The latest update of Mizuno’s plush cushioned neutral shoe, the Wave Sky 4, gets the knit treatment and a redesigned lacing system for a more secure fit. Cushioning remains very high due to the use of Mizuno’s new Enerzy foam combined with XPOP PU and a FOAMWAVE rather than a plastic wave plate. All these elements combined to create a soft trainer ideal for long runs and recovery days. XPOP has a bit more “pop” when you need to speed up a bit. This is a great shoe for piling on the miles.