Shoe Outcome

How tall should a running shoe be? Rise of the “SuperStack”

November 1, 2022

n the past decade running shoes have been getting taller, providing new amounts of cushioning and performance for runners and non-runners. With the men’s winner of Ironman Hawaii wearing an unreleased shoe with impressive height, brands are asking Heeluxe, “What is the optimum stack height for a running shoe?” Here we’ll go into the Pros and Cons of the “SuperStack” running shoes.

First up, let’s get our lingo straight. We prefer to isolate Heel Height and Ball Height in a shoe as separate measurements, and some will refer to either of these as Stack Height or simply “stack”. Additionally, there is “drop”, the difference in height between the heel and ball of foot.

Why did brands start making running shoes with taller heights?

It’s all about cushioning and comfort! The maximalist shoes reduced the impact forces of running, particularly in the ball of the foot where we experience 4-7x our body weight with every running stride. In this case “foam is your friend”, with the taller maximalist shoe providing more cushioning than a standard or minimalist shoe. The maximalist design has persisted for over a decade and when combined with new foams the cushioning in running shoes is the softest it has ever been.

How can taller running shoe heights improve performance?

Early maximalist shoes sacrificed propulsion for cushion. But by combining carbon plates to stiffen the shoe, new lightweight foams that have high energy return, and advanced forefoot rocker designs, SuperShoes can improve running performance for marathon runners and even shorter distance runners. There are many theories as to why this happens. One observation from Heeluxe’s lab is that every taller height shoe increases a runner’s stride length at a given pace, allowing the runner to take fewer steps every mile while expending less effort.

However, not all Supershoes work as well as others. The right combination of rocker profile, carbon plate stiffness, sole thickness, and high energy return foam are necessary to produce top performance.

Footwear brands are experimenting with new variations of SuperShoes, including some with forefoot thicknesses over 50mm that we refer to as “SuperStack”. The cushioning and energy return of these shoes are some of the best in our database (of over 1500 shoes).  These shoes produce propulsion forces that are equal to and not better than the best SuperShoes. The SuperStack shoes have some of the highest comfort ratings that we have recording in running shoes.

Are SuperStack running shoes illegal?

IAAF states that track and field shoes must be shorter than 20mm by 2024. World Athletics states that running shoes that are over 40mm tall and have more than one plate are illegal. Shoes like the New Balance SuperComp and Adidas Prime X are illegal based on the World Athletics stack height restrictions. No other running organizations have bans on taller stack height shoes at this time.

Should you make a SuperStack shoe?

There are a lot of runners in the world that will benefit from the cushioning, comfort, and propulsion performance benefits of a SuperStack shoe, and all running footwear brands should consider adding this type of shoe to their product line. When designing and developing these shoes, you’re likely not going to have the optimal version of your SuperStack shoe on the first try. Allow for a longer time to market to ensure adequate time for testing materials and on-body performance.

It is also possible that SuperStack shoes can have benefits outside of running. We are not aware of any testing for SuperStack shoes in hiking, walking, work boots, or multidirectional activities like basketball or football. One consideration when making a SuperStack shoe is the potential trip hazard. Our feet only clear the ground by 1-2cm when walking; a SuperStack shoe with a insufficient rocker could increase the likelihood of a trip and fall.

Is the sky the limit with SuperStack shoes? We’ll keep you posted as more information is available. Until then, please contact Heeluxe if you need help with the testing of your SuperStack shoes.