Mizuno Wave Inspire 21 Introduction

The Wave Inspire 21 isn’t a massive upgrade from the Inspire 20 — more of a minor refresh. Mizuno’s biggest claim here is delivering reliable support for overpronators without feeling stiff. They’re aiming to keep up with modern daily trainers from other brands by using updated tech.

Weighing 10.9 oz (men’s) and 8.6 oz (women’s), they are slightly heavy compared to some competitors. Their 12mm heel-to-toe drop favors heel strikers and those who prefer a more cushioned, supportive feel over a “natural” ride.

They will cost you $140. This price is right in the same ballpark as other daily trainers.

Mizuno Wave Inspire 21 First Impressions

Honestly, I wasn’t thrilled when I first opened the box. Mizuno isn’t known for flashy designs, but yikes—the purple and white colorway wasn’t for me. (Maybe I’m biased since those were my high school colors.)

These don’t really double as lifestyle shoes either—definitely more function over fashion here. However, the heel counter immediately stood out—it’s sturdy and well-built.

Despite my initial hesitation (and Mizuno not being a brand I typically gravitate toward), I ended up enjoying these on the run. They felt firm but cushioned, and although they were a bit snug at first, they broke in nicely after a few runs. I would likely go up a half size next time.

My first run in them was an easy 5-mile road jog, and they really exceeded my expectations. The standout was the heel counter—firm, supportive, and stable without feeling clunky. Cushioning in the heel felt great, with solid energy return. If I had to compare, they remind me of the Saucony Guide 17 or Brooks Adrenaline GTS 24.

Mizuno Wave Inspire 21 Upper

The upper is made of recycled engineered mesh, offering good breathability and comfort—especially in warm weather. I tested them during summer and airflow was great.

There’s also generous padding in the heel collar and tongue, creating a plush, locked-in feel. The heel counter is structured without being too rigid, which adds to the shoe’s secure, stable fit.

Mizuno Wave Inspire 21 Sole Unit

The midsole is the heart of the Wave Inspire 21. Mizuno has focused on improving stability and comfort here. The key feature is the Double Fan Wave Plate—designed to offer enhanced control and stability for overpronators. This plate also disperses energy on foot strike, creating a smoother ride.

In the heel, Mizuno uses Enerzy Foam for springy cushioning. The U4ic Foam in the forefoot and midfoot provides a firmer, more responsive feel. Together, these foams deliver a well-balanced mix of cushioning and firmness—stable, but not overly soft.

When looking at the sole it uses Durable X10 Carbon Rubber in high-wear areas. I tested them out on various surfaces and weather conditions, they prove to have great traction. You’ll notice added flex grooves that are located under the forefoot that give you smoother toe-offs.

I tested these out for well over 100 miles and they show almost no to little wear. The durability is another area of the shoe that makes it shine.

Mizuno Wave Inspire 21 Conclusions

The Wave Inspire 21 is ideal for daily training and mid-distance runs. Some may recommend them for longer runs, but

I believe there are better options once you start logging higher mileage. Overall, it’s a reliable, supportive trainer that surprised me—in a good way.