May 4, 2025

Written byMohammad Yousaf

Running Shoe Foams : The Ultimate Guide [PDF]

Running shoe brands don’t always share enough details about their shoe foams. This make it hard for runners to find the right info. So, we’ve created an easy-to-follow guide to help you understand everything about running shoe midsoles.

Why is foam so important in running shoes?

The midsole is the heart of a running shoe. It helps you run farther and faster. It lowers your risk of injury. The foam in the midsole acts like a shock absorber. It soften the impact on your feet with every step. This reduces stress on your joints and muscles. This make runs more comfortable and less tiring. In short, it helps you keep up the pace, go the distance, and recover quicker.

Picking the right foam for your running shoes is key to improving performance and recovery. Whether you’re chasing a personal best in a race or looking for better injury protection and reduced fatigue, the right foam and stack height can make all the difference.

Running Shoe Foams

With so many running shoe brands and foams out there, it would take forever to cover them all. Especially it is difficult tot cover the discontinued or basic foams. They are mostly plain EVA and make up 99% of the market.

Still, we’ve worked hard to cover as many foams as possible in detail. We’ve dedicated full sections to most, while briefly mentioning others. Plus, we’ll keep this guide updated!

List of Premium Foams

List of Standard Foams Overview

Premium Foams

Back in 2017, Nike changed the game with ZoomX foam in their running shoes—even though top runners like Kipchoge had already used it in 2016. It was the first real “super foam,” giving back over 90% of energy in tests. But fun fact: Nike didn’t actually invent ZoomX. It’s made from a material called ZOTEK® PEBA, created by a UK company named Zotefoams.

What makes today’s high-performance foams so special is their unique chemical makeup. They’re built with lots of hydrogen bonds that help give more bounce and energy return. A 2018 study showed Adidas Boost foam gave back 75.9% energy, while Nike’s ZoomX hit 87% in their Vaporfly 3% prototype. Two more studies from 2023 and 2024 proved that PEBA foams perform better than older EVA foams—especially when used with carbon plates.

So, what makes premium foams stand out? The best midsoles using this stuff have 3 big perks:

• They give you crazy energy return – Usually between 80–95%.
• They save your legs – A long 20-mile run can feel more like an easy 10 or 15.
• They’re just super fun to run in – Bouncy, fast, and smooth!

But there are a couple of downsides:

• They don’t last as long as regular foams.
• They’re expensive – Even on sale, most cost over $100, and some can hit $200, $250, or even $300.

Alright, back to the good stuff. Like we said earlier, ZoomX changed everything. It gave Nike a huge head start about two years ahead of the competition in the crazy race to make the fastest running shoe. But now, other brands have finally caught up, and there’s a whole lineup of premium foams out there for you to try.

A lot of people think carbon-fiber plates are what make these shoes so fast. But actually, most of the magic comes from the foam itself. Studies from 2019 and 2021 showed that only shoes with true “super foams” could keep up with Nike’s Vaporfly. Others, like New Balance’s RC Elite v2 with FuelCell or Brooks’ Hyperion Elite 2 with DNA Flash, just didn’t perform as well.

So let’s dive into these foams starting with the one that kicked it all off.

Nike ZoomX (Pebax)

We’ve gotta give credit where it’s due Nike made the first true super foam. Period. And even today, ZoomX is still one of the best when it comes to energy return.

Before ZoomX, the top foam in the game was Adidas’ Boost, launched way back in 2013. It totally changed long-distance running and even helped set a few world records. Boost was probably the first foam to break the 75% energy return mark but these days, it’s starting to feel a bit outdated.

So, what is ZoomX made of? It’s a foam called Pebax. It is a special type of PEBA (short for Polyether Block Amide), invented by a French company called Arkema. It’s a fancy kind of plastic with both hard and soft parts, which makes it super flexible, strong, light and really, really bouncy!

ZoomX foam has gone through some big changes over the years. Here’s the lowdown:

ZoomX in the first Vaporflys. They were crazy soft and bouncy from 2017 to 2021, . It felt like you were running on clouds. But there was a catch: it didn’t last. After about 200-300 km, the foam would get creases and lose its pop, which was super frustrating given how pricey these shoes were. This version of ZoomX was also in the Alphafly Next%, Invincible Run, and Pegasus Turbo 2.

