Fit

The Mizuno Wave Shadow length is true to size, with a relatively soft heel cup that cradles the heel well. An anatomical sockliner wraps the foot nicely and provides a sock-like fit with moderate flexibility. Synthetic overlays anchor the uppers to the midsole platform on both sides with a traditional tongue and lace system, and the overlays connect around the back of the heel for additional support. The toebox allows enough room for most of our testers to avoid impingement or hot spots, and the heel collar is low enough to allow full range of motion but secure enough to prevent any slippage.

Comfort

Upper construction consists of three separate fabrics, with a highly breathable material in the toebox area that ventilates easily. The fabric is exceptionally soft, but in the forefoot this fabric creases in an uncomfortable way against the top of the foot during toe-off for some of our testers. The tongue is lightly padded and rests comfortably against the top of the foot, and padding around the heel is enough to hold in place without being too restrictive.

Responsiveness

Mizuno’s Wave technology is designed to direct energy from the rear of the shoe to the front, with varying degrees of stiffness or flexibility incorporated into different models. It also allows motion only in directions where it should go (posterior to anterior), and prevents excess motion where it shouldn’t go (medial or lateral). Combined with resilient U4icX midsole material, the energy return in the Wave Shadow is impressive in our test group. Our reviewers felt that every footstrike had strong push back and bounce, and stayed consistent over high mileage.

Ride Quality

The wave plate on the Wave Shadow is very rigid, and for many of our users this translated into an abrupt slapping feeling on impact rather than a smooth transition of momentum. There is moderate flexibility in the forefoot, but the 8mm drop of the Wave Shadow encourages heel striking, and it’s on rearfoot impact that we found a distinct lack of softness. The full contact rubber on the outsole adds a bit of weight but provides very nice grip and security throughout the gait cycle.

Speed

With lightweight construction and strong energy return, the Wave Shadow is well equipped to let you burn through miles with fast leg turnover and quick ground contact. The question is whether you can tolerate the firm landing platform for a prolonged period of time. If so, this is a recommended shoe for distances up to a marathon; if not, restrict your use to shorter races or training sessions.