Mizuno Wave Sky 9 Performance Review

Each year there’s one shoe brand that quickly distinguishes itself from the rest by dropping shoes that redefine how you view the company, and it’s looking like Mizuno is well on the path to taking that crown in 2025.

From the latest iteration of their Neo Vista super trainer to their signature Wave Rider 29, Mizuno has been delivering surprising performance across the board for every kind of runner.

Now comes the Mizuno Wave Sky 9, the company’s max-cushion daily trainer that looks to take a bite of the high-stack market that HOKA has dominated for years but that all shoe companies are trying to expand (see: Saucony reinventing their Hurricane line).

Thanks to the kind folks at Mizuno, pairs of the Wave Sky 9 arrived at the WearTesters Top Secret HQ, and we’re gonna let you know if Mizuno can keep their winning streak going.

What is the Mizuno Wave Sky 9?

Mizuno states:

“This shoe was crafted and enhanced for runners who love a cushioned running experience that almost feels like floating. The midsole was enhanced with NITROGEN INFUSED MIZUNO ENERZY NXT for even better cushioning and energy return. Plus, FOAM WAVE enhances the shoe’s stability without sacrificing softness, and the Smooth Stretch Woven envelops the foot with breathable comfort.”

Based on the spec sheet that Mizuno sent over, the three key features being pushed to consumers are the Smooth Stretch Woven upper, the MIZUNO ENERZY NXT [Editor’s Note: ALL CAPS lets us know Mizuno is serious], and the MIZUNO FOAM WAVE [Editor’s Note: see? super serious] midsole construction.

Cushion

I have a love-hate relationship with thick midsoles and high-stack shoes. While the HOKA Infinite was the shoe that got me running in 2016, it was also a very slow shoe (due in no small part to me being slow). And it led me to explore other high-stack shoes, with many rolled ankles along the way (especially from the HOKA Bondi).

While I’ve enjoyed shoes like the Saucony Hurricane, I approached the Wave Sky 9 with some skepticism given all those past experiences…and I couldn’t have been more wrong.

We saw this in every Mizuno review of late, but the ENERZY NXT foam is something very special, bringing both stability and strong energy return at the same time. That’s very rare in max-cushion shoes for me as a 210-pound runner who finds midsole foam doesn’t like compressing under my feet without making every muscle in my legs work overtime to stabilize me.

Add in the WAVE construction, and you’ve got cushioning that even a heavier runner like me can run in for miles upon miles. I may not set any PRs in the Mizuno Wave Sky 9, but I also won’t give up on my run because of leg fatigue or foot pain. This is a shoe built to keep you moving comfortably for runs of any length, and the cushion setup does that spectacularly.

Unlike the Mizuno Neo Vista 2, I never felt like the chunky slab of ENERZY NXT ever eroded groundfeel. My feet confidently hit the road and treadmill with each step, helping me achieve a much more consistent run without worrying about my gait.

The miles weren’t fast, but they were consistent; and I can’t ask for more in a daily trainer.

Support

As I mentioned above, I don’t think about “max cushion” and “stability” in the same sentence—but Mizuno is here with the Wave Sky 9 to change my mind.

While I couldn’t really pick up the speed to any meaningful level in the Mizuno Wave Sky 9, the shoe remained stable underfoot no matter the pace (or lack thereof during some recent LA heatwaves).

We’ve talked about the WAVE plate, which the company says “disperses energy from impact to a broader area providing a stable platform and a superior cushioning”, and it’s hard to argue with the results.

Like the Wave Rider 29, this shoe is shockingly great in how it absorbs the impact and keeps you going. I took it with me to San Diego Comic Con for 5 a.m. workouts on 13 to 14-hour workdays and never felt an iota of that fatigue on the treadmill—before or after as I embarked on those long days where I clocked 30,000+ steps.

Traction

Like everything else from Mizuno, the X10 outsole is built to eat miles, and I can’t imagine this outsole wearing out for a long, long time.

I’ve taken this out on grass, gravel, and treadmills without any issue.

Upper

This is where we insert the Michael Scott “Well, well, well, how the turntables” reference because just as I said the Mizuno Wave Sky 9 pleasantly surprised me with the thick midsole, it also disappointed me in the upper.

While I’ve praised Mizuno shoes in the past for their more accommodating last shape—something I need with a wider forefoot that would be more appropriate for a Hobbit than a human—the Wave Sky 9 upper surprisingly narrows from the midfoot forward. I felt my toes crush a bit, and while the woven upper does stretch, I could feel myself literally pushing the boundaries of this shoe.

That impacts the lacing experience, which is frustrating because my foot required loosening the shoe enough that I barely had enough lace to achieve a decent knot (though admittedly it never did come undone).

I could get a solid eight miles in the Mizuno Wave Sky 9 before the foot swell made the experience noticeably uncomfortable, but that cushioning made me push through for more miles. The upper got better with each run, but I never could fully avoid that pinching feeling.

And, on an aesthetic level, I wish Mizuno daily trainers had something distinct in their design. Every shoe can’t look like their beautiful Neo Vista, but the Wave Sky 9 looks like a HOKA down to the logo placements.

Is the Mizuno Wave Sky 9 wide foot friendly?

While this standard-width edition is not, Mizuno offered wide men’s and women’s versions at launch, and I imagine I’d really enjoy the experience of that extra room.

This is yet another reminder that it’s always good to try on shoes in-store whenever you can in order to get the right fit.

Is the Mizuno Wave Sky 9 worth $180?

I don’t know.

This is not a do-it-all shoe like the adidas Evo SL (easily the running shoe of 2025) which comes priced at $150, or even the New Balance FuelCell Rebel v5 at an even better $140.

However, it does feel like a premium shoe; and with the price of daily trainers steadily rising, the Mizuno Wave Sky 9 may deliver some sticker shock but sadly not as much as it would have even a year ago.

If you have a more accommodating budget and want a comfortable shoe to keep you moving, the Mizuno Wave Sky 9 is certainly a solid option. It’s an ideal recovery shoe for high-volume runners. But in this economy, that $30 to $40 above the previously mentioned alternatives is a lot to consider.

I can’t tell you that I would recommend this shoe first to someone looking for a max-cushion cruiser, but it would be at least a second or third option.

How to use the Mizuno Wave Sky 9

Though not a top choice for speedwork, the Mizuno Wave Sky 9 is best used as a jack-of-all-trades running shoe that can do a little bit of everything from short, easy runs to long runs.

Mizuno Wave Sky 9 Summary

Though the upper was quite the downer [Editor’s Note: Arune…be better], the Mizuno Wave Sky 9 delivers a top-of-the-line, max-cushion ride and will keep you comfortably moving on long runs.

I would firmly put this in the “win” category for Mizuno but not as enthusiastically as some of their other recent releases. Though truly, that’s a bar that few other shoe companies are reaching this year.

How does the Author Run?

Arune Singh (age 43, 5’11”, 210lbs): Trains daily with functional fitness programming from Deadboys Fitness, founded by Colby “Seth Rollins” Lopez and Josh Gallegos, along with logging 30-40 miles of running per week. He also has a medical history of Sleep Apnea and Myasthenia Gravis, meaning Arune’s focus is on lean muscle mass.

Disclosure

While Mizuno did provide a pair of the Mizuno Wave Sky 9 to facilitate this review, the company had no involvement in this review, didn’t receive an advance look at it, and has not attempted to influence it.