Then, in 2021, Nike released the Vaporfly Next% 2. People quickly noticed it felt firmer than the original, even though Nike claimed it was the same foam. The same thing happened with the Invincible Run 2 and Alphafly Next% 2 in 2022—they were firmer but way more durable, so you could get more miles out of them. The only shoe that didn’t follow this trend was the Streakfly, which stayed super soft despite coming out the same year.

Fast forward to 2023, and Nike dropped the Vaporfly 3 and Invincible 3. Some runners said they felt softer, but tests actually showed the Invincible 3’s ZoomX was 16% firmer than the last version. So yeah, ZoomX keeps evolving, and it’s not always what you’d expect!

Nike’s Next Nature lineup includes eco-friendly recycled ZoomX, like in the latest Pegasus Turbo. The catch? It’s heavier, firmer, and doesn’t give as much energy return as the regular ZoomX, so it doesn’t quite make the cut as a premium foam. That said, it’s still better than React foam and way ahead of standard EVA (ethylene-vinyl acetate) you’ll find in most shoes.

So, if you’re after top-tier energy return and a bouncy, ready-to-go feel right out of the box, ZoomX is a solid pick. Just remember, it might not last as long as some other midsoles, and shoes with ZoomX tend to come with a pretty steep price tag.

ASICS FF Turbo+ (PEBA)

In 2024, ASICS dropped the FF Turbo+, a major upgrade from the original FF Turbo. This new version is bouncier, softer, and even lighter than before. The secret? A tweaked supercritical manufacturing process that pumps more nitrogen into the foam, creating bigger bubbles and a smoother, more consistent texture.

This isn’t just a small upgrade—it’s a game-changer. The foam feels better underfoot and seriously boosts the performance of ASICS shoes that use it. We tested it out in the lab with the ASICS Superblast 2 and Metaspeed Sky Paris, and the difference was obvious. The shoes handled better, responded quicker, and just felt amazing to run in. It’s clear ASICS put in the work to make this foam stand out.

ASICS FF Turbo (Nylon)

FF Turbo, as it’s commonly called, was one of the first foams to really compete with Nike’s ZoomX. ASICS hasn’t spilled the beans on exactly what it’s made of, but we know it’s a nylon-based or PEBA midsole—kind of like a store-brand version of Pebax. It’s got similar energy return and bounce but feels firmer and more stable, so it’s worth keeping that in mind if you’re thinking about trying it out.

In our lab tests, we’ve found FF Turbo to be noticeably firmer than ZoomX. For example, the ASICS Metaspeed Sky+ measured 28.8 HA on our durometer, which is 34% firmer than the Nike Vaporfly Next% 2.

One quirky thing about this foam? It has a strong glue-like smell when it’s fresh out of the box—totally normal, though, so no need to worry. ASICS also claims FlyteFoam Blast Turbo is 45% lighter and 36% bouncier than your average EVA midsole, which is pretty impressive.

Adidas Lightstrike Pro (TPEE)

From 2017 to 2020, Adidas struggled to keep up in the super shoe race. They started with the Adizero Pro, a carbon-plated shoe combining Boost and Lightstrike foams, but it couldn’t compete with Nike’s Vaporfly. Then, they hit their stride with the original Adizero Adios Pro (internally called Majambo), featuring their new top-tier foam, Lightstrike Pro. Made by Shincell in China, this foam was a game-changer.

Lightstrike Pro is different it’s made from TPEE (Thermoplastic Polyester Elastomer), not PEBA like most premium foams. This gives it some unique traits:

• Crazy durability: While other foams wear out fast, Lightstrike Pro stays strong even after 200-300 km. Some runners have logged over 1,000 km on these shoes!
• Break-in required: It needs 2-3 runs to hit its stride, and it performs best between 50 km and 250 km. After that, it’s still good but not quite as bouncy.
• Firm but adaptable: It’s firmer than most super foams, but it softens up in warmer weather.

Lightstrike Pro might have slightly less energy return than ZoomX, but the difference is tiny. Just look at the records and wins it’s helped achieve like Adidas’ podium sweep at the 2023 Boston Marathon. Our tests back this up too.

In 2023, Adidas dropped the Adizero Adios Pro Evo 1, a limited-edition shoe mostly for elites. Only 521 pairs were released to the public to meet World Athletics rules. This shoe introduced Lightstrike Pro Evo, a lighter, less dense version of the foam. Made with a groundbreaking non-compression molding technique and supercritical process, it’s cut into shape using CNC machines a first in the industry. This method shaves off 50g compared to the Adios Pro 3 and boosts energy return, but it also comes with a sky-high price tag.

