A propulsive speed-training partner. Bolder than ever before, the Mach X 2 brings the heat to speedwork. Inspired by the Cielo X1’s race-ready geometry, we combined an extra-resilient PEBA-topped midsole and increased rocker profile for an aggressive toe-off, then extended the Pebax® plate design for enhanced support and propulsion. With an extra-breathable and supportive woven upper and a sleeker collar, this speed trainer keeps things light, cool, and fast for next-level efforts. Best for: Everyday Run Features: Sleek, race-inspired collar Gusseted tongue Lightweight, breathable woven upper Reflective detailing for visibility Highly resilient PEBA foam Propulsive Pebax® Rnew plate Like new, wore two runs ~10 miles.