What Is Cushioning in Shoes? | The Underfoot Padding Explained

Every step you take sends a shockwave up through your heel, into your knees, and along your spine. The cushioning in your shoes is what stands between that force and your body — a layer of engineered foam or gel that compresses on impact and spreads the energy out over a larger area. The best way to understand what is cushioning in shoes is to look at where it lives, what it’s made of, and why more isn’t always better.

For a look at our tested top picks, see our roundup of the cushion walking shoe options ready to buy.

Where Shoe Cushioning Actually Lives

Cushioning sits primarily in the midsole, the layer between the outsole (the tread that touches the ground) and the insole (the surface your foot rests on). Some brands also add cushioning material to the insole itself, but the midsole does the heavy lifting.

How much cushioning a shoe has is usually discussed in terms of stack height — the thickness of the midsole measured in millimeters. A shoe with a 30mm stack feels noticeably softer and more protective than one with a 15mm stack, which will feel firmer and closer to the ground.

• More cushioning = thicker, softer midsole, more impact absorption, less ground feel.
• Less cushioning = firmer ride, closer to a barefoot feel, more responsiveness.
• Support is separate: it governs fit, heel hold, and side-to-side stability, not vertical impact.

A common mistake is conflating cushioning with support. They do different jobs. Cushioning absorbs vertical force; support keeps your foot from rolling excessively side to side.

What Are the Different Cushioning Materials?

Foam technology has evolved quickly, and the material matters as much as the thickness. Each type behaves differently underfoot.

The most common midsole material in modern athletic shoes is EVA — ethylene-vinyl acetate. It’s light, inexpensive, and does the basic job well. If you want something springier that returns energy with each push-off, TPU- or eTPU-based foams fuse material into a springy structure. PEBA is the newer high-performance option that serious running brands increasingly use for its combination of light weight and responsive energy return.

How Much Cushioning Do You Actually Need?

Choose cushioning based on the kind of impact you’re trying to reduce, not on what sounds most plush. Salomon’s guidance frames it simply: pick cushioning that reduces impact during footstrike and eases strain during your activity. If you run on pavement for miles, you’ll feel the difference between a 20mm and a 35mm stack quickly. If you walk short distances or stand on hard floors, a moderate amount of padding usually suffices.

Heavier-impact activities benefit from more cushioning. Minimalist and barefoot-style shoes intentionally strip it away for maximum ground feel. There’s no universal “right” amount — it’s a comfort and performance tradeoff. Runners who want responsiveness often prefer firmer shoes, while those recovering from joint strain lean toward softer, thicker midsoles.

One important caveat from Salomon’s research: cushioning matters most during the first 50 milliseconds of the roughly 250-millisecond support phase of each stride in running. That’s a brief window, and a shoe’s cushioning can meaningfully soften the force arriving in it. But no source claims cushioning prevents injuries outright. A thick sole doesn’t fix poor form or an ill-fitting shoe.

Test shoes based on how they feel during your actual activity, not just how they feel standing still in the store. A shoe that feels great for five minutes can feel dead and flat by mile three.

Is More Cushioning Always Better?

No. Highly cushioned shoes feel soft and protective, but they also reduce ground feel and can slow your foot down. Runner’s World’s analysis of cushioned shoes notes the tradeoff: more foam means more protection from impact, but it often comes with a less responsive ride and a heavier shoe.

Some runners genuinely perform better in firmer shoes because they can feel the ground and react more quickly. Others need maximum cushioning for long distances or joint sensitivity. The right answer depends entirely on your activity, your body, and your preference.

Fit still matters more than foam. A shoe with 40mm of premium foam won’t help if your heel slips or your toes are cramped. Material, density, and geometry all influence how a shoe actually feels on the foot, so don’t judge a shoe’s cushioning by stack height alone.

When you’re ready to compare specific models, our cushion walking shoe picks lay out the top options for everyday wear.