Making a super shoe midsole that delivers high energy return, consistent performance, sustainability and a longer lifespan

Midsoles are the beating heart of performance footwear. They carry the load, absorb the impact, and return the energy that drives every stride. But, for all their importance, most midsoles fall short – literally. The foam breaks down. Rebound fades. Performance drops off just when athletes need it most.

The norda™ 005 was designed to change that. Built in collaboration with Envalior and powered entirely by an Arnitel® Performance foam midsole, the 005 aims to go farther, last longer, and perform better – in all weather and trail conditions. It’s the first plate-less super shoe for trail running that doesn’t sacrifice energy return, protection or durability.

Let’s look at what really matters in a midsole:

• Energy return
• Lifespan
• Consistent performance
• Sustainability

High Energy Return

Every ounce of energy counts when you’re climbing elevation at mile 47. High energy return in a midsole means less wasted effort and more propulsion with each stride – critical for ultramarathon distances and variable terrain.

The Arnitel® Performance Advantage

Arnitel® TPC delivers over 80% rebound—among the highest of any foam used in high-performance footwear. Compared with traditional TPU, Arnitel® Performance provides up to 20% more rebound and lower hysteresis, meaning less energy is lost and more is returned to the runner. This dynamic rebound provides athletes with the responsiveness of a plated super shoe, without the additional weight and cost of a carbon plate.

Since Arnitel® Performance foams can be precisely tuned during the physical foaming process, it’s possible to achieve a spring-like effect that’s fast, stable and consistent across every footfall.

Design Outcomes

Arnitel® Performance enables designers to achieve high rebound without relying on ultra-thick midsoles or embedded plates. This unlocks design freedom – allowing shoes to remain low-profile and lightweight, with performance that endures.

Athlete Experience

“The rebound in this foam is wild. It just keeps giving – mile after mile, and with a pretty low stack height. I didn’t feel that late-race drag like I usually do in thinner shoes.”

— Trail runner testing norda™ 005 shoes

The Data Behind It

The dissipation angle, as depicted in the above graph as a function of frequency, is a measure of inner damping of the material. The higher the value, the more energy is lost during compression. Arnitel® Performance has much lower damping intrinsically, providing much better resiliency than TPU, both as a foam and as a molded raw material. This effect is more pronounced at higher frequencies. As a result, Arnitel® Performance foams demonstrate 15–20% higher rebound compared to TPU. Even after extensive compression cycles, rebound remains high – delivering lasting propulsion beyond 300+ miles on the trail.

Longer Lasting

Trail running puts relentless stress on every part of a shoe – especially the midsole. When foam breaks down early, runners lose cushioning, rebound and stability. For long-distance athletes, that drop-off in performance can happen just when they need support the most.

The Arnitel Advantage

Arnitel® is engineered to go the distance. Its unique TPC molecular structure offers exceptional fatigue resistance, maintaining rebound and structure even after hundreds of miles. While many super foams and carbon plated shoes start to collapse or lose spring around 100–150 miles, Arnitel® Performance midsoles, as used in the norda 005, keep performing well past 500 miles.

Its low compression set and high dynamic creep resistance help the foam maintain its original form under repeated loading – minimizing midsole breakdown and preserving the ride feel over time.

Design Outcomes

With Arnitel® Performance, designers no longer must choose between rebound and durability. They can deliver lightweight, high-performance shoes that keep their edge far beyond a single race or training season – extending product life and reinforcing brand trust.

Athlete Experience

“Most race shoes fall apart after 100 miles. I’ve got over 300 miles on these and they still feel solid. That’s a first for me.”

— Trail runner testing norda™ 005 shoes

The Data Behind It

Arnitel® Performance foams outperform TPU and EVA in long-term durability testing, retaining rebound and shape even after extended compression cycles. In dynamic fatigue tests, Arnitel maintains structure where TPU starts to take a permanent compression set, offering a more consistent experience over time and terrain.

Consistent Performance

Trail running throws everything at you – loose gravel, slick roots, hardpack, heat, cold, ice, snow and everything in between. Athletes need their shoes to perform on every surface, in every condition, every time – with fewer surprises underfoot, and more confidence to move fast when it matters.

The Arnitel Advantage

Arnitel® Performance delivers a rare combination: consistent rebound and comfort across both changing environments and long-term wear. While many midsole foams stiffen in the cold or soften under heat and fatigue, Arnitel® Performance remains remarkably stable – maintaining rebound, flexibility and cushioning from sub-zero temperatures up to 100°C, giving the athlete the same ride and feel under any climate condition.

Even after hundreds of miles, Arnitel® Performance foams continue to deliver a balanced ride. Where other materials break down or become uneven underfoot, Arnitel® Performance preserves its energy return and support – with every step.

Design Outcomes

With Arnitel® Performance, brands can promise athletes a predictable experience – on every trail, in every season, at every mile. The material holds up under pressure and time, helping runners stay focused on the course rather than their gear.

Athlete Experience

“These feel the same on day 20 as they did on day one. Whether it’s hot, cold, wet or dry – there’s no dead zone in the foam, and no surprises underfoot.”

— Trail runner testing norda™ 005 shoes

The Data Behind It

Arnitel® Performance maintains consistent rebound and modulus across the temperature range of -25°C to 50°C and approximately 60Mpa +/- 25%, where other materials typically show stiffness changes greater than ten times. It outperforms TPU and EVA in climate sensitivity tests, and demonstrates minimal change in energy over the lifespan of the foam to help preserve ride quality over extended use.

Sustainability

Athletes care about what’s underfoot – and what’s behind it. As the demand for performance grows, so does the pressure to reduce environmental impact. For too long, high-end running shoes have relied on hard-to-recycle foams that wear out fast and end up in landfills. The challenge is clear: do more, waste less.

The Arnitel® Performance Advantage

Arnitel® Performance is designed for a lower footprint. As a fully thermoplastic elastomer material , it’s inherently more sustainable than traditional EVA foams – which are thermosets with chemically crosslinked rubber, and are not easily recycled. Arnitel® Performance offers several grades with reduced carbon footprints, including bio-based versions made from 50% renewable resources, and bio-mass balanced options backed by ISCC certification.

Yet, it’s not just about the ingredients. Arnitel® Performance foams last longer, meaning fewer replacements and less material waste over time. And because it’s thermoplastic, it opens the door to true recyclability, supporting a more circular future for performance footwear.

Design Outcomes

With Arnitel® Performance, sustainability doesn’t have to come at the expense of performance. Designers can meet their carbon goals, support recycling initiatives and deliver gear that goes farther – without compromise.

Athlete Experience

“I love that this shoe isn’t just a race-day monster – it’s built to last, and it’s not headed for the trash after 100 miles. That matters to me.

— Trail runner testing norda™ 005 shoes

The Data Behind It

Arnitel® Performance ECO foams deliver up to 40% lower carbon footprint than fossil-based alternatives. And because Arnitel® Performance is a thermoplastic, it supports end-of-life recycling pathways that traditional EVA foams simply can’t match.

From elite-level energy return to multi-season durability, Arnitel® Performance is changing what footwear midsoles can do. It offers performance without compromise – on the trail, in the lab, and for the planet.

Further reading

Learn more about arnitel® performance

View related datasheet