Mizuno Wave Sky 9 Introduction

There’s a Japanese saying called “Hiyaku-teki Hatten” which translates to “Leap-like development”. This is a perfectly fitting term to describe Mizuno’s progress in performance running over the past 2 years.

I can remember my first time running in the Wave Rider 22 many years ago and feeling so underwhelmed by the experience. Mizuno has now been transformed from a traditional, boring brand into an innovative, futuristic one that has unique offerings you can get excited about.

The Mizuno Neo Vista 2 which I tested earlier this year is an absolute pleasure to run in. It has a high level of bounce and energy return that’s rarely seen in running shoes. It’s one of my favourite super trainers to launch this year.

The Wave Rider 29 of 2025 is also unlike any previous Wave Rider version: it has a super soft and modern ride- vast contrast to the firm, flat rides of its predecessors.

The Wave Sky is Mizuno’s max-cushioned trainer and it’s designed to be the plushest, most cushioned trainer in their lineup. It weighs 10.3 oz (292 g) for a men’s US 9. It has gained 0.5 oz (15 g) and it costs $10 more than its predecessor.

Testing Details

• 8 km recovery run at 7:17 per km
• 17 km recovery run at 6:59 per km
• 11 km recovery run at 7:13 per km
• 9 km easy run at 6:32 per km
• 8 km easy run at 6:38 per km
• 16 km recovery run at 6:47 per km
• 13 km east run at 6:35 per km

Mizuno Wave Sky 9 First Impressions

My first run was an 8 kilometre, very slow recovery run. It felt surprisingly firm for a max-cushioned trainer considering how thick its midsole is. It didn’t feel as soft as the Wave Rider 29.

It had a really stable ride without no rockered transitions. It felt like a pure easy day/recovery trainer.

The upper was really comfortable and needed no break-in period. The shoe it reminded me of was the Hoka Bondi 9 which is another max-cushioned trainer that isn’t extremely plush.

Mizuno Wave Sky 9 Upper

The stretch woven upper of the Sky 9 is really unique because it has a reflective pattern that’s woven into it. This makes almost the entire upper light up when the light hits it in the dark.

There’s a lot of padding in the collar and the tongue and it’s not the coolest of uppers- it’s more suited to cool climates than warm ones. The tongue is gusseted so there’s no tongue slide and a stout internal heel counter provides excellent heel lockdown.

The fit is true to size but the forefoot and toe box are narrow so if you’re a wide-footed runner, you’ll definitely need the 2E version. Overall, it feels like a really soft, premium, comfortable upper.

Mizuno Wave Sky 9 Sole Unit

Unlike other brands who have partners, all of Mizuno’s midsole foams are developed by them in their research lab in Osaka. This means that they can tweak them exactly for their purposes.

In the past 2 years, their midsoles have been hit and miss. I felt that the midsole of Mizuno’s Neo Vista 1 was too soft and mushy and that the Wave Rider 29 was also a bit too soft. In the Wave Sky 9, the midsole is more balanced- it’s not overly squishy.

It’s a dual-density midsole with supercritical Enerzy NXT (EVA) on the top and Enerzy (also EVA) on the bottom for stability. This setup gives it an incredibly supportive ride. It also has a wider base than the Wave Sky 8 and it’s one of the more stable max-cushioned trainers.

The Wave Sky 9 is a super max stack trainer. It has 44 mm in the heel and 38 mm in the forefoot (men’s US 9), resulting in a 6 mm drop. It’s great to see Mizuno lowering their drops; 12 mm used to be their signature drop. The Wave Sky is a highly cushioned trainer with deep cushioning that’s not mushy.

The ride of the Wave Sky 9 is firmer than other recent max-cushioned trainers. This includes the Nike Vomero 18 and Vomero Plus, Adidas Ultraboost 5 and ASICS Nimbus 27. My feet don’t sink down into the midsole much- this makes it a good choice for heavier runners. The only firmer max-cushioned trainer is the Hoka Bondi 9.

The Wave Sky 9 is best suited to very slow, easy or recovery runs. While its midsole is not super soft, its substantial weight makes it feel a bit sluggish. There also isn’t a great amount of bounce during transitions so it doesn’t urge you to pick up the pace. For me, it feels most at home doing 6 minutes per km (9:40 per m) or slower paces.

The durability of the Wave Sky 9’s outsole is outstanding. Thick X10 carbon rubber lugs cover all the high wear areas and the exposed midsole foam is also very tough. Traction on wet surfaces is average though because the lugs aren’t aggressive.

Mizuno Wave Sky 9 Conclusions

The Wave Sky 9 is a solid max-cushioned trainer with no weaknesses. It has a really durable outsole, good stability and very deep cushioning. It feels like a premium offering that’s well-built. However, compared to other recent max-cushioned trainers, it lacks some excitement.

It falls into the same category as the Hoka Bondi 9. It has a stable, balanced ride, it’s comfortable but it’s lacking in energy return. If I could change anything about it, I would make its midsole a bit softer and a bit more energetic. It’s not as fun or engaging as the Mizuno Neo Vista 2.

I enjoy running in the Wave Sky 9 but I prefer a stiffer maximalist trainer with a rocker. This speeds up transitions and makes it feel more efficient. I also prefer a midsole that compresses and decompresses more during transitions. If you compare the ride of the Wave Sky 9 to the Nike Vomero Plus (same price), the Mizuno feels a lot blander.

At $180, it’s a bit too expensive for a standard, max-cushioned trainer. It should be at least $15 cheaper. It’s more expensive than the Bondi 9, Triumph 23, Nimbus 27, More v6 and Vomero 18.