Martha Stewart defends herself after Sports Illustrated Swimsuit cover criticism

Martha Stewart has been forced to stand up for herself after her appearance on the cover of Sports Illustrated Swimsuit sparked criticism.

The 81-year-old businesswoman joined Megan Fox, Kim Petras and Brooks Nader in having a photoshoot for the magazine's annual swimsuit issue, making history as she became its oldest-ever cover star.

Stewart appeared on the cover wearing a white swimsuit with a yellow-gold jacket around her shoulders, and later expressed hope it would act as an inspiration for others.

"I am so thrilled to be on the cover of the @SI_Swimsuit issue!," she wrote on Instagram.

"My motto has always been: 'when you’re through changing, you’re through,' so I thought, why not be up for this opportunity of a lifetime? I hope this cover inspires you to challenge yourself to try new things, no matter what stage of life you are in. Changing, evolving, and being fearless - those are all very good things, indeed."

Stewart has received a lot of praise for her cover shoot, though she also received some criticism as not everyone believed in the authenticity of the photos.

In an interview with Variety after the shoot, Stewart explained: "There are only a few naysayers saying, 'The pictures are over-retouched'."

However, the businesswoman hit back at the claims as she described the pictures as 'incredibly accurate'.

"They’re very good," she said. "I was really pleased that there was not much airbrushing."

Stewart also responded to people claiming that she must have undergone a lot of plastic surgery throughout her years, but she insisted that isn't the case.

"I’ve had absolutely no plastic surgery whatsoever," Stewart said, before sharing some of her secrets to keeping herself fit and healthy.

She said: "I have very healthy, good hair. I drink green juice every day. I take my vitamins. I eat very healthfully. I have very good skin doctors. I’m very careful in the sun. I wear hats and I wear sunblock every single day."

The 81-year-old admitted that she does have 'certain fillers' for 'a little line here or there', but added: "I hate Botox. It’s a weird thing for me. I really and truly don’t do a lot."

Despite having to convince people of her authenticity, Stewart is hopeful about what the cover will inspire.

She explained: "People are now reimagining their future. And that’s what it’s all about. You can call upon the past but reimagining the future for yourself, for your family, for anybody is a very good thing right now, because of the chaos this word is in."