Your race: Boston Marathon, 2018. Who needs a weatherproof racing shoe? The majority of the elite field who dropped out before the finish due to miserable weather conditions, that’s who. The Lunarlon sole and Flyknit upper with Flywire filaments for a reliably snug fit is an effective combination in any Nike shoe, but the Flyknit Shield is also water repellent and comes with a high-top cuff to protect your feet against the elements. Despite the extra engineering, the Flyknit Shield is barely a half ounce heavier than the Zoom Fly. Thanks to the shoe wizards at Nike, light running shoes don’t have to leave you scrambling for traction or sloshing your way toward Copley Square when the weather doesn’t cooperate.