Our verdict

With 21 editions under its belt, the Mizuno Wave Inspire has earned its place as a value-oriented, support-packed trainer for everyday runs. In our tests, we discovered that its partial plate, rugged outsole, and high drop offer excellent control and durability for heel strikers. However, it’s not ideal for those wanting a lightweight feel or favoring a midfoot-first stride.

Pros

  • Great choice for heel strikers
  • Stable but flexible too
  • Now features Enerzy NXT foam
  • Durable outsole
  • Good fit with gusseted tongue
  • Wide platform for secure landings
  • Great for everyday wear
  • Fairly priced
  • Weighs less than v20

Cons

  • But still feels a bit heavy...
  • Sky-high drop not for everyone
  • Subpar airflow in hot weather

Audience verdict

N/A
Not enough reviews yet

Who should buy

We enjoyed testing the Wave Inspire 21 and recommend it for:

  • Runners who liked the previous version—it keeps the same ride with a better midsole.
  • Heel strikers needing stability without a stiff, clunky feel and who value full outsole coverage.
  • Those wanting more support than average daily trainers without going for overbuilt shoes.

Mizuno Wave Inspire 21

Who should NOT buy

We think the Wave Inspire 21 isn’t the best option for runners with a midfoot or forefoot strike. Its sky-high 12.7 mm drop favors heavy heel landings and works against a forward-leaning stride. Based on our findings, we believe models like the Saucony Guide 17 or Altra Paradigm 7 are far better suited for those with a different footstrike pattern.

Weight is another drawback we noted in the lab. For a smoother, faster and less bulky ride, we recommend exploring the Brooks Hyperion GTS 2 or the Hoka Rincon 4.

Mizuno Wave Inspire 21 parts

Cushioning

Heel stack

With a 38.0 mm heel stack, the Wave Inspire 21 continues to grow closer to the 40-mm threshold—offering generous joint protection for heel strikers, who remain the primary focus of this stability-oriented shoe.

Mizuno Wave Inspire 21 Heel stack
Test results
Wave Inspire 21 38.0 mm
Average 34.3 mm
Compared to 422 running shoes
Number of shoes
22.5 mm
Heel stack
46.3 mm

Forefoot stack

The forefoot measures 25.1 mm, identical to what we found in the Wave Inspire 20 here in the lab. It offers enough foam to handle most runs and falls right in line with what we expect from a road daily trainer.

Mizuno Wave Inspire 21 Forefoot stack
Test results
Wave Inspire 21 25.1 mm
Average 25.7 mm
Compared to 422 running shoes
Number of shoes
13.7 mm
Forefoot stack
37.1 mm

Drop

The Wave Inspire 21 sticks to the formula of its predecessor with a massive 12.9 mm drop. In our view, it's a shoe clearly designed for heel strikers or those who benefit from this kind of high-offset, less-natural geometry.

Mizuno Wave Inspire 21 Drop
Test results
Wave Inspire 21 12.9 mm
Average 8.6 mm
Compared to 422 running shoes
Number of shoes
-0.2 mm
Drop
16.1 mm

Midsole softness

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

Now to the midsole. The Wave Inspire 21 comes with a dual-foam setup combining Enerzy and Enerzy NXT.

Enerzy is Mizuno’s older, durability-focused foam that feels a bit flat underfoot, while Enerzy NXT is a fresh-and-snappy upgrade that we’ve already tested (and loved) in models like the Neo Vista. We measured the Enerzy layer at a firm 26.6 HA, which fits the shoe’s goal of providing a steady-and-controlled ride rather than cloud-soft landings.

Mizuno Wave Inspire 21 Midsole softness
Test results
Wave Inspire 21 26.6 HA
Average 20.8 HA
We use an average of four tests. The photo shows one of those tests.
Compared to 348 running shoes
Number of shoes
5.9 HA
Midsole softness (soft to firm)
35.0 HA

Secondary foam softness

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

The secondary foam is the one that hits the ground first and is a variation of Enerzy NXT that's also adjusted to boost stability and limit side-to-side movement. We measured it at 19.3 HA, which adds a touch of plushness, though the ride still feels on the firmer end.

