I've worn them for several rD races, including for my first full marathon. Make sure they aren't brand new so they are a bit broken in and you know they fit properly, aren't too tight, etc. Also if you don't normally wear glasses but plan to wear sunglasses at any point in the race, figure out how you want to arrange all the bands around your ears for maximum comfort. I wear glasses all the time, so I'm used to this, and my fix is to angle the ears slightly forward so the band at my ears is behind the arm of my glasses. Practice at least one run in them to make sure it all works.