Foxes thinks sportswear mixed with vintage "works really well."
The 25-year-old singer - who is the new face of Adidas - believes teaming her bright crop tops with pieces from a previous era creates an "odd" but unique look.
Speaking to Grazia magazine, she said: "I love mixing sportswear with vintage as well. It's the oddest match but it works really well. There's something I love around the uniqueness of adding vintage to sportswear.
"My mum has a vintage store in Brick Lane so I use a lot of her ideas and her clothes.
"On the Adidas shoot today I had some denim shorts and mom jeans going on, and was mixing them with all the bright coloured sportswear."
Meanwhile, the brunette beauty - whose real name is Louisa Rose Allen - is fronting the campaign for Adidas' new Energy Boost trainers and admits she wears them everywhere because they finish off any outfit.
She explained: "I love the fact that you can match your sports bra to the shoes - I'm going to be doing that all the time now. There's something exciting about going to work out when your outfit matches."
However, one place Foxes won't be wearing the snug shoes is on the red carpet.
Asked if she would wear the Energy Boost trainers on the red carpet, she replied: "I think no because I wear them every day and what's nice about the red carpet is that you want to feel elegant, almost like you scrubbed up to your best. I guess you can sort of be a more polished version of yourself."
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