Science
The foam behind every stride
EVA, TPU, PEBA. A plain-language guide to the materials under your feet and what they actually do.
Dr. Priya Shah
· 7 min read
The midsole is the engine of a running shoe. It decides how a shoe feels, how long it lasts, and how much energy it gives back. Most midsoles fall into three families.
EVA: the reliable classic
EVA is light, affordable, and easy to shape. It is the foam in most daily trainers. It compresses faster than newer foams, but it feels stable and familiar.
TPU: durable bounce
TPU foams are made of expanded beads. They are heavier but extremely durable and keep their bounce in cold weather. Great for high-mileage trainers.
PEBA: the race-day foam
PEBA-based foams are incredibly light and return up to 85 percent of the energy you put in. They are less durable, so we use them where speed matters most.
There is no best foam, only the right foam for the run you are doing.
