Ultrarunner Magda Boulet wore this hat when she won the 2015 Western States 100-Mile Endurance Run. We aren't saying it will help you win a 100-miler, but we also aren't saying it won't! (Hat comes with a drawstring to keep it on your head at high-speeds.) Size is small/medium.
How Long Are You Going
Let us know how you GU for it!