Mizuno’s been quietly rebuilding its lineup this year, and the Wave Sky 9 feels like the final piece of that puzzle; a max-cushioned trainer built purely for comfort.
It's designed for runners who want that soft, floating sensation on the road, similar to the ASICS Gel-Nimbus 27.
After running several easy and long runs in them, it’s clear the Wave Sky 9 leans heavily into plush protection and smooth transitions, not speed.
Key specifications
- Price: $180 at Mizuno.com / £165 at Sportsshoes.com (For UK readers)
- Weight: 10.2 oz (289 g) in US (M) 9
- Drop: 6mm (44 mm heel / 38 mm forefoot) - Feels more like an 8mm.
- Upper: Smooth Stretch Woven (recycled material) with gusseted tongue - average breathability.
- Midsole: Dual-layer MIZUNO ENERZY NXT (Nitrogen-infused EVA) + ENERZY foam with Foam Wave geometry
- Outsole: Full-length X10 carbon rubber
Sizing and fit
The fit runs slightly snug with a low-volume toe box, so if you’re between sizes or prefer more space up front, going up half a size is wise.
The woven upper has more structure than stretch, offering a secure lockdown but limited give.
Padding around the ankle and tongue feels luxurious to step into, and although the heel counter sits high, it doesn't put pressure on your achilles and offers very good heel lock down.
Breathability is average; which is fine for cooler days but a touch warm for summer running.
Alastair Dixon
Performance review
The ride is the highlight of the Wave Sky 9.
It’s one of the softest Mizuno shoes I’ve tested, with a feel that’s remarkably close to the Gel-Nimbus 27.
It's plush and protective, yet surprisingly stable, considering the stack height.
The Enerzy NXT top layer brings a gentle, forgiving sensation underfoot, while the standard Enerzy foam below adds a hint of firmness for structure.
The Foam Wave geometry helps blend those layers seamlessly, creating a steady heel-to-toe transition that feels smooth no matter how tired your legs are.
Despite the 44 mm stack height, it never feels wobbly.
Mizuno’s wide base and thoughtful midsole shaping keep the ride balanced, so you can relax into your stride without fighting instability.
At 10.2 oz (for my US(M)9 size), though, it’s not lightweight, if you try to push the pace, the weight shows up quickly but it's a max cushioned cruiser so I wouldn't expect it to be much lighter than this.
It’s happiest cruising through recovery runs or long slow sessions where cushioning and protection matter more than responsiveness.
On the road, that combination of foams gives a gentle rebound that prevents the shoe from feeling dead, even after several easy runs in a row.
The X10 carbon-rubber outsole delivers excellent grip, even on wet surfaces, and adds a touch of firmness that reins in the ultra-soft midsole.
Durability looks strong; after multiple runs, the tread barely shows wear.
The overall sensation is what I’d call “controlled comfort”.
It doesn’t give you the trampoline-like bounce of superfoams, but it soaks up impact beautifully and feels consistent no matter how long you’re out there.
On days when I just want to log miles, zone out, and let the shoe do the work, the Wave Sky 9 is the shoe I am gravitating towards lately.
Alastair Dixon
My verdict
The Mizuno Wave Sky 9 is a premium daily trainer built for comfort above all else.
It’s Mizuno’s softest shoe yet, offering a smooth, stable ride that rivals the ASICS Gel-Nimbus 27 for cushioned miles.
It’s not meant for tempo sessions, it’s a cruiser through and through, but for recovery runs, long easy efforts, or anyone chasing that “float” feeling, it nails the brief.
If you prioritize plush cushioning, durability, and a steady, balanced feel over speed, the Wave Sky 9 is a dependable companion that will keep your legs fresh and your runs relaxed.
If you have any questions about these running shoes, just ask me in the comments below and I'll be happy to help you out! Oh and if you haven't already, go subscribe to my YouTube Channel for more reviews like this one. -Alastair