Fast forward to 2024, and Adidas tweaked Lightstrike Pro again for the Adios Pro 4. They kept TPEE as the base but made the foam airier and much softer. The trade-off? Durability takes a hit, but the plush, soft feel is a big win. Like most things in life and running shoes it’s all about balance.

Saucony PWRRUN PB (Pebax)

The American brand also partners with Arkema to use Pebax, but they’ve gone a different route than Nike’s ZoomX. Their foam, PWRRUN PB, is made from small pellets similar to how Boost is designed instead of being one solid piece.

PWRRUN PB is a great all-around foam: it’s soft but still responsive, lasts a long time, and gives solid energy return. Saucony has had a lot of success with it, especially in their Endorphin line of shoes.

The pellet design includes grooves and flex points that help the foam move with your foot, giving you a more personalized fit and better comfort.

Oh, and here’s a cool tidbit: PWRRUN stands for “Performance Welded, Responsive, Resilient, UNderfoot foam,” and the PB comes from Pebax. So, it’s not just a catchy name it’s packed with tech!

Saucony PWRRUN HG (Pebax)

This is Saucony’s newest top-tier foam and honestly one of the snappiest options available right now. Currently, you’ll only find it in three shoes: the Endorphin Elite, Endorphin Pro 4, and the Terminal VT track spike.

Now, the HG version of PWRRUN? That’s a different beast – noticeably firmer and more stable. Think of it like Lightstrike Pro compared to ZoomX – same ballpark of performance, but with a distinctly different feel underfoot.

While Saucony hasn’t officially revealed how they make PWRRUN HG, our testing suggests it’s a supercritical Pebax foam with a structure similar to ZoomX. So you can expect comparable energy return and responsiveness, just with that firmer, more stable character Saucony’s known for.

Saucony IncrediRUN (TPEE)

Back in March 2024, Saucony dropped a trademark filing for “IncrediRUN” that had us in the lab buzzing with theories. What were they cooking up? The mystery deepened when they released a super-exclusive Olympic edition of the Endorphin Elite 2 for Paris 2024 – featuring this crazy-soft foam they claimed was the most resilient ever put in a running shoe. Talk about confidence!

Turns out that mystery foam was IncrediRUN all along (now the trademark makes perfect sense). The official announcement came late 2024, with the full consumer launch planned for Spring 2025. We’ll first see it in the Endorphin Elite 2, followed by shoes like the Endorphin Trainer that’ll use it in key areas.

With hype like this, you bet we’re itching to get our hands on it and put those bold claims to the test. Can it really live up to the name?

Puma Nitro Elite (PEBA + EVA / A-TPU)

Puma’s top racing foam is a bit of an oddball in the super foam world. While they’ve kept the exact recipe under wraps, we do know it’s a nitrogen-infused blend of PEBA and EVA.

By mixing these materials, Puma aimed for that sweet spot between performance, durability, and affordability. The trade-off? It doesn’t quite match the energy return of the very best foams out there. But that extra durability makes it a hit with runners who want a shoe that can handle serious training miles without falling apart.

Pair that with Puma’s legendary PumaGrip outsole, and you’ve got shoes that are fantastic trainers – just don’t expect to see many podium finishes in them at major marathons.

Things got interesting in late 2023 when Puma dropped the Fast-R Nitro Elite 2 with their new A-TPU (Aliphatic TPU) foam. The company claims this stuff delivers a whopping 93% energy return, and from our test runs, we can confirm it’s definitely bouncier than before.

Could A-TPU be the next big thing in super foams? It’s early days, but this material looks promising as a PEBA alternative that might actually hold up better over time. It maintains its pop through a full marathon and resists UV degradation better than most foams.

Here’s the funny thing: While the numbers show A-TPU matches or even beats PEBA in energy return (that 93% figure is legit), it doesn’t have that same magical, effortless feel underfoot. You might finish a run thinking “Hmm, that didn’t feel as fast as my Vaporflys…” only to check your splits and realize – surprise! – you were flying.

Hoka Unnamed (PEBA)

After years of “when will Hoka drop a real supershoe?!” whispers among runners, they finally delivered in 2023 with the Rocket X 2 – complete with their first proper PEBA foam.

Funny thing? Hoka’s playing it mysterious with this foam. Three years later, it still doesn’t have an official name (come on, Hoka, help us out here!). Even after poking them for details, they’re keeping quiet. What we do know: it’s a dual-density PEBA foam with killer bounce – not as pillowy as ZoomX but softer than FF Turbo. That Goldilocks “just right” feel.

