| PROS | CONS |
|---|---|
| + 2 foams; 1 with nitrogen + Improved energy return + Softer ride + Decent weight | – Pricey – Dense upper |
Let’s get it out of the way: I didn’t like the previous Wave Sky 8. You could say I hated it. How much? I couldn’t accumulate enough miles in the pair to conduct a review on it. So, when I had the opportunity to review the ninth edition, I had some reservations. But once I learned number nine was getting nitrogen-infused foam and additional stack height, I was intrigued. Find out if the updates were enough to sway my opinion of the shoe, in this Mizuno Wave Sky 9 review.
Mizuno Wave Sky 9 Review
| STACK HEIGHT | WEIGHT | PRICE |
|---|---|---|
| M: 44/38 mm (6 mm drop) | M9: 10.0 oz/283 g W8: 8.4 oz/238 g | $180 |
Intro
It’s understandable if Mizuno doesn’t come to mind when you think of running brands. In addition to running, the Japanese brand makes gear for golf, baseball, softball, volleyball, swimming, soccer, tennis, and even pickleball. Yes, pickleball, despite not being a real sport. I know what you’re thinking: why not just focus on producing the best gear for a few sports instead of risking spreading themselves too thin and producing lesser quality products?
But while you were sleeping on Mizuno, they’ve been having a bit of a renaissance in the running space recently, debuting well-received shoes like the Neo Vista and Neo Zen and the innovative carbon-plated Wave Rebellion Pro super shoe. It’s important to note, those shoes aren’t made in my size, so I despise them.
In addition to the introduction of several new models, Mizuno has continued to refine its flagship daily trainer, the Wave Rider—not to be confused with the On Cloudsurfer (Swiss copycatting frauds)—and the subject of this review: the max-cushioned Wave Sky.
Midsole
The midsole is the shoe’s key update that easily elevates it over its predecessor. Mizuno features what it calls “Foam Wave,” two layers of foam in the midsole. Two foams > one foam, every time. On the top layer of the midsole is U4icX foam—which, contrary to how it sounds, is not the name of one of Elon Musk’s 14 children. This is a firmer foam offering stability without feeling too stiff. Underneath, the midsole is greatly enhanced with the nitrogen-infused EVA foam: ENERZY NXT. This foam has a softer feel and provides excellent energy return.
And if some ENERZY NXT is good, then you know more’s better. Luckily, the stack height increases from a “meager” 41/33 mm in the Wave Sky 8, to now 44/38 mm. Mizuno beefed up the midsole by adding 3 mm of foam in the heel and 5 mm in the forefoot, as the drop decreases slightly from 8 mm to 6 mm.
Ride
It’s hard to believe this is still the Wave Sky. The ninth edition is a lot softer underfoot and has much more forgiving landings. It’s also a hell of a lot more responsive than the 8. While stable, running in the 8 felt like a chore at times. Fortunately, there’s no sacrifice in stability in the 9, even with a livelier midsole and increased stack height.
The nitrogen-infused ENERZY NXT is stellar; I consistently found myself going faster than I intended to on easy runs, even in the heat of the summer. And this has been a “cruel, cruel, cruel summer.” However, the dense upper makes for a sweaty summer run—more on this in a bit.
It felt so effortless to cruise in this shoe, and its lighter 10 oz weight (for a max cushioned pair) sure helps. This easily serves as both an above average daily trainer and recovery day shoe. Outside of the summer, it’s a great long-run shoe, too, offering a comfortable and energetic ride at a decent weight.
The change in heel-to-toe drop felt negligible to me on the run and there are still solid heel-to-toe transitions.
I prefer the ride of the Wave Sky to Mizuno’s Wave Rider 29, as it feels softer, more lively, and is overall a more comfy running experience.
The Wave Sky reminds me of the Nike Vomero 18—plush, comfy, and responsive.
Upper
Up top, there’s a very dense woven mesh upper with a gusseted tongue. Simply put, this upper is not breathable in the slightest. I’m usually pretty forgiving when it comes to uppers and breathability. My entire body is already raining buckets of sweat from each and every one of my clogged pores; a little foot sweat isn’t going to make or break my run. Seriously, if you could see all my cystic face acne, back acne (bacne), blackheads filled with puss, and whiteheads—also filled with puss—you’d understand sweat is nothing new for me.
But the upper on the Wave Sky 9 is something else—and not in a good way. It didn’t help that my first couple runs in the pair were during one of the countless U.S. east coast heat waves this summer. But still, it’s 2025: not having a breathable upper is like not having a moonroof in your car. Tell me you have a moonroof?
I mean, how hard is it to make a breathable upper? Just poke some holes in the top of the shoe and call it a day. There’s also not much space for the top of my foot to breathe with such a low, constricting toe box. This feels like an upper circa 2009. If you transported me back 16 years ago—the prime of my life when I ruled high school—and ripped off this pitiful excuse for an upper and transplanted it on top of another shoe from that year, I wouldn’t think it’s out of place. God, running shoes used to really suck.
Outsole
On the bottom, there’s what Mizuno calls an “X10” outsole—which, again, is not the name of one of Elon Musk’s 14 children. There’s sufficient carbon rubber underfoot that should provide great durability. You’ll have no issues with traction in wet conditions. Hmm, what else is there to say? Well, that’s about it. It’s an outsole, what do you expect?
Weight
Miraculously, despite the stack increase, the Wave Sky 9 only gained a measly tenth of an ounce from the previous edition, coming in at 10 ounces exactly for a men’s size 9 and 8.4 oz for women’s size 8. This is a fabulous weight for a shoe of its nature and I’m shocked the suffocating upper doesn’t weigh it down more.
Price
[sighs] Look, $180 for a shoe without a plate is tough to swallow—or inhale and exhale, in the case of running. Or swallow, if you accidentally ingest a mouthful of gnats on the run. I get that last year’s Wave Sky was priced at $170 and the new model boasts nitrogen-infused foam and additional cushioning, but last year’s edition shouldn’t have been $170. That was one of the more egregious price points for a running shoe in some time. This shoe should be $170. Especially considering a lower price would help Mizuno stand out from the competition and potentially gain more market share in the crowded running space full of heavy hitters.
Aesthetics
This is, perhaps, the one category in which the Wave Sky 8 has the upper hand foot. I miss the bubble-infused-looking midsole; it stood out and was perhaps the one distinguishing feature of the pair. The 9 isn’t a bad-looking shoe but it also won’t blow you away. My “BARITONE BLUE-CITRUS” colorway is…colorful enough and objectively the best of the four rather bland options available. What happened to all the fun colorways brands used to churn out? Is it a cost thing? Take me back a decade ago when crazy colors ran supreme!
Conclusion
A sneaky good upgrade, the Mizuno Wave Sky 9 offers a ride on par with any max cushioned daily trainer worth a damn. It’s a shoe that will likely fly under the radar, but deserves to get some shine from runners looking for a versatile, lively, and lighter pair that can devour miles in comfort. The upper leaves something to be desired, however.
The Wave Sky 9 is available on Mizuno’s website…or anywhere you buy shoes.
Mizuno graciously provided this shoe to me for wear testing. I was not compensated for this Mizuno Wave Sky 9 review and Mizuno did not get an opportunity to see this review before I published.
