A few days later, Stewart told Insider that she thinks it's important to "wear what looks good on you."

"I loved my little silver coatdress the other day, and I have nice legs so I can show those off," she said. "I wear clothes appropriate for the occasion, hopefully, and clothes that I look good in."