We’re betting Hoka will spill the beans soon (and finally give this foam a proper name), plus roll out more racing and training shoes with it. Heck, they’ve already started – the Mach X trainer sneakily uses this same PEBA magic.

Decathlon VFOAM (Pebax) / VFOAM PLUS (Pebax + EVA)

When Decathlon decided to jump into the supershoe game with their 2022 Kiprun KD900X, teaming up with fellow French company Arkema was a no-brainer. The result? Their VFOAM technology – a Pebax-based midsole that, like Saucony’s PWRRUN PB, uses a pellet construction.

While VFOAM delivers solid bounce and keeps things light, it doesn’t quite match the energy return of top-tier foams. But here’s the kicker: Decathlon gives you the most affordable ticket into the premium foam club – at least if we’re talking sticker price before those flashy brand discounts.

Fast forward to 2024, and Decathlon leveled up with the KD900X LD featuring VFOAM PLUS. This new version feels noticeably softer underfoot, blending Pebax with EVA and ditching the pellet design. On paper, mixing in EVA might seem like a step backward, but we’re guessing Decathlon’s betting on better durability – a smart play for runners who want performance that lasts.

Mizuno Enerzy Lite+ (PEBA)

Mizuno’s always been late to the supershoe party, and here’s why – until recently, they didn’t have a foam that could hang with the big players. But that all changed with Enerzy Lite+.

This PEBA-based foam feels like running on clouds – seriously, it’s got that same dreamy softness as early ZoomX. There’s just one catch: it’s about as stable as a Jenga tower. That’s why Mizuno got clever with the Wave Rebellion Pro 2, mixing this bouncy-but-wobbly foam with firmer Enerzy Lite sections to keep you from face-planting.

The result? A shoe that somehow balances that insane cushion with actual runnability. Mizuno might have been late, but they’re making up for lost time in style.

Mizuno Enerzy NXT

When Mizuno dropped their new EVA foam in 2024, we rolled our eyes. Another EVA? Really? Even with Mizuno hyping it as “Pebax-level,” we weren’t buying it.

Then we laced up the Wave Sky 8.

Turns out, this isn’t just another brick-like EVA. Mizuno’s tweaked it into something stupidly soft and way bouncier than it has any right to be. It’s like they took regular EVA, put it through a supercritical glow-up, and turned it into foam that actually feels premium.

We’ll admit it: Mizuno proved us wrong. They took a boring old material and made it legit fun to run in. Still not quite ZoomX or FF Turbo territory, but for EVA? Damn impressive.

Reebok Floatride (Pebax)

Let’s be real—when was the last time you saw someone actually running in Reeboks? I scan shoes on every run, and I can’t even remember spotting a pair. But here’s the kicker: Reebok might be one of the sneakiest affordable ways to get Pebax under your feet.

Just don’t get tripped up by their naming game:

• Floatride = The real deal Pebax foam (premium bounce, ultralight)
• Floatride Energy = Budget TPU foam (Boost-like, not bad but not Pebax)

And that Pebax magic? Reebok says it’s 50% lighter than their old EVA with way better energy return. So yeah, the tech’s legit—if only more runners gave it a shot.

Li-Ning BOOM (Pebax)

While Chinese brands are popping up more in elite races, Li-Ning might have the best hidden gem: their BOOM foam (yes, that’s the actual name—peak Chinese branding).

This stuff is no joke—a Pebax-based, supercritical midsole that feels eerily close to ZoomX. Proof? The 2023 Seville Marathon winner (2:04:59) and 3rd place both smoked the competition in Li-Ning’s Feidian shoes.

But here’s the catch: unless you’re in China, good luck getting a pair. Sure, you could import them, but after customs and shipping, you’re paying way too much for shoes you could’ve bought locally in the time it takes to brew coffee.

On Helion HF

On showed up late to the superfoam party—then dropped Helion HF like a mic. With stars like Hellen Obiri and Mario García Romo repping the Swiss brand, this Arkema Pebax-based foam had big shoes to fill.

And damn, does it deliver.

The Good:

• Ultra-reactive pop (perfect for chasing PBs)
• Lighter than your excuses for skipping tempo day

The Catch:
Durability’s… enthusiastic. On literally prints in the shoebox: “Lifespan = 4 marathons (+ infinite memories)”. Translation: enjoy the ride while it lasts.

Right now, only elite models like the Cloudboom Echo 3 and Cloudmonster Hyper get this foam. But with hype like this? More are coming—bet on it.

