There are a lot of technical features to a pair of shoes, especially running shoes. We depend on our sneakers to get us from point A to Z, over every hill, and around every corner. In this post we’ll walk you around a shoe and highlight some of the key areas you’ll want to get to know.

Anatomy of a Running Shoe: Here’s What All Those Technical Terms Actually Mean

Let’s Start at the Top: The Upper

When you hear or read about the “upper” in a shoe description, it’s referring to the entirety of the shoe that sits on the rubber sole. The following technology may come into play here:

  • Innovations in mesh: varying degrees of tighter or looser mesh weave will hug and hold your feet while avoiding extra friction and the resulting blisters
  • Updates in lacing:eyelet placement impacts how the shoe will lace and a runner can decide to loosen up or lock in
  • Strategic reflectivity; various treatments in overlays, stitching, and logo placement all help with visibility in low-light conditions
  • The upper may also boast single-piece construction or use hot-melt technology to replace traditional stitching for a seamless ride.

Anatomy of a Running Shoe: Here’s What All Those Technical Terms Actually Mean

The Toe Box

The upper also includes a variety of other important footwear zones. The “toe box” of the shoe is the front platform that houses your toes. This is where brands concentrate technology to improve the toe-off stage of your step, which occurs when your heel has left the ground and your toes are transferring force forward. Your legs move into a swing motion after the toe-off. For example, ASICS uses Propulsion Trusstic Technology to support better toe spring, which is built to help push you forward. This is also why your shoe arches up in the front.

The Tongue

Different brands use the tongue to offer new benefits, too. If you see that a shoe has a mono-sock fit, it’s likely that the tongue is built into the upper and the whole thing fits more like a sock. This prevents any movement or distraction from a tongue that slips or moves. Trail shoe tongues are often stitched to protect against picking up gravel, or feature a “lace garage” to hold loose laces and prevent tripping.

The Sockliner

The sockliner lives inside the shoe and gets up close and personal with your feet. Technology in the sock liner can be moisture-wicking or made of memory foam. ASICS uses ComforDry material that cushions, breathes to manage moisture, and is anti-microbial. While this part can make the first feel of a shoe great, sockliners are also removable to accommodate orthotics.

The Heel Counter

As you continue to move toward the back of the shoe you reach the heel counter. In many kinds of running shoes, including ASICS, this is an exo-skeleton that wraps around the outside of the heel. It’s often made of rigid material which holds up against the impact that area of the foot experiences when running. It helps the shoe keeps its shape and stabilizing integrity.

One key heel measurement that experts love to talk about is shoe drop or offset. This is the difference in midsole height from the ground at the heel versus height in the forefoot. For example, if the heel height of a shoe is 23mm and the toe height of the shoe is 13mm, you have a 10mm drop. This is what has been deemed as standard for running; you’ll see a lower number on training or racing shoes (6-9mm drops). Minimalist styles flirt the line with zero drop or a totally flat foot platform.

Moving Downward: The Midsole

The upper sits on the midsole, which sits on the outsole. The midsole is exactly what it sounds like: it’s the layer of technical foam or rubber in between the upper and the part of the shoe that actually hits the ground. There can be multiple densities featured in this area and it’s what impacts the shoe’s ride: its feel of cushioning, neutrality, or stability. ASICS newest technology in the midsole is FlyteFoam™, a much more lightweight and adaptive material than traditional EVA. EVA stands for ethyl vinyl acetate, a foam traditionally used in sneaker construction that creates a cushioning and stabilizing effect but compresses and loses rebound after repeated impact.

Last But Not Least: The Outsole

Anatomy of a Running Shoe: Here’s What All Those Technical Terms Actually Mean

When a shoe store associate or website refers to the outsole, this literally means the outermost layer of rubber on the bottom of the shoe. It’s the last stand between you and pounding the pavement. Features like high-abrasion rubber or trail-specific lugs provide traction for running and off-road shoes alike. Brands like ASICS also build gait guidance technology into the outsole and midsole. When you see a shapely line running through the bottom of your shoe, it’s not just for looks. There is construction there that makes the shoe more or less stable/firm, and split sections also help to lighten the overall weight of the shoe by using less rubber.

We hope taking this lap with us helped to de-mystify at least a few layers of sneaker construction. Check out the cheat sheet below and don’t be shy about asking questions next time you’re shopping. Better yet,or throw some into the Runkeeper Running Group on Facebook—we’re sure you won’t be the only one still wondering!

Be sure to check out the full running shoe lineup on the Runkeeper Store, including the brand new GEL-Nimbus 19! And if you’re still looking to learn more about shoes, we’ve written this guide on pronation and this roundup of Runkeeper employees’ experience with ASICS shoes.

*Why are we only talking ASICS in here?

The Runkeeper proudly joined the ASICS family through our acquisition in March 2016 and we’ve been actively learning about and experimenting with their products ever since—if we weren’t already running in them, that is. We’re proud of the technology and research they put into their shoes, so wanted to look at the very confusing subject of pronation and shoe selection through an ASICS lens. We understand runners look to a variety of brands, though, so check out this piece from the Running Shoes Guru to understand top models across different brands, all sorted by pronation.