Some leggings were so sheer that you had no choice but to wear underwear underneath them. That created an issue of dealing with panty lines, which really made me feel self-conscious wearing them. Other brands may have offered coverage but going commando under them was just not an option because you could see sweat and discharge if there was no underwear there to protect the pants. This would cause me to have to worry about panty lines or wear thongs underneath these leggings. Wearing thongs brought their own uncomfortable and often embarrassing issues that I needed to deal with. For one thing, the thongs would just always ride up even further, making them very uncomfortable especially after my more strenuous classes at the gym (especially during my spin class). I would also worry about embarrassing infections that we are prone to when we wear items like thongs. It all was just too complicated.