Breathable, and Workout Friendly. What's the best women's underwear for working out? A million-dollar question with a tried-and-true answer: our Happy Seamless underwear line. Thanks to sleek thermowelded seams and laser-cut leg openings, believe us when we say these are 100% seamless and itch-free underwear. Unicorns of the underwear world, they magically disappear under anything and feel that way too. Wear these to the gym in yoga pants, the boardroom in dress pants, then out for dinner under jeans without a wedgie-worry in the world.