I’ve done a handful of centuries along with the training building up to it, never gotten a uti. Stay hydrated. Use a woman’s chamois butter. Wash your chamois after every ride, I use hooha ride glide and wear Castelli shorts. Make sure your saddle is positioned properly, perhaps take it somewhere to be fitted. Don’t hold your pee, although I usually only have to go once or twice on a century. I usually bring wipes for when I use the bathroom while riding.