Emily, Cody, and Blake put Mizuno’s max-cushion cruiser through 80 combined miles.
Back to ShoesThe max-cushion world has officially gotten a little out of control, and apparently Mizuno decided they wanted in on the fun. The Sky Prime is a BIG shoe with a ton of foam, a massive platform, and one pretty obvious goal: baby the legs. This isn't trying to be your tempo shoe or some do-it-all daily trainer. This is the shoe you reach for when the legs are cooked, the pace doesn't matter, and you just want to get through your miles feeling comfortable. The big question is whether all that comfort is worth $200.
The Mizuno Sky Prime is your ultimate easy-day shoe. I'm not sure I've felt a softer ride in quite a while. The dual-density midsole debuts Mizuno's Enerzy NXT+ nitrogen-infused foam directly under your foot, giving you an extremely soft ride that doesn't feel totally dead. Under that, Mizuno uses an EVA midsole layer to firm up the ride a touch and offer some stability.
The Sky Prime was perfect for my first miles back after a long run. Not sure if it's my ripe old age of 36 or what, but I've been feeling pretty beat up after some of my long runs. This shoe was exactly what I needed to reduce some of the impact on my feet.
I also noticed that despite the shoe's large size and soft feel, I wasn't going any slower in it. I think the geometry of the shoe really helps with that. It has a subtle but effective rocker shape that gets you into your next stride.
Other than the midsole, the upper is very comfortable, and the traction is solid. Overall, I believe the Sky Prime will be a very durable shoe.
When you talk about the Sky Prime, you have to start with the foam because, well, there's a crap ton of it. And man, does it baby the legs. This is exactly what I want from a true easy-day shoe. It's soft, protective, and made for those days when you want to eat up the miles and not your legs. After a hard workout or a big long run, this is the type of shoe I want to throw on and just cruise. Put it on, slow down, and let the shoe do its thing.
The Mizuno Sky Prime is a very plush, protective long-run cruiser that feels great right out of the box. Unlike the Puma Mag Max 2, which needed some break-in, the Sky Prime immediately delivered a soft, comfortable, and slightly bouncy ride.
The upper is one of the highlights. It's plush and premium feeling, with comfortable padding around the ankle collar and a stretchy knitted tongue that adds a nice touch. It's also noticeably roomier and better fitting than the Wave Sky 9. Breathability isn't its strong suit, but the overall comfort is excellent.
The midsole provides a ton of protection, with 47mm of cushioning in the heel and a 6mm drop. It feels very plush and has a little bounce, but it's not an especially energetic shoe. That makes it ideal for long, slow distance runs and recovery miles. The weight is also surprisingly not too noticeable, especially considering how much cushioning is underfoot.
The outsole uses X10 rubber in the forefoot and heel, and both the rubber and exposed midfoot foam have held up well so far.
Breathability is not great here. I wasn't expecting it to be, but I could feel my feet getting hot after a mile or so. This is often the case with max-cushion shoes.
It's obviously a very large shoe, so if you have big feet (like me), they're going to look even bigger in the Sky Prime. I also know I said above that I wasn't running any slower in this shoe, but sometimes it felt harder to run in. That could totally be because my legs were already beat up while I was running in the Sky Prime, but I think I'm also at a point where running in these 45mm+ shoes can actually feel a bit cumbersome to me.
It was good for recovery runs, but for regular daily miles, I felt this more.
My biggest issue was actually how warm this shoe runs. Mizuno usually makes some pretty breathable uppers, but my feet were definitely cooking a little bit in the Sky Prime. Then there's the size of this thing. To make all that stack stable, Mizuno had to give it a really wide platform, and jeesh... this thing is WIDE. It definitely helps with stability, but the trade-off is that the Sky Prime can feel a little clunky underneath you.
Versatility is also pretty limited. This shoe is made for slower days, and the second I tried picking up the pace, I could really feel its size. Can you run faster in it? Sure. You can also wear cowboy boots to run a 5K, but that doesn't mean you should. The Sky Prime wants to cruise, and I think you're better off just letting it.
The biggest drawback is versatility. The Sky Prime is essentially a dedicated recovery and slow long-run shoe. It feels great at easy paces, but at anything faster it can start to feel mushy. It doesn't have the energetic bounce of something like the Neo Vista.
It's also not the most breathable shoe, which may be something to consider if you run in warmer weather.
The Mizuno Sky Prime is the perfect shoe for what it does. For me, that's slow, easy mileage. I don't think it does anything else particularly great, but I think maybe Mizuno intended it to be that way.
I'd say if you're looking for a big, soft shoe, absolutely check this out. If you're looking for something soft with more versatility, go with something like the ASICS Superblast 3 or Adidas Hyperboost Edge.
If you're looking for a dedicated easy-day or recovery shoe, the Sky Prime is going to be high on my list. It's comfortable, protective, surprisingly stable for the amount of foam underneath you, and it does a great job of babying tired legs. But if you're looking for one shoe that can handle easy runs, long runs, workouts, and faster miles, I think you're going to be disappointed. The Sky Prime knows its job: go slow, be comfortable, and save the legs. And honestly, it's pretty damn good at that job.
The Mizuno Sky Prime is a very comfortable and protective shoe that excels at long, slow distance and recovery runs. It's plush, premium feeling, and surprisingly easy to run in despite its weight. The fit is also a big improvement over the Wave Sky 9, making it a more accommodating option for runners who want plenty of room.
That said, it's a bit of a one-trick pony. The ride isn't especially energetic, but if you're looking for a dedicated recovery cruiser, the Sky Prime does that job really well.
I might catch some heat for this, but at $200, I say yes. It's right around the same price as the two shoes mentioned above and competes with the max-cushioned shoes in this caliber.
This is where Mizuno and I need to have a little conversation because $200 is a lot of money for a recovery shoe. Once we start creeping into that $200 range, I'm thinking more about super trainers—shoes that can give me comfort but also have enough versatility to pick up the pace. If your number-one priority is maximum comfort and you specifically want something to baby your legs on recovery days, I can understand spending the $200. But for everyone else, that's going to be a pretty tough price to swallow. It's a great recovery shoe with premium comfort, but you're definitely paying a premium price for it.
At $200, I think the Sky Prime is a bit expensive for what it does. It does its one job very well, but I would personally rather spend that money on something more versatile, like the Superblast 3, which can handle easy runs, long runs, and faster workouts.
If you specifically want a plush, protective shoe for recovery miles and long, slow runs, the Sky Prime makes sense. But if you're looking for one shoe to do everything, there are better options at this price.
Disclosure: This review reflects Emily, Cody, and Blake’s honest opinions after real-world testing.
