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Biggest sale of the year is on

Say goodbye to distractions at the gym

Engineered to wear under gym leggings. The Workout Thong's quick-dry fabric is supremely comfortable, with functional seams that stay put, but four-way stretch that moves with you. No chafing, no riding up and minimal VPL. 


So if you have never found the right pair of workout underwear then give Underdays a try. You’ll never look back.


Say Goodbye To Distractions At The Gym


Engineered to wear under gym leggings. The Workout Thong's quick-dry fabric is supremely comfortable, with functional seams that stay put, but four-way stretch that moves with you. No chafing, no riding up and minimal VPL. 


So if you have never found the right pair of workout underwear then give Underdays a try. You’ll never look back.



Over 50+ Rounds Of User-Testing To Create The Perfect Workout Thong

Minimal VPL

Underwear with minimal VPL under leggings.

Sweat-wicking technology

Use of sweat-wicking antimicrobial fabric to keep you fresh & dry– preventing yeast infections. 

Squat-proof

Extra stretch to move with your body but also stays in place— no more digging in or riding up anywhere.

Contrast stitching

Functional yet also stylish.

MINIMAL VPL

Underwear with minimal VPL under leggings.

SWEAT-WICKING TECHNOLOGY

Use of sweat-wicking antimicrobial fabric to keep you fresh & dry– preventing yeast infections. 

SQUAT-PROOF

Extra stretch to move with your body but also stays in place— no more digging in or riding up anywhere.

CONTRAST STITCHING

Functional yet also stylish.

Our Experts Recommended Solutions

🚨 Stock is limited 1853pcs left 🚨

Most popular



Hear it from them

Claire M ⭐⭐⭐⭐⭐

Perfect for under running shorts 

This is such a great thong under my running shorts. I wear thongs fitting hot pants style shorts for running but prefer knickers under them as well. This Underdays thong is perfect, I've now bought 3 and am waiting for more stock to buy a 4th pair. Wash really well, super comfy. 

Kari Ann S ⭐⭐⭐⭐⭐

The best 👌

These are the best underwear I've worn. The material is so soft, the styles are really flattering and they are so comfy. Since finding this brand a year ago I haven't worn anything else! The knickers are also good quality and do not ruin or pull in the wash. So worth the money!

Helen H ⭐⭐⭐⭐⭐

Excellent

As someone who hates things and would never wear them this is a winner. I only tried these after enjoying the brief styles and wanting something to wear under my leggings that wouldn't show VPL. I usually go for seamless shorty styles but they are thin materials and don't last. I don't even feel like I'm wearing a thong, or anything with these. So comfortable. 

Hear it From Them

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