Time for some high heel intelligence! A new study found that high heels can permanently damage your feet and legs – even when you’re not wearing them!

Australian researchers analyzed one group of women who wore high heels 5 days a week, and a group that mostly wore flats.

Researchers attached sensors to the women’s legs, and studied the way they walked in high heels, sneakers, and barefoot.

The result? No matter what type of shoe frequent high heel wearers wore, they walked in the same high heel flexed-foot way. Even when they walked barefoot. Causing them to have drastically shorter calf muscles than women who wore flats. Lead researcher Dr. Neil Cronin says that shorter calf muscles strain your leg and foot muscles. And every time high heel wearers walk in any type of shoe, even your comfiest pair of furry slippers, your risk of injury shoots up for everything from sprained ankles to ligament tears.

This doesn’t mean you need to give up your Jimmy Choos forever. Instead, experts suggest limiting your high heel time to twice a week to prevent permanent foot damage.