Shoe Review: Mizuno Wave Sky 6

The Mizuno Wave Sky 6 is a maximally cushioned everyday training shoe that straddles the line between semi-firm and semi-soft. It feels quite a bit less soft and bouncy than most other shoes in its class, but much softer than most Mizuno shoes. If you enjoyed the Mizuno Wave Sky 5, you’ll likely enjoy this latest version because not too much has changed besides a few key updates.

Fleet Feet reviewers tested the Mizuno Wave Sky 6 during long runs, easy miles and recovery days. Here’s everything you need to know.

More than any other shoe manufacturer, Mizuno is a brand known for its firm, responsive shoes. However, in recent years it has incorporated softer foams, as is the case with the Wave Sky 6. The midsole is a dual-material construction of its resilient Enerzy foam (which is said to be a little bit softer and more responsive than the U4ic EVA foam it replaced) and a soft Enerzy Core foam (which is considerably softer and more energetic than the U4ic material.) The wave-shaped plate made up of those two foams is Mizuno’s way of dispersing energy from impact to provide an engaging ride.

Ultimately, while this is one of the softer shoes Mizuno has ever built, it still feels firmer and more rigid than most competing shoes, like the Brooks Glycerin or the New Balance 1080. The ride feels smooth, thanks to the updated foam package, high heel stack height (36 millimeters off the ground) and a subtle rocker geometry.

“The Mizuno Wave Sky 6 offers a lot of cushion and support without feeling soft or squishy,” Caroline says. “Runners seeking a firm yet highly cushioned shoe to provide reliable comfort and impact absorption will appreciate this one. I like how the top layer of foam feels firmer and more substantial, the bottom layer of foam feels more squishy, and then the rubber outsole ties everything together.”

Fleet Feet reviewers gave the Wave Sky 6 high marks for durability but agreed it felt firm and rigid compared to many other shoes. It can still produce a smooth ride but without the plushness or malleability of some competitors.

While the Wave Sky 6 lacks an energetic pop necessary for faster workouts, it's versatile enough to handle most types of running. This shoe will shine during everyday training, long runs and recovery runs.

“This shoe runs so silky smooth,” says Nate. “It’s balanced and offers a feeling of easy stability for a neutral shoe. There is a great energy routine and bounce in the step. A really solid shoe that can do almost everything.”

“The Wave Sky 6 offers plenty of protection from the impact of the road and is a good fit for people who prefer a firmer feeling shoe,” Kate says. “It cushions your stride without feeling squishy.”

When it comes to developing the next model of a specific running shoe, brands usually take one of two approaches—either they make a major overall or make just minor (usually aesthetic) changes. And when it comes to the Wave 6, there’s not a lot new. The changes are mostly subtle refinements tied to a movement to include more sustainable materials, which we certainly applaud. In fact, in revising this shoe, Mizuno went out of its way to use recycled polyester (made from plastic bottles) in every part of the shoe, including the mesh tongue, interior lining, stretch-woven upper, shoelaces and eyelet reinforcement. There’s also a segment of repurposed leather on the heel and recycled TPU support overlays on the upper.

The biggest change is with the new upper material. This year’s version is similar to last year’s, but it’s slightly thicker and considerably more stretchy than last year’s model, providing a snugger fit. Hidden inside the upper is a more robust heel counter that provides a good amount of rear-foot structure.

“The stretch woven upper nails the perfect balance between securing your foot while having a little stretch and give in there too,” says wear-tester Nate. “Rocking the 2E for my wider, higher instep foot was a perfect fit. No pressure points or anything that rubbed. This shoe fits true to size and really wraps around your foot the way you’d want a premium shoe to.”

Our reviewers appreciated the Wave Sky 6 for its internal comfort, medium-thick gusseted tongue, overall fit and good breathability.

“Mizuno shoes always fit my foot like a glove, and the Wave Sky 6 is no different,” Caroline says. “The triangular shape of the shoe, narrow in the heel and wider in the toe box, seems to fit my foot shape perfectly. The material around my heel, ankle and midfoot is plush and padded while the material over the toe box is super breathable.”

The outsole is identical to the previous version, with segmented sections of Mizuno’s durable and grippy X10 rubber compound interspersed with sections of exposed foam to keep the weight down. Flex grooves in the forefoot add flexibility.

The Wave Sky 6 is about a half-ounce lighter, which is perhaps one of the best changes from last year. It’s still not a super-light shoe, but reducing the weight makes it feel slightly more nimble and spry while still offering a stable connection to the ground.

The Wave Sky 6 is a well-cushioned everyday trainer that will hold up to plenty of miles, giving you a lot of bang for your buck.

“I’m really pleased with this premium everyday trainer,” says Nate. “It’s stable, balanced and bouncy while also feeling durable and supportive. It’s a great shoe to try on at your local Fleet Feet when looking for a new pair.”