Mizuno Wave Inspire 21 Secondary foam softness
Test results
Wave Inspire 21 19.3 HA
Average 23.7 HA
We use an average of four tests. The photo shows one of those tests.

Midsole softness in cold (%)

We put the Wave Inspire 21 next to our mochi ice creams for 20 minutes and found that it got 19% firmer. Not a bad outcome!

Mizuno Wave Inspire 21 Midsole softness in cold (%) freezer
Test results
Wave Inspire 21 19%
Average 25%
Compared to 347 running shoes
Number of shoes
1%
Midsole softness in cold
63%

Insole thickness

We found that Mizuno added a 5.4 mm EVA-based plush insole to boost the cushioning in the Wave Inspire 21.

Mizuno Wave Inspire 21 Insole thickness
Test results
Wave Inspire 21 5.4 mm
Average 4.4 mm
Compared to 418 running shoes
Number of shoes
1.5 mm
Insole thickness
7.3 mm

Rocker

We discovered that the Mizuno Wave Inspire 21 stays true to its heritage by skipping an aggressive heel bevel or forefoot rocker, something we truly value in a market crowded with rockered running shoes.

Mizuno Wave Inspire 21 side

Both curvatures are modest and non-intrusive, letting the high-drop geometry do the forward-driving work for heel strikers.

Mizuno Wave Inspire 21 Rocker

Plate

New

The Wave Inspire 21 sticks to its signature setup with a partial plate tucked in the heel to control landings in that zone. It's one more reason why we're certain this shoe is made for rearfoot strikers.

We will also use this photo to show the deep lateral decoupling groove in the heel, which allows the rearfoot to compress independently and improves torsional flexibility too. Paired with the Wave Plate, it balances impact control with a stable, well-cushioned ride.

Mizuno Wave Inspire 21 Plate

Size and fit

Size

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Width / Fit

We crafted a gel mold of the shoe to discover how it fits, and we discovered that the interior of the Wave Inspire 21 offers solid space for those with broader feet, especially during longer runs.

In our first measurement, we registered 98.4 mm of width, which clearly beats the average and makes this shoe a wide-foot-friendly option with a generous midfoot platform.

Mizuno Wave Inspire 21 Width / Fit
Test results
Wave Inspire 21 98.4 mm
Average 95.3 mm
Compared to 177 running shoes
Number of shoes
88.5 mm
Width / Fit
102.4 mm

Toebox width

We performed a second measurement in the big toe area, and this time it came up as an average 73.5 mm. That’s not hyper-generous like the Topo Atmos, but still a comfort-ready fit for most runners.

Mizuno Wave Inspire 21 Toebox width
Test results
Wave Inspire 21 73.5 mm
Average 73.5 mm
Compared to 177 running shoes
Number of shoes
66.7 mm
Toebox width
83.3 mm

Toebox height

We finished the trifecta of measurements regarding fit with the toebox height.

There’s plenty of upward space with a vertical clearance of 30.9 mm, a design ideal for runners who hate pressure, especially around the big toenail.

Mizuno Wave Inspire 21 Toebox height
Test results
Wave Inspire 21 30.9 mm
Average 27.3 mm
Compared to 176 running shoes
Number of shoes
22.4 mm
Toebox height
34.1 mm

Traction / Grip

Traction test

New

Whether the roads are dry or wet from yesterday's rain, you can rely on the Wave Inspire 21 for great grip on both.

To mimic running on wet road, we applied a force of 500N to the shoe's forefoot (because that's where the push-off happens) at a 7-degree angle. Brushing the shoe's outsole against a slab of wet concrete, we recorded a solid friction score of 0.50. This is a solid result for a road running shoe.