Topo Pebax Powered (Pebax)

Topo might not be a mainstream name in running shoes, but they’ve cracked the code on delivering premium Pebax foam at an accessible price point, as demonstrated by their Cyclone 2 model. For runners who want high-performance cushioning without the typical super shoe price tag – especially those needing a roomier toe box – Topo presents a compelling option. Their Pebax Powered foam uses a pellet-based construction similar to Saucony’s PWRRUN PB, offering a smart balance of durability, energy return, and affordability.

While it doesn’t quite match the ultra-bouncy feel of top-shelf foams like ZoomX or FF Turbo+, it delivers impressive performance for the price. Just be aware you’re getting a slightly firmer ride compared to those premium options. What makes Topo truly stand out is their ability to package this Pebax technology in shoes that accommodate wider feet – a rare combination in today’s market.

Brooks DNA Gold (PEBA)

Brooks’ long-awaited leap into the superfoam game has left many runners scratching their heads. While Nike was revolutionizing the market with ZoomX back in 2017, and competitors like Adidas and ASICS were quick to follow with their own premium foams, Brooks stubbornly stuck with their DNA Flash v2 compound for years – a puzzling choice when even Chinese brands like Anta and Li-Ning were developing competitive superfoams.

Finally, in 2024, Brooks unveiled the Hyperion Elite 4 PB, their first proper PEBA-based racing shoe complete with a Speedvault+ plate. The fact that pros like CJ Albertson and Des Linden have been spotted racing in these, while Josh Kerr is already testing a Hyperion Elite 5 prototype, confirms Brooks is serious about catching up. Better late than never, but one has to wonder: what took them so long? The running world moved on from basic EVA blends years ago, making Brooks’ delayed entry into the PEBA game all the more baffling. At least now runners have another viable option in the super shoe market – even if it arrived fashionably late to the party.

Which is the best premium foam that you must choose?

Standard Foams

Let’s be honest—standard foams won’t make you feel like you’re bouncing on clouds, but they’ve got serious merits. Think of them as the reliable sedans of running shoes: not flashy, but they’ll get you where you need to go without draining your wallet.

Why They Shine:

• Budget-friendly: Shoes often priced under $100 because these foams cost peanuts to make.
• Built to last: Many hit 1,000+ km while premium foams are already retiring.
• Stability champs: Great for runners who need extra support underfoot.

The Trade-offs:

• Energy return? Meh: You’re getting 60–80%, not the 85%+ of premium foams.
• Winter bricks: Freeze a React foam shoe and it stiffens like concrete (we tested it—62.5% firmer!). ZoomX? Just 10.3%.
• Long-run fatigue: High-mileage runners might miss that leg-saving bounce.

Bottom line? Standard foams won’t win races, but they’ll survive your daily grind—rain, cold, or 500 km later.

Skechers HyperBurst (EVA) / HyperBurst Pro (TPU)

Skechers quietly pulled off something impressive with their HyperBurst foam. By pumping supercritical CO₂ into EVA, they created a lighter, bouncier version of a material everyone else had written off. The result? A foam that actually made people take Skechers running shoes seriously.

Their CO₂ method was so effective that brands like New Balance and Brooks copied the approach—just swapping in nitrogen to avoid Skechers’ patents. Talk about flattery!

But EVA has limits, so Skechers leveled up with HyperBurst Pro, switching to TPU (like Adidas’ Boost) for better energy return. It’s an upgrade, but still not quite premium foam territory. Here’s the lineup:

• HyperBurst: The OG supercritical EVA—light, soft, durable
• HyperBurst ICE: Refined EVA formula (think v2.0)
• HyperBurst Pro: TPU version—firmer, springier, but heavier
• 2025’s HyperBurst Pro: New TPEE+EVA blend (durability focus)

The verdict? Fantastic daily trainers with a fun ride, but not your go-to race shoes. That said, if Skechers drops a PEBA version soon? Game on.

New Balance FuelCell [Until 2024] (TPU / EVA)

When New Balance launched FuelCell in 2019, they created one of running’s most unpredictable foams. This nitrogen-infused EVA/TPU blend (think Skechers HyperBurst Pro’s cousin) delivers decent 70-80% energy return – not quite elite, but solid for daily training.

Here’s where it gets interesting: FuelCell feels dramatically different in every shoe. Case in point? The Rebel v3 tested 31.6% softer than the Rebel v2 in our lab. New Balance admits they tweak the formula constantly – great for variety, frustrating if you crave consistency.

