The Olympics may be over, but the spirit of sport will still be running strong at the Materials Show in Portland – and so will we. OrthoLite will be there with our complete lineup of insole formulations designed to support every footwear category, from fashion to high performance.

In honor of sport, we’re putting the spotlight on one of our heritage categories: running.

For the past several years, industry conversation has focused on macro innovations: higher stack heights, propulsion plates, super critical foams, and evolving geometries. These architectural shifts have reshaped how shoes perform.

But the runner’s experience and the shoes comfort and performance is, and always will be, ultimately defined at the interface: where the foot meets the shoe, mile after mile. The true foundation of running isn’t just the structure around the foot. It’s the system directly beneath it.

OrthoLite has been helping shape that foundation since 1997. From high-mileage daily trainers to carbon-plated race-day models, our insoles have logged hundreds of millions of miles under runners worldwide. Through every training block, tempo session, and finish-line breakthrough, one truth has remained constant: real performance starts underfoot.

Spotlight On: Rebound

First, a few facts about rebound – the responsive sensation runners feel the moment their foot hits the ground. It’s one of the most noticeable ride characteristics in a performance running shoe, and it’s also a measurable performance metric.

• Technically, rebound refers to energy return. Every footstrike sends force into the midsole foam. Lower-rebound foams absorb more of that energy and dissipate it, while higher rebound foams return a greater portion of it to the runner, contributing to a more responsive ride which helps drive forward motion.
• High-rebound materials don’t create new energy. Instead, they minimize mechanical energy loss during compression and release. In a well-engineered running shoe system – working together with geometry, plates and outsole design – this improved energy return can enhance stride efficiency, reduce muscular demand over long distances, and support better performance outcomes.
• But rebound isn’t just physics, it’s also perception. A foam that measures high in rebound in the lab may feel very different on the road depending on the runner and the shoe’s overall construction. Factors such as stack, height, plate stiffness, rocker geometry, and individual gait mechanics all influence how that energy return is experienced. For one runner it may feel highly propulsive; for another, more controlled and stable.
• No foam can achieve 100% energy return. Some energy will always dissipate as heat during impact and compression. That balance matters—extremely high rebound without sufficient control can feel unstable or overly bouncy.
• Temperature also plays a role. In warmer conditions, foams typically feel softer and more compliant. In colder environments, they can feel firmer and slightly less responsive.
• Which leads to an important design question for footwear developers: How do you preserve the intent of your midsole platform all the way to the runner’s foot?

We’ve got you covered. OrthoLite X Series is a range of high rebound, performance formulations that offer customized elasticity to dial in performance and feel for your insole application.

OrthoLite® X Series™: We’ve Got You Covered

The OrthoLite® X Series is a family of high-rebound performance formulations engineered to help footwear designers tune underfoot elasticity and maintain the energy profile of their running platforms. You’ve likely spent countless hours engineering your midsole geometry, foam compound, plate integration, and rocker profile for a specific run experience. X Series insoles are designed to protect and amplify that intent rather than dampen it.

Think of the X Series as precision-tuned rebound for the top line of your shoe. With four formulations and elasticity ratings ranging from 25 to 40, X Series insoles help support:

• Cleaner energy transfer from midsole to foot
• Reduced top-line energy loss
• More consistent underfoot feel over time
• A smoother, more responsive ride sensation
• High level breathability and moisture management

And like all OrthoLite formulations, they remain lightweight, washable, breathable, and highly durable, maintaining cushioning and rebound performance over the life of the shoe.

Because if the midsole is your engine, the insole shouldn’t be the brake. Unlock the full potential of your running platform with OrthoLite X Series: X25 · X35 · X40 · X55