Running shoe drop and cushioning, explained

Running shoe listings use terms like drop and stack height. Here is what they mean.

Heel-to-toe drop

Drop is the height difference between the heel and the forefoot, in millimeters. Traditional running shoes are around 8 to 12 mm. Lower-drop shoes (0 to 6 mm) encourage a midfoot landing and can load the calves and Achilles more, so switch gradually.

Stack height

Stack height is how much material sits under your foot. A high stack usually means more cushioning and a softer ride; a lower stack gives more ground feel.

Cushioning and stability

Neutral shoes suit most runners. Stability shoes add support for runners whose feet roll inward a lot. If you are unsure, a specialty running store can watch you run.

Road vs trail

Trail shoes have deeper lugs and tougher uppers. On pavement, road shoes are lighter and more comfortable.

Replace on time

Many runners replace shoes every 300 to 500 miles, or sooner if the midsole feels flat.