Test results
Wave Inspire 21 0.50
Average 0.46
Compared to 216 running shoes
Number of shoes
0.11
Forefoot traction
0.83

Outsole design

New

The X10 outsole features full-length rubber coverage in a segmented layout. The forefoot and rearfoot include diagonal lugs separated by thin flex grooves. A deep central channel runs from heel to midfoot, aiding compression and movement plus exposing the blue Wave Plate.

For those seeking durability, this is a great option, as most brands are reducing outsole coverage. However, it will likely take a toll on weight.

Mizuno Wave Inspire 21 Outsole design

Stability

Lateral stability test

During our test runs, we discovered that the WI21 delivered is stable as a table—especially for heel-first landings. Rather than relying on old-school stability elements like firmer inserts, Mizuno used its signature Wave Plate, which adds structure without making the shoe overly stiff.

Torsional rigidity

Indeed, we twisted the Wave Inspire 21 and measured a 3/5 torsional rigidity—more in line with neutral daily trainers than stability models. Mizuno achieved this by using a heel-only plate, keeping the rest of the shoe pleasantly flexible.

Test results
Wave Inspire 21 3
Average 3.4
Compared to 401 running shoes
Number of shoes
1
Torsional rigidity
5

Heel counter stiffness

The heel counter leans closer to classic stability designs with a firm 4/5 rating. It’s not uncomfortable thanks to the generous padding, but runners who prefer highly-flexible heel counters might find it a bit too rigid.

Test results
Wave Inspire 21 4
Average 2.9
Compared to 385 running shoes
Number of shoes
1
Heel counter stiffness
5

Midsole width - forefoot

One simple way to enhance stability is by widening the midsole, giving the foot a more grounded feel on each landing. That’s exactly what Mizuno did with the Wave Inspire 21, reaching a broad 118.1 mm in the forefoot.

Mizuno Wave Inspire 21 Midsole width - forefoot
Test results
Wave Inspire 21 118.1 mm
Average 114.2 mm
Compared to 423 running shoes
Number of shoes
102.2 mm
Midsole width - forefoot
126.9 mm

Midsole width - heel

The same design logic applies to the heel, which measures a generous 94.0 mm—clearly wider than average. This was key, as we believe that 9 out of 10 runners using this shoe will be landing on their heels.

Mizuno Wave Inspire 21 Midsole width - heel
Test results
Wave Inspire 21 94.0 mm
Average 90.6 mm
Compared to 423 running shoes
Number of shoes
70.8 mm
Midsole width - heel
106.6 mm

Flexibility / Stiffness

New

Any shoe aiming for all-day versatility needs a bit of flex—otherwise, it won’t feel right for hitting that 10K steps goal around town. Luckily, thanks to its short-length Wave Plate, the Mizuno Wave Inspire 21 delivers with a 14.5N result in our bend test.

Mizuno Wave Inspire 21 Flexibility / Stiffness
Test results
Wave Inspire 21 14.5N
Average 14.9N
Compared to 224 running shoes
Number of shoes
4.0N
Flexibility <> Stiffness
28.5N

Weight

One thing that really stands out while running in the Wave Inspire 21 is that it doesn’t feel lightweight at all—mainly because of its full-length rubber coverage. Still, its 10.1 oz (286g) isn’t bad at all, showing a 5% improvement over its predecessor and closing the gap to the average.

Mizuno Wave Inspire 21 Weight
Test results
Wave Inspire 21 10.1 oz (286g)
Average 9.3 oz (265g)
Compared to 423 running shoes
Number of shoes
5.6 oz (159g)
Weight
12.6 oz (357g)

Breathability

Instead of using a classic engineered mesh, Mizuno went with a jacquard mesh that doesn’t feature any large ventilation holes. That immediately raised questions for us about how breathable this shoe would be.

To get a clear answer, we used our smoke machine and, unfortunately, the result was slightly below expectations. It scored a 3/5, which isn’t a major issue for most runners, but we were hoping for stronger airflow.

We then placed the upper over a bright light and quickly noticed that there wasn’t much space for air to escape. Because of this, we believe it might get a bit warm on heat-wave summer days.

