wear whatever's most comfortable for you. i wear whatever i'm already wearing. i mean, yeah, there are panty lines. but i'm hardly at my sexiest at the gym, and not trying to pick anyone up. i'll admit that i look around at other people at the gym, but i've never noticed anyone's panties ever. so unless i'm the only one wearing them wrong, i'm sure you're fine, and no one's going to really care.