The real buzzkill? Older FuelCell (pre-2024) turns into a brick in cold weather:

• SuperComp Trainer: 57.4% firmer when chilled
• Rebel v2: A brutal 115.4% stiffness spike – basically running on plywood

While not quite matching premium foams, FuelCell’s versatility makes it a wildcard in New Balance’s lineup. Just maybe skip winter runs with the older models.

Nike React / ReactX (TPE + EVA)

Back in 2017, while everyone was drooling over ZoomX, Nike quietly dropped React foam—first in basketball shoes, then in the hit Epic React Flyknit runner. Today, it’s everywhere from Pegasus trainers to trail shoes, and for good reason.

What Makes React Special?

• A clever EVA/TPE blend that’s soft, durable, and dirt-cheap to produce (no wonder Nike loves it)
• The perfect workhorse foam for daily miles—just don’t expect race-day bounce
• Nike’s answer to Adidas Boost after their Lunarlon foam fell behind

The Backstory:
While ZoomX was the star, its sky-high costs made it a niche product. React became the practical solution—not revolutionary, but a huge upgrade over aging Lunarlon.

Enter ReactX (2023):
Nike’s eco-friendly upgrade boasts:
✓ 13% more energy return
✓ 43% lower carbon footprint
We put it to the test in the InfinityRN 4, and it delivers on both comfort and sustainability.

React may never steal headlines like ZoomX, but it’s the reliable backbone of Nike’s lineup—proof that sometimes, the best innovations are the ones you don’t notice.

Nike Cushlon / Phylon (EVA)

These days, when Nike needs reliable cushioning for their running shoes, they increasingly turn to Cushlon 3.0 – their top-tier EVA-based foam that’s leaving older options like SR-02, Phylon and the nearly forgotten Lunarlon in the dust.

So what makes Cushlon special? Think of it as Phylon’s smarter, more sophisticated cousin. By blending Phylon with rubber in specific proportions, Nike created a foam that keeps all of Phylon’s good qualities while delivering noticeably better cushioning. Our testing confirms Cushlon 3.0 strikes that sweet spot – comfortable enough for long runs yet durable enough to last. That’s why you’ll find it in workhorse trainers like the Vomero 17.

Here’s why we think Cushlon isn’t going anywhere:
✓ Crazy affordable to manufacture
✓ Consistently lasts hundreds of miles
✓ Runners aren’t complaining (and that’s saying something)

Meanwhile, Phylon remains Nike’s old reliable – that compressed pellet EVA foam you’ll find throughout their lineup. The process is straightforward: take EVA pellets, heat them up, compress them in a mold, and voila – you’ve got Phylon. It may not be fancy, but it gets the job done.

While ZoomX and React get all the attention, Cushlon 3.0 quietly does the heavy lifting in Nike’s daily trainers. And with version 4.0 likely in development, this underrated foam’s story is far from over.

Nike ComfiRide (EVA)

Nike’s latest foam addition, ComfiRide, is making waves where it counts most – the under $100 price range. This no-frills EVA foam serves as Nike’s answer for runners who want dependable cushioning without breaking the bank.

What We Know So Far:

• Softness Level: Middle-of-the-road – not pillowy but not firm either
• Durability: Shows promise for lasting through serious mileage
• Energy Return: Don’t expect miracles (it’s no ZoomX) but gets the job done
• Current Models: Only in select budget shoes for now

Our early take? ComfiRide seems like a smart compromise – sacrificing some bounce to hit that sweet $100 price point while avoiding the pitfalls of truly cheap foams. It’s essentially Nike saying: “Here’s reliable cushioning at half the price of ReactX.”

While it won’t wow performance-focused runners, ComfiRide could become the dark horse of Nike’s lineup – especially if they refine it further. We’ll be keeping close tabs as more models hit the market to see if this budget foam can punch above its weight class.

The bottom line: For casual runners or those watching their wallet, ComfiRide looks set to deliver exactly what most need – dependable comfort at an accessible price.

Adidas Boost (TPU)

It’s easy to forget now, but Boost wasn’t just an upgrade—it was a revelation. Before super foams like ZoomX, before PEBA took over, there was Boost: the first midsole that made EVA feel ancient overnight.

