Running Terms Glossary

Stack height, plantar fasciitis, TPU...the list goes on.  Do these terms strike you as common, everyday concepts? If not, you're not alone - that's why we've created the Running Terms Glossary, your resource for general and brand-specific running terminology.

Running Shoe Terminology

Shoe Last

Physical mechanical part on which the shoe is built that is shaped like a foot.


This stands for “thermoplastic polyurethane” and is noteworthy for its light weight and durability in midsole technology.


Inner part of a shoe that runs on the bottom of the foot. Every shoe comes with a soft and flexible insole and is easily removed in order to replace it with a more durable, supportive insole sold separately.

Hare Hint: Not only do we perform free gait analyses in our stores, we also help find a proper insole from our running specific selections to make your foot the happiest!


The part of the shoe that covers the top of the foot.


The layer on top of the midsole that can sometimes be a different material than the midsole too; not all shoes have a specified topsole as many just have a midsole technology to help with cushioning!


The layer between the outsole and the upper, has a large role to play in what your foot will feel when running and training.


The bottom-most part of the shoe and the part that contacts the ground.

Heel Counter

Small firm insert at the back of the shoe that is used to reinforce the heel cup.

Toe box

Area of the shoe where your piggly wigglies are!


Stands for “Ethyl Vinyl Acetate”, a famous and popular midsole material and is known for its durable and soft nature widespread throughout the industry.

Medial Post

Device in the midsole that is firmer than the rest of the midsole, typically used in the shoe to help correct over-pronating

Types of Running Shoes

Neutral Shoes

Shoes for those people that have a neutral gait. Typically, when analyzed like in our stores from our helpful experts, you will see a neutral gait strike the ground ever-so-slightly on the outside heel, but still near the middle, and push off barely near the big toe, yet still near the middle. In this, the ankle is aligned and therefore quite perpendicular to the ground as the foot goes through the gait cycle.

Stability Shoes

Shoes meant for runners that overpronate, meaning that the foot rolls inward when going through the running motion. A very common occurrence in runners, stability shoes counteract overpronating by having firmer materials in the shoe to bring the foot back to the neutral state while running. Shin splints, knee pain, and plantar fasciitis can occur if a runner needs stability shoes and is not wearing them.

Stability Plus Shoes

A more extreme version of a stability shoe, these are meant for those that severely overpronate, meaning the foot rolls inward while running and walking, while also generally having low to flat arches. Shin splints, knee pain, and plantar fasciitis can occur if a runner needs stability plus shoes and is not wearing them.

Trail Running Shoes

These shoes are meant for more rugged terrain than the everyday road and light paths. Varying from mild and even trails to the aggressive and rocky, these shoes help you explore by having more aggressive outsoles to give you the grip needed while also providing more durability and protection from the trails.

Training Shoes

Built for the gym and all its activities, these shoes generally have your foot lower to the ground because of a lower stack height while having durable outsoles made for more side-to-side movement and lifting weights, all still providing enough cushion for multiple reps and exercises.

Other Running Terms


This is when the foot over-collapses inwardly while going through the gait process, specifically noted by the collapsing of the arch. This is from the shock of impact and the weight pushed down onto the ground not being properly distributed and can lead to injuries if not correctly supported. This type of rotation generally requires stability shoes, or stability plus in extreme cases, while running and walking.


Also referred to as ‘under-pronating’, this is when the foot rolls to the outside (lateral side) of the foot while going through the gait cycle. This type of rotation generally requires neutral shoes while running and walking.

Drop/Heel to Toe Offset

Height difference between the heel and forefoot, measured in millimeters.

Hare Hint: The drop can range anywhere from 0 mm, to upwards of 12mm or more, which is a big difference, make sure to find the right height for you!

Stack height

Measurement of the thickness that is under your foot, often in millimeters

Hare Hint: Lower = more feel for the ground - Higher = more cushioned feeling

Arch height

Categorized by a Low, Medium or High height for the arch of the foot, the arch collapsing or lack thereof is important to note to understand a gait cycle and what type of shoe to wear (neutral, stability, stability plus).

Common Injuries and Issues


Bony bump that forms on the joint of the first big toe, while Bunionettes are smaller bunions that form on the joint of your little toe.

