Specifications (per Mizuno Japan)
Weight: 6.7 oz (190g)
Stack Height: unknown
Classification: Japanese Racing Flat
The fit is different from traditional US racing flats. The heel, midfoot and forefoot all fit normal to slightly wider for a racing flat. This does NOT have the traditional narrow fit throughout. Instead, imagine the fit of a trainer in a lighter package. This is due to the adjustable fit system and Airmesh upper that hold the foot without being tight. The toe guard initially made the forefoot feel tapered, but with a few miles, it opens up and adapts to the foot. This eventually opened up to give me a perfect amount of room in the forefoot, which is often missed in normal racing flats that have a narrow and tapered toebox. Those with narrow feet may find they have a bit too much room for a racing flat, but that may be fixed by tightening down the laces. For those that want an even wider fit, there is a wide option available through Japanese websites (Rakuten). The fit is fairly true to size as I ordered a size 10 (my normal) and it fit me perfect. There was a tiny bit of extra room at the toes, which I definitely appreciated during the later miles of my recent half marathon
This is a very comfortable shoe for a racing flat. While the ride is firmer, the upper gives the foot plenty of room. The heel counter is somewhat flexible and initially feels very firm, but has relaxed over time. I have not had any issues with pressure on my calcaneus in the heel of the Emperor. The laces do go down a little low and although I thought I would have some extra pressure on my toes from that, I loosened the laces a bit and had no trouble. There was some additional pressure near the top of the foot (close to the talus), but again not tying the laces as tight and trusting the shoe to hold my foot helped quite a bit.
Understand that while the shoe does fit a little wider for a racer, it still will hold your foot secure. The upper is very comfortable, but I would not wear this shoe sockless. Overall the mesh is light, breathes well and I am not surprised I was able to do a half marathon in this shoe with little preparation.
The ride of the Emperor 3 is definitely on the firmer side. This is not a cushioned racing flat, but a firm and somewhat responsive flat meant for longer and faster running. Thanks to the U4ic midsole however, there is plenty of protection. The forefoot flexibility and toe spring keep the ride very smooth during toe off and I was surprised this shoe carried me so comfortably through my first half marathon in a while.
There is a mild heel bevel that keep heel landings smooth and the flexibility in the forefoot does a great job of protecting the calves. The flexible forefoot is balance by a very stiff ride in the heel and midfoot. There is next to no flexibility back there (thank goodness for the heel bevel) but that does provide a stable landing. There is an internal ESS wave plate that does a great job of dispersing shock during rearfoot landings, which helps prevent a harsh feeling during landings. The Mizuno wave plates definitely help with forward transitions and further contributes to the smooth ride of this shoe.
The outsole nubs provide fantastic traction. I have used these on track, road and trail (was surprised by some section of trail during the recent half marathon I ran) and I never lost any grip. On the track, the nubs dig in like spikes and feel great.
The Mizuno Wave Emperor 3 is a fast racing flat but is not the fastest. While billed online as a 5k-10k racer, I would reach for this more for long distance racing up to and beyond the marathon. This shoe has worked well for me during track workouts, but shined most at moderate speeds for half and full marathon races and workouts. The cushioning is firm and protective but not harsh, lending for a more stable flat for longer distances. I did not feel a ton of rebound for good 400 repeats but had plenty of traction and responsiveness for those consistent uptempo efforts (steady state, tempo runs and mile repeats).
THOUGHTS AS A DPT
Mizuno Japan did a great deal of correct things with this shoe. The sole is firmer and the last of the shoe is wider for a racing flat. This gives the Emperor 3 a far more stable ride. Combined with good flexibility only the the forefoot, forward momentum is maintained. I do wish the shoe shoe was full ground contact, but it almost is given the fact that the midfoot shank sits low to the ground.
I find it interesting that the midfoot shanks tapers to the medial side instead of also connecting to the lateral midfoot. From a ligamentous standpoint, the closest ligament in that position is the plantar calcaneonavicular ligament. This complex is actually a series of three ligaments that connect the calcaneus to the navicular bone on the medial side of the foot. It is also known as the spring ligament as it is a major supporter of the medial longitudinal arch and supports the head of the Talus bone. However, this ligament complex stays mostly along the medial side of the foot. The only other structure that makes an almost similar path is the fibularis longus, which travels in a similar path from the lateral rearfoot/midfoot to the medial forefoot. So it could be an attempt by Mizuno to support/imitate those two (or more) structures.
Regardless, I do get the feeling of a stable ride in this shoe. So whether that comes from the wider last, the different shank or the firmer ride, know this shoe will carry you for long miles. Even if you need a little bit of stability.
For those looking for a wider fitting, firmer, long distance racing flat that happens to look really cool, the Mizuno Wave Emperor 3 will fit that bill. The fimer ride, wider last, and comfortable upper make for a stable ride that will keep you going for long fast miles. The grippy outsole and forefoot flexibility make for a smooth ride that handles a variety of paces and the adjustable upper will fit a variety of foot types to a degree. I have very much enjoyed training and racing in this shoe and hope Mizuno considers bringing this shoe to the US. This would be a great addition to their line up that I feel is otherwise missing a racing flat of this caliber. So definitely take a look. For those that are interested, this shoe is available through foreign websites in Europe and Japan (Rakuten) although can also be found on Ebay.
Thanks for reading!
Doctor of Physical Therapy
Kaiser SoCal Manual Therapy and Sport Fellow