What Is Cushion in Shoes? | Impact Protection Basics

Every step sends a wave of force up through your feet, ankles, knees, and hips. The cushioning in a shoe is engineered to absorb, spread, and reduce that impact before it travels further. Most of it lives in the midsole—the thick layer between your foot and the outsole—and sometimes in the removable insole underneath your arch. Whether you’re logging miles on pavement, working in the garden, or walking the dog, the cushion in your shoes determines how much of that ground impact your body actually feels.

What Cushioning Actually Does

Cushioning’s primary job is shock absorption at the instant your foot contacts the ground. Salomon notes that this matters most during the first 50 milliseconds of the roughly 250-millisecond support phase in a running stride. By spreading that impact force over a longer time and distance, the landing feels less abrupt and the shoe feels softer underfoot. In practical terms, cushioning reduces how much force reaches your joints on every step, which is why cushioned shoes are the default choice for long runs, recovery days, walking, and all-day comfort.

That said, cushion is not the same as support. Cushioning handles vertical compression—how soft or firm the shoe feels when you press down into it. Support controls foot motion and alignment, often through stiffer heel counters, medial posts, or firmer foam densities. A shoe can have generous cushioning while offering minimal motion control, and vice versa. Our tested roundup of the best cushioned tennis shoes walks through several models that balance both.

Common Cushioning Materials and Technologies

Most cushioning comes from foam in the midsole, and the material choice dramatically changes the feel underfoot. EVA (ethylene-vinyl acetate) foam is the industry standard—lightweight, affordable, and versatile. Higher-end shoes increasingly use PEBA or Pebax foams, TPU, ETPU, and nitrogen-infused or supercritical foams that offer better energy return and longer life. Brand-specific systems add their own twist: ASICS uses gel inserts for targeted shock absorption under the heel and forefoot; Nike’s Air units use pressurized gas in sealed chambers; adidas Boost compresses hundreds of foam pellets that deform and spring back.

The thickness of the midsole—measured as stack height—is the simplest indicator of how much cushioning a shoe offers. More foam generally means more cushion, though the foam’s density and formulation determine whether that cushion feels plush or firm. Stack heights under 20mm are typically minimal; anything over 30mm is well into maximal cushion territory.

Does More Cushion Mean a Better Shoe?

Not necessarily. Cushioning is a tradeoff, not a pure upgrade. Thicker midsoles add weight and bulk, which can slow you down on faster runs and make the shoe feel less connected to the ground. Very high stack heights can also reduce stability—the foot sits further from the ground, which some runners find wobbly, especially on uneven terrain or during sharp turns. Runner’s World notes there is no official industry definition of a “cushioned” shoe, which means comfort and fit remain deeply personal. Some people prefer a firm, low-profile ride that lets them feel the ground; others want a cloud-like landing for every step. The right choice depends on your activity, your body mechanics, and your preference.

For walking, gardening, and all-day wear, moderate cushioning (stack heights around 20–28mm) usually hits the sweet spot: enough to protect your joints without making the shoe feel unstable or bulky. For running, the choice depends on distance and pace—plush shoes suit easy and recovery miles, while firmer, lighter models work better for speed work and racing.

FAQs

What is the difference between cushioning and support in shoes?

Cushioning absorbs vertical impact forces and controls underfoot softness. Support controls foot motion and alignment—typically through stiffer materials on the shoe’s medial side or a firmer heel counter. A shoe can be heavily cushioned without being supportive, and a supportive shoe can be relatively firm.

Is more cushioning always better for your joints?

Extra cushioning reduces peak impact forces, which can help some people, but it also increases weight and reduces ground feel. Very thick midsoles may also decrease stability, potentially altering your gait in ways that transfer load to different structures. The best cushion level is the one that feels comfortable and keeps your natural stride consistent.

How can I tell how much cushioning a shoe has?

Check the midsole thickness, often listed as stack height in millimeters by the manufacturer. More foam means more cushion, but the foam type matters too—EVA feels different than PEBA, and a gel or air unit changes the ride. The best test is how the shoe feels when you walk or run in it for five minutes.