Springy Nike React foam amps up the responsiveness of Nike's gold-standard training shoe set on a durable base that makes it the most stable Metcon to date. Welded overlays add structure without extraneous weight, while signature Flywire cables link the lacing to the sole for reliable, responsive lockdown. An optional Hyperlift insert under the heel fits all Metcon shoes and promotes optimal form for squats, wall balls and thrusters. And the high-traction rubber tread wraps up both sides to give you multidirectional grip for climbing ropes, pushing sleds or sprinting through circuits.