Like wrapping your foot in a second skin, these women's Flyknit Racer trainers from Nike are all about incredibly lightweight performance. A one-piece knit upper means seamless and stretchy support, with Flywire cables for a locked down, responsive fit that weighs in at an unreal 160g. Sat on a full-length Phylon midsole for agile cushioning, a Zoom Air unit at the heel keeps the foot loaded with springy, responsive energy for swift, light toe-off. And with a racing-specific diamond pattern outsole, you stay gripped whether it's three miles of thirty you're racking up.