--- title: "What is a Running shoe made of?" description: "A knitted synthetic upper over a foam midsole and rubber outsole — about a dozen materials, all glued together. Every component, the material it uses, and the constr" url: https://atoneplace.net/made-of/running-shoe/ site: "At One Place" --- # What is a Running shoe made of? **What is a Running shoe made of?: A knitted synthetic upper over a foam midsole and rubber outsole — about a dozen materials, all glued together.** A running shoe contains a dozen or more polymers bonded with solvent adhesives into a laminate that cannot be economically separated, which is why fewer than a per cent are recycled into new shoes and why several manufacturers are trying single-material designs. The 2016-2020 arrival of thick PEBA midsoles with carbon plates measurably improved marathon times and forced World Athletics to cap stack height at 40 mm for road racing. For most runners the far more consequential fact is unglamorous: the evidence that any particular shoe category prevents injury is weak, and comfort in the shop is about as good a predictor as anything the industry has produced. ## Component by component *Every material is a choice, and the third column is the constraint that drove it.* | Part | Material | Why that material | | --- | --- | --- | | upper | engineered polyester or nylon knit mesh with thermoplastic overlays | A single knitted piece can be dense where support is needed and open where ventilation is, with no seams to rub. | | midsole | EVA, TPU or PEBA foam, sometimes supercritically foamed | It is the entire cushioning system; the compound and the thickness decide how the shoe feels far more than anything else. | | plate | carbon fibre or nylon, in racing shoes | A stiff plate in a thick soft foam stabilises the compression and stiffens the toe, reducing the work the calf does. | | outsole | carbon or blown rubber in patches at the heel and forefoot | Rubber is heavy, so it is applied only where wear actually happens rather than across the whole sole. | | insole and heel counter | moulded EVA sockliner and a thermoplastic heel cup | The counter holds the heel in place; without it the foot slides and the fit does nothing. | ## Other clothing and kit objects - [Velcro (hook and loop)](https://atoneplace.net/made-of/velcro/) — Two nylon tapes — one of stiff hooks, one of soft loops — copied directly from burdock burrs. - [Leather](https://atoneplace.net/made-of/leather/) — Animal hide whose collagen has been chemically stabilised so it cannot rot — usually with chromium salts. - [Gore-Tex](https://atoneplace.net/made-of/gore-tex/) — A stretched PTFE membrane whose pores are far too small for a raindrop and far too big for a water vapour molecule. - [Denim](https://atoneplace.net/made-of/denim/) — A cotton twill with indigo-dyed warp and undyed weft — the dye sits on the fibre surface, which is why it fades. - [Helmet](https://atoneplace.net/made-of/helmet/) — A hard shell to spread the blow over a crushable polystyrene foam liner that is destroyed by one impact. - [Bulletproof vest](https://atoneplace.net/made-of/body-armor/) — Many layers of woven aramid or polyethylene fibre that catch and deform a bullet; rifle threats need a ceramic plate. - [Zip (zipper)](https://atoneplace.net/made-of/zipper/) — Teeth of metal, moulded acetal or nylon coil on a polyester tape, forced together by a wedge inside the slider. - [Synthetic leather](https://atoneplace.net/made-of/synthetic-leather/) — A polyurethane or PVC skin on a textile backing — including the plant-based ones, which still need a plastic binder. - [Shoe sole](https://atoneplace.net/made-of/shoe-sole/) — A rubber outsole for grip, a foam midsole for cushioning, and increasingly no clean way to separate them. - [Wetsuit](https://atoneplace.net/made-of/wetsuit/) — Closed-cell neoprene foam full of nitrogen bubbles, faced with stretch jersey — the gas insulates, not the water. - [Life jacket](https://atoneplace.net/made-of/life-jacket/) — Closed-cell foam or a CO2-inflated bladder, in a nylon cover — rated in newtons of buoyancy, not in size. - [Button](https://atoneplace.net/made-of/button/) — Usually cast polyester resin; the good ones are shell, nut or horn, and you can tell by touch and temperature. ## Common questions ### What is a Running shoe made of? A knitted synthetic upper over a foam midsole and rubber outsole — about a dozen materials, all glued together. ### What is the upper of a Running shoe made of? Engineered polyester or nylon knit mesh with thermoplastic overlays. A single knitted piece can be dense where support is needed and open where ventilation is, with no seams to rub. ### What is the midsole of a Running shoe made of? EVA, TPU or PEBA foam, sometimes supercritically foamed. It is the entire cushioning system; the compound and the thickness decide how the shoe feels far more than anything else. ## Related pages - [Velcro (hook and loop)](https://atoneplace.net/made-of/velcro/) - [Leather](https://atoneplace.net/made-of/leather/) - [Gore-Tex](https://atoneplace.net/made-of/gore-tex/) - [Denim](https://atoneplace.net/made-of/denim/) - [Helmet](https://atoneplace.net/made-of/helmet/) - [Bulletproof vest](https://atoneplace.net/made-of/body-armor/) - [Zip (zipper)](https://atoneplace.net/made-of/zipper/) - [Synthetic leather](https://atoneplace.net/made-of/synthetic-leather/) - [Pencil](https://atoneplace.net/made-of/pencil/) - [Tennis ball](https://atoneplace.net/made-of/tennis-ball/) - [Banknote](https://atoneplace.net/made-of/banknote/) - [Golf ball](https://atoneplace.net/made-of/golf-ball/) - [Paper](https://atoneplace.net/made-of/paper/) - [Glass](https://atoneplace.net/made-of/glass/) ## Sources - Typical range compiled from manufacturer specifications — At One Place (/about/)