Why Boost Was a Big Freaking Deal

• It smashed records: Dennis Kimetto’s insane 2:02:57 Berlin Marathon (2014) in the Adios Boost 2? Joyciline Jepkosgei’s 1:04:51 half-marathon (2017)? All thanks to that TPU bounce.
• It wasn’t even Adidas’ idea: German chemical giant BASF invented it as Infinergy—Adidas just had the vision to turn it into a running shoe midsole.
• In 2013, it was ZoomX-level revolutionary: Nothing matched its combo of softness, bounce, and durability.

The Downfall of a Legend

Boost’s fatal flaw? Weight. By today’s standards, it’s a tank—great for comfort, bad for speed. That’s why Adidas has quietly been phasing it out of performance running shoes (though it still pops up in casual sneakers).

What’s Left of Boost?

Adidas isn’t done with TPU yet. Their new Light Boost is a trimmed-down version—less dense, lighter, but still not competitive with today’s PEBA foams.

The Legacy

Boost paved the way for modern super foams. Without it, we might not have ZoomX, Lightstrike Pro, or any of the bouncy midsoles we take for granted today. Not bad for a foam that started as a chemistry experiment.

Adidas Light Boost (TPU)

When Adidas finally launched Light Boost in 2023, our immediate reaction was “Better late than never!” The original Boost foam had one glaring weakness – its weight – and Adidas has now addressed this with a new version that’s 30% lighter. Our lab tests with the Ultraboost Light and Ultraboost 5 confirmed the significant weight reduction. While this innovation arrived three to four years later than it ideally should have, it delivers exactly what runners wanted: all the durability and reliability of classic Boost, but in a much lighter package.

Light Boost maintains that signature bounce and comfort Boost is known for, just without the heavy, bulky feel that made the original outdated for performance running. It’s not quite a superfoam that will compete with today’s PEBA-based options, but for everyday runners who loved Boost’s characteristics, this is the meaningful upgrade they’ve been waiting for. The timing may not have been perfect, but Light Boost proves good things come to those who wait – even if they have to wait a little too long.

Adidas Lightstrike (TPU) / Lightstrike EVA (EVA) / Lightstrike 2.0 (EVA)

Adidas’ Lightstrike foam saga reads like a case of corporate indecision. When it first appeared in the ill-fated Adizero Pro, Adidas marketed it as a TPU compound, boasting about its lightweight energy return. Yet just months later, the same “Lightstrike” name was slapped on an EVA foam in the Adizero SL’s press release—no explanation given. This bait-and-switch left runners scratching their heads. The plot thickened in 2023 with Lightstrike 2.0, a marginally softer EVA iteration in shoes like the Boston 12, further cementing the material’s identity crisis.

While some speculate early versions blended TPU with EVA before Adidas abandoned the formula, the more likely (and amusing) scenario is that the Germans simply changed their minds midstream. Regardless of its murky origins, one thing’s clear: every Lightstrike iteration delivers a firm, stability-focused ride that feels outdated in today’s bouncy foam landscape. It’s a curious stumble for the brand that once revolutionized midsoles with Boost—proof that even giants miss the mark sometimes.

Adidas Dreamstrike+ (PEBA)

Adidas’ Dreamstrike+ might carry that coveted PEBA label, but don’t mistake it for an elite foam—at least not by our standards. When it debuted in the Supernova Rise, the hype was real: Finally, an affordable PEBA option for daily training! But after testing, we found it behaves more like a premium TPU or supercritical EVA, falling short of the explosive bounce you’d expect from Lightstrike Pro or ZoomX.

That said, let’s give credit where it’s due: Dreamstrike+ is undeniably a step forward for Adidas. It’s comfortable, reasonably energetic, and built to last—plus, with 20% bio-based materials and a fresh feel that’s worlds apart from Boost, it shows Adidas is (slowly) moving beyond its TPU roots. It may not rewrite the foam hierarchy, but as a first attempt at accessible PEBA, it’s a solid foundation to build on.

ASICS FF Blast / FF Blast+ (EVA + OBC)

Long before Nike shook up the running world, ASICS was quietly giving Adidas’ Boost a run for its money back in 2014. The Japanese brand pulled off something remarkable – they transformed boring old EVA into a foam so advanced that most runners wouldn’t even recognize it as EVA in a blind test. Their secret? Blending EVA with OBC (Olefin Block Copolymers), a super-elastic thermoplastic that turbocharges the foam’s bounce.

