Balancing Weight and Durability in Athletic Insole Materials

by | Nov 5, 2024 | Blog, Materials

How INSITE Combines the Best Features of Poured PU and EVA for Optimal Lightweight Performance

 

No matter what sport they’re built for, athletic shoes require insoles that can provide comfort and performance without weighing down the rest of the shoe.  

EVA and PU are two popular athletic insole materials that each offer unique benefits for athletic footwear.  But when every gram counts, which material is best for balancing lightweight performance and durability?  

 

EVA Insoles for Athletic Shoes 

Ethylene-Vinyl Acetate (EVA) is often a popular choice for insole materials because of its lightweight cushioning properties, especially in the world of running footwear.  The structure of EVA can provide good energy return, providing wearers with a responsive underfoot feel that works well on pavement or hard terrain. 

For footwear developers, EVA has the benefit of low density, which keeps the overall weight of the shoe low and making its construction a little more cost-effective. While it cuts down on the weight of the insole, EVA does not have the same durability or compression set as other insole materials.  

This means an EVA insole can flatten out more quickly over time, unlike materials like poured PU, which retain their original thickness for much longer. For this reason, wearers may need to replace their EVA insoles at least once during the life of their shoes.  

A blue poured PU insole imposed over an image of construction workers on a jobsite.

Poured PU Insoles for Athletic Shoes 

Poured polyurethane (PU) insole materials offer a different set of benefits, focusing on durability, shock absorption, and shape support. 

Poured PU foams routinely test better for durability and compression set, meaning they are more likely to retain their thickness for the full life of the shoe, even under heavy use. They can also be engineered for high shock absorption, making them an excellent choice for impact protection and anti-fatigue comfort. 

The dependable structure of poured PU means it can make insoles with form-fitting shape, providing arch support and heel cupping for greater stability. However, the ergonomic features of poured PU sometimes come at the cost of more weight. This is why poured PU is often found in everything from workwear to casual shoes, but it might not always be the first choice for sneakers or lightweight athletic footwear. 

A blue poured PU insole imposed over an image of construction workers on a jobsite.

INSITE Levation™ Ultra-Light PU  

Insoles for athletic and performance shoes need to be lightweight to keep their wearers nimble and responsive. This means that historically, athletic footwear developers have had to sacrifice the durability of their insole materials for lighter materials like EVA.  INSITE is changing the game with a new ultralight PU engineered for insoles for athletic shoes. 

INSITE Levation™ is an advanced formula that can achieve the same durability, shape support, and shock absorption as poured PU, but with up to 30% less weight. 

It also has an energy return comparable to EVA, giving footwear customers the value of a more durable insole without sacrificing cushioning and performance. 

A yellow INSITE Levation insole imposed over an image of a man and a woman running on a boardwalk.

Reduced Weight, Increased Performance 

From soaring on the court to sprinting across the finish line, insoles for athletic shoes require a balance between durable materials that can withstand intense activity without weighing down the shoe.  

Is your brand looking for new innovations that add lightweight, durable materials to your athletic footwear? 

With up to 30% less weight than standard poured PU and longer-lasting compression than EVA, INSITE Levation ultralight PU can help.  

Request a tech pack to learn more about Levation and the rest of our next generation of lightweight insole materials. 

Request a Tech Pack

Ready to redefine gravity for your footwear customers? Request a tech pack from INSITE today, and we’ll send you samples of INSITE’s latest foam innovations.

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