Mizuno Wave Inspire 21 microscope

The upper feels solid and the material is comfortable against the foot, yet the micro-openings we spotted under our microscope appear too small to truly help with ventilation.

Mizuno Wave Inspire 21 mesh

We also checked the padding. There’s a satisfying amount in both the tongue and heel, giving the shoe a soft-cushioned feel.

Test results
Wave Inspire 21 3
Average 3.8
Compared to 352 running shoes
Number of shoes
1
Breathability
5

Durability

Toebox durability

The absence of large ventilation holes turned out to be an advantage in our Dremel-based durability test, as we gave the Wave Inspire 21 a 3/5. It’s not an award-winning result, but still solid for everyday miles.

Test results
Wave Inspire 21 3
Average 2.6
Compared to 286 running shoes
Number of shoes
1
Toebox durability
5

Heel padding durability

The same story unfolded with the heel padding durability—this Mizuno outperformed the average and earned a solid 4/5. Once again, there’s no reason to be concerned about early signs of wear.

Test results
Wave Inspire 21 4
Average 3.3
Compared to 281 running shoes
Number of shoes
1
Heel padding durability
5

Outsole durability

We were also pleased with the outcome when we tested the outsole using the Dremel: only 0.9 mm of damage. Staying below 1.0 mm usually means there's enough durability, especially for a shoe with generous coverage.

Test results
Wave Inspire 21 0.9 mm
Average 1.0 mm
Compared to 264 running shoes
Number of shoes
0.0 mm
Outsole wear
2.0 mm

Outsole thickness

To be absolutely sure the Wave Inspire 21 holds up over time, Mizuno added 4.5 mm of rubber beneath the foam. For us, that feels a bit much—this shoe already leans heavy, and something closer to 3 or 3.5 mm would've struck a more reasonable balance.

Mizuno Wave Inspire 21 Outsole thickness
Test results
Wave Inspire 21 4.5 mm
Average 3.3 mm
Compared to 419 running shoes
Number of shoes
1.0 mm
Outsole thickness
6.1 mm

Misc

Price

The market is red-hot right now, and any overpriced daily trainer usually struggles to sell. That’s why we found that the Wave Inspire 21 held its ground without a price bump, maintaining a value-focused position.

Test results
Wave Inspire 21 $140
Average $147
Compared to 423 running shoes
Number of shoes
$60
Price
$285

Reflective elements

We found a few small reflective elements on the upper, but we believe Mizuno could step it up with a more hi-vis design.

Test results
Wave Inspire 21 Yes

Tongue padding

The lacing system on the Wave Inspire 21 reflects a no-nonsense approach with simple punched eyelets and flat shoelaces deliver a secure fit without gimmicks.

Mizuno Wave Inspire 21 shoelace

The tongue keeps the same structure from the previous version with 6.9 mm of padding, and we understand why. We tested it and found that it offers a confident lockdown without resorting to a super-thick, overcushioned slab that might feel plush at first but often overwhelms later.

Mizuno Wave Inspire 21 Tongue padding
Test results
Wave Inspire 21 6.9 mm
Average 5.9 mm
Compared to 420 running shoes
Number of shoes
0.4 mm
Tongue padding
14.2 mm

Tongue: gusset type

The tongue is partially fixed to the sides—just enough to enhance the lockdown with a more secure, movement-free feel.

Mizuno Wave Inspire 21 Tongue: gusset type
Test results
Wave Inspire 21 Both sides (semi)

Heel tab

The heel tab uses a tall, pull-friendly collar—similar to what we’ve seen in some Hoka models—which can be easily grabbed to help slide your foot in with less effort.

Mizuno Wave Inspire 21 Heel tab
Test results
Wave Inspire 21 Extended heel collar

Removable insole

The stock insole removes effortlessly, making it easy to replace with your favorite insert. There’s enough space in the upper to accommodate most alternatives without causing any tightness.

Mizuno Wave Inspire 21 Removable insole
Test results
Wave Inspire 21 Yes