The Spice Girl turned fashion designer opened up to French magazine Madame Figaro and spoke about her do's and don'ts for public appearances.
The mother-of-four is well known for her tongue-in-cheek sense of humour but she appeared adamant about not being seen wearing the casual sportswear.
"You'll never see me on the street in a tracksuit," the 37-year-old told the publication.
"I just love fashion too much to wear a tracksuit! The same goes for Ugg boots. I only wear them at home."
Beckham was apparently spotted wearing a pair of grey trackpants as she left a building in Los Angeles two years ago, but she covered up her face so she wouldn't be pictured in it.
The fashionista also admitted that she loved trawling the internet for new outfits after she put her children to bed.
"I'm a big fan of Net-A-Porter.com. When the kids are asleep, I can travel on this site for several hours," she said.
"I like the idea of quietly shopping at home for clothes and returning them if it doesn't work. This is absolute freedom."