Flat feet

A condition that causes the arch of the foot to flatten and nearly all of it to contact the ground.

High arch

A high arch in the foot is a type that tends to be stable, while also generally requiring a neutral shoe as it will not collapse inward excessively while running (called over-pronating)

Hare Hint: To determine your arch height, get your foot wet then stand on a flat surface where your footprint will show (like a paper bag or cardboard). Look at the footprint and compare to below images: NOTEà can we insert images of three options for what arch could show and descriptions (low, medium, high) here?

Bone spur

Boney projections that develop along bone edges and can occur in the heel for some runners, which is the overall result of inflammation.

Plantar fasciitis

Plantar fasciitis is a usual sign of an unsupportive shoe and is when the plantar fascia, a thick band of tissue that runs across the bottom of your foot from your heel to toe, becomes inflamed. Being properly fitted for both shoe and insole can help alleviate this pain.

Hare Hint: Having arch problems? Come into our stores for a free fitting of not only shoes, but a running-specific insole as well! Our many options of insoles will help support your arch and keep your feet healthy and energized.

Runner’s knee

Pain in the area around your kneecap that can be a result of running, jumping, and general overuse that puts repetitive stress on a knee joint

Shin splints

Pain along the front shin bone, the tibia, due to activity that overworks the muscles, tendons and bone tissue. Rest and ice are good remedies to this relatively common occurrence also known as medial tibial stress syndrome.

IT Band Syndrome

Known as “Iliotibial band syndrome”, this is an overuse injury of the IT band, a ligament that runs on the outer thigh from the top of the hip to the outside of the knee.

Hare Hint: Rollers and massagers, in addition to proper stretching and warmup/cooldown, are a great way to prevent serious IT band injuries.

Definitions Specific to our Brands

DNA Midsole - Brooks

A dynamic midsole cushioning that is designed to adapt to the specific force applied to it, meaning regardless of the many needs and impacts throughout a run or workout, it will provide cushioning unique to every step by taking into account a runner’s distinctive stride, weight, and speed.

ISO (short for ISOFIT technology) – Saucony

A fit and lacing system that includes a soft inner sleeve and a floating support cage with laces that is designed to fit and adapt to any foot or paw while it runs or hops.

EVERUN – Saucony

More durable, more flexible and even less temperature sensitive than EVA, this midsole (and sometimes topsole) stays consistent from the start to end of your shoe’s life. Let this great technology give you exceptional energy return and continuous cushion as you bound along on your run!

GEL – Asics

Cushioning system that absorbs shock during impact and toe-off phases while also flexible enough to allow the foot to move in multiple planes during the gait cycle. Find it in the shoe at the forefoot, rearfoot, or sometimes both for extra cushion!

Zero Drop – Altra

A staple to every Altra shoe, the Zero Drop platform means that the heel and forefoot are the same distance from the ground (a heel-to-toe offset of 0 mm), thus encouraging a low-impact landing and naturally aligning the body’s posture.

BOOST – Adidas

A midsole technology that has extremely tiny, specially formed TPU (thermoplastic plyurethane) capsules molded together that compress under pressure for exceptional comfort, then rebound back to their original shape for a springy feel.

Zoom – Nike

Combining internal fibers with pressurized air bags underfoot, each Zoom shoe is comfortable and quick while also providing a feeling of back fast to propel every runner.


A thick, wonderfully light, dual-density midsole by Hoka that is softer in the heel for a great, cushioned landing and a higher-density cushion in the forefoot for a strong and bouncy push-off.

CloudTec – On

Land soft and push off hard on this outsole technology, as the ‘clouds’ will absorb energy both horizontally and vertically then lock firm to assist in a springy takeoff.

Fresh Foam – New Balance

A midsole technology that is engineered for a comfortable and lightweight feel, as well as having great versatility to adapt to a variety of shoes, feet and running types!

Wave – Mizuno

Sandwiched between the midsole and the outsole, the Wave plates provide cushioning and support, as the shape of the Wave disperses the impact forces by spreading it out while also keeping the foot in the center of the shoe by supporting the arch. The Wave plates are present in every Mizuno shoe and tailored to provide an exceptional feeling in many different types of shoes!