Mizuno Sky 4 was one of the most cushioned shoes on the market, but it was also one of the heaviest. The Mizuno Sky 5 has been completely reworked and I must say, this is a solid upgrade!
The Mizuno Sky has been a great running shoe for the last four years, but I have found it to be just a bit too much sometimes. There has been a lot of fabric around the ankle and combined with the amount of cushioning available it has been a bit on the heavy side. Despite that it has still been a great shoe that performed better than expected. Now just imagine if Mizuno reworked the shoe and made it lighter. Well, they have done it!
VIDEO REVIEW
Ribbed to perfection
The upper has been completely redesigned and vastly improved in my opinion with a new rib design that is flexible in one direction, but static in the other to improve fit and lockdown.
I think the hold around the heel is close to perfect, and this is one of the most comfortable shoes to have on in my opinion.
The forefoot fits perfectly around my toes, giving a tiny bit of room, but not a lot. It isn’t the most breathable upper out there, but that isn’t normal for a max comfort daily trainer either.
Further back on the shoe you’ll find a gusseted tongue, which is a nice thickness to protect against the laces and a nice height to not to be in the way when you are running. Gusseted means it's attached to each side of the shoe so that it won’t move from side to side when running.
Compared to last year’s version, the heel collar is a little less padded and more breathable. The plushness of the heel collar is closer to the Mizuno Rider 25, though still slightly more padded.
The heel counter is nice and firm, bringing you a lot of stability for those longer runs when your ankles get tired.
Overall, the upper is a nice improvement on the old design, which was a bit too bulky in the back if you ask me. This one hits the spot in a much better way and feels more breathable, and with a much better heel lockdown.
Soft and responsive foam core
Even though there is a lot of updates all over the board, the biggest update is found in the midsole. The Sky 5 keeps its cloud wave design and improves on it to get an even better transition from heel to toe. The small waves are there for added stability and the big wave is there to get a better flow to your running. But this is just the tip of the iceberg.
The biggest news is the addition of the Mizuno Enerzy Core compound, which is significantly softer and has a much higher energy return than previous foams. It is located in the core of the midsole, between the cloud wave layers. Mizuno has added extra thickness in the heel and the forefoot with this foam to again improve the transition and softness from heel to toe.
Not only have they introduced a new foam core, but they have also changed the heel drop of the Sky 5, from 10mm to an 8mm heel drop (the difference in foam under the heel and toes). Which makes the shoe feel a bit more cushioned towards the front.
A lower heel drop, the smaller waves in the midsole, and the firmer heel counter, all make this shoe a nice and stable neutral trainer, perfect for those who just want a bit of stability on their daily runs.
The introduction of the Enerzy Core foam has made the shoe a lot softer in my eyes, especially in the heel and forefoot. This gives you a smooth and comfortable ride but excludes it a little bit from being a shoe for the faster days.
Overall, I find the shoe to be a significant upgrade in the midsole when it comes to comfort. It just feels right when you are running, but I will probably not use it for runs when I want to go faster.
Weight saving across the board
The outsole has strategically placed rubber around the heel and the forefoot, and some exposed foam to save weight. The normal flex groves have been extended to cover the entire foot and make the front of the shoe more flexible. Where there is rubber, there is plenty of it, to ensure a longer lifespan overall for the shoe.
This works well. I haven’t had any issues with running in these shoes regarding grip, and I believe it has enough rubber to last a good while.
Why should you buy it?
What really separates this shoe from the other neutral shoes from Mizuno is the softness. Mizuno Rider 25, which is a fantastic and very versatile shoe, will feel lighter and more responsive on foot.
The Mizuno Sky 5 though is a shoe for people who want more comfort and softness on their daily kilometers. Maybe you have bad knees and like the softer feeling? Or you are a heavier runner who just needs more “cushion for the pushing?” Then this shoe really does work fantastically.
I really like the Mizuno Sky 5 and it’s a great update to an already wonderful shoe. But I must admit that my daily trainer winner from Mizuno is the Mizuno Rider 25, simply because I’m fonder of running in shoes that are lighter and more responsive.
But for those long days where my feet get more beat up, then for sure, I will go for the Mizuno Sky 5.
More inspiration?
Find additional inspiration in our universe right here:
