What is heel drop—and how much do you need?
Ever since the minimalist craze went mainstream, heel drop has become the most important measurement to look for when picking your next road or trail running shoes.
Heel drop is essentially a measurement for how fat a running shoe’s heel feels. It’s short for “heel to toe drop,” often shortened to just “drop.” It's often called "offset," and sometimes called a "ramp angle."
Whatever you call it, it just tells you how much taller the heel is than the forefoot. It's simple math: A shoe with a 25-mm thick heel and a 15-mm thick forefoot will have a 10-mm heel-toe drop. A shoe with a 10-mm-thick forefoot and a 10-mm-thick heel would have a 0-mm heel drop (aka "zero drop").
Here’s why it matters. A shoe with a thick heel demands that you run on your heels—it shoves a wedge of foam beneath your heel which has to hit the ground first. A shoe that’s flat allows you to run on your midfoot—so your entire foot hits the ground at the same moment as your heel. That’s not only the most efficient stride, but it’s also the one that will send the least amount of shock up your leg, reducing your propensity for injuries.
Not long after the minimalist trend began in about 2009, companies began using heel drop as a primary (sometimes the primary) way of categorizing their shoes. Now, if you know you like 4-mm drop shoes, it’s considerably easier to shop than it was five or six years ago.
Here’s a quick reference guide for what to expect from shoes various heel-drops.
0-mm: A flat shoe (a.k.a. "zero drop"). Midfoot or forefoot strikers only. This is the geometry at which your foot is designed to hit the ground, but the feeling is extremely flat for most runners until your body adjust to it.
4-mm: This will feel very flat to most runners, and caters heavily to midfoot strikers. The heel is completely out of the way, with only the slightest hint of padding to forgive accidental heel strikes.
8-mm: This is a compromise zone—midfoot strikers will enjoy this shoe the most, but you’ll start to notice a slightly more prominent heel. Light heel strikers may be able to get away with running in these shoes, and it’s a good place to start if you’re trying to develop a more natural gait.
12-mm: A moderate heel-striking shoe. You will notice the heel. be possible to midfoot strike, but you’ll feel like the shoe’s heel is getting in your way.
16-mm: Heel strikers only. You can’t help but land on your heel. These steeply angled shoes are out of vogue, but still popular with runners who land hard on their heels (natural running be damned!).
(Photo courtesy: Newtonrunning.com)