But ASICS didn’t stop there – they licensed this patented tech from Dow Chemical, then took it further by mixing in Kevlar fibers (yes, the same stuff used in bulletproof vests) to create FlyteFoam Blast. The result? A foam that’s shockingly light (up to 55% lighter than standard EVA), incredibly springy, and durable enough to power tall-but-light shoes like the Novablast 4. While it might not get the hype of today’s PEBA foams, this clever engineering proves ASICS was years ahead in the foam game – and still delivers one of the most fun rides in running shoes today.

ASICS FF Blast MAX (POE)

ASICS is stepping up its foam game with the introduction of FF Blast MAX, the latest evolution in their midsole technology. We’ve had our hands (and feet) on the Novablast 5 featuring this new foam, and while it looks similar to FF Blast+ and FF Blast+ ECO under magnification, the real-world feel tells a different story. ASICS promises an 8.5% boost in energy return, and our testing confirms this isn’t just marketing fluff – there’s a noticeable improvement in both softness and responsiveness. The secret lies in the switch from their traditional EVA+Olefin blend to POE (Polyolefin), a material that brings several advantages to the table. POE offers better compression resistance, maintains its properties in cold weather, and delivers more bounce than standard EVA.

This isn’t just an incremental upgrade – it’s a meaningful step forward that could influence the entire industry, as we’ll likely see other brands exploring POE formulations in coming years. While FF Blast MAX is just beginning its journey, history suggests ASICS will likely refresh their foam technology again in 2-3 years, following the same pattern as FlyteFoam, FF Blast, and FF Blast+ before it. For now though, runners get to enjoy a foam that strikes an impressive balance between comfort, energy return, and durability – proving ASICS remains a serious player in the ongoing foam wars.

ASICS FlyteFoam (EVA)

ASICS’ FlyteFoam (and its Lyte/Propel variants) takes ordinary EVA and gives it a high-tech makeover by blending in ecological polyethylene. The result? A featherlight foam that’s tougher than standard EVA—basically, EVA 2.0. It’s so light it makes even FF Blast feel heavy, but there’s a catch: that weight savings comes at the cost of bounce.

That’s why you’ll find it in entry-level shoes and ultra-light racers like the Noosa Tri 14, where every gram matters. ASICS tweaks the formula for each shoe—softer for cushion-focused models, firmer for stability shoes—proving even “basic” foams can be versatile when engineered right. It’s not the bounciest option, but for runners prioritizing lightness and durability, FlyteFoam gets the job done.

Brooks DNA Tuned (EVA)

Brooks just threw its hat into the foam innovation ring with DNA Tuned, a nitrogen-infused EVA midsole featured in their new Glycerin Max. After putting it through lab tests, here’s the scoop: Brooks took a page from ASICS and Nike’s playbook by blending two foams—but with a slick twist. Instead of glueing layers together, they fused them into a single slab, boosting durability while cutting manufacturing waste. The result? A yellow section that’s firm and snappy (perfect for propulsion) and a white, airier foam that’s all about plush heel cushioning—visible even under our microscope.

Now, let’s be real: Brooks’ claim that this “redefines cushioning” is pure hype. It’s a clever engineering feat, sure, but it’s no Pebax-level revolution. For daily trainers? Great step forward. For shaking up the foam wars? Not quite. Still, props to Brooks for trying something new—glue-free midsoles could be the next eco-friendly trend.

Brooks DNA Loft (EVA) / DNA Flash (EVA) / DNA Amp (TPU)

Brooks finds itself in an interesting position – much like Skechers, this American staple hasn’t yet cracked the code on premium foams or true racing shoes. That said, their lineup of standard foams is surprisingly versatile, offering three distinct options we’ve ranked by bounce:

At the foundation is DNA Loft, their workhorse EVA blend enhanced with rubber for extra durability. It’s the reliable choice you’ll find in staples like the Ghost and Glycerin series – not flashy, but gets the job done. The newer nitrogen-infused DNA Loft v3 kicks things up a notch with lighter weight and better responsiveness.

Stepping up the energy return is DNA Flash, Brooks’ answer to the nitrogen foam trend (using N₂ instead of Skechers’ CO₂ method to avoid licensing fees). While the 2024 v2 version shows improvement, it still falls short of being a true performance foam, better suited to tempo shoes like the Hyperion line than elite racing.

Topping their bounce chart is DNA Amp, their TPU-based alternative similar to Adidas’ Boost. Since its 2018 debut, it’s delivered the brand’s best energy return, though the weight penalty means it’s confined to trainers like the Levitate rather than racers.

Here’s the bottom line: With a strong stable of American elite athletes, Brooks is overdue for a foam breakthrough. While their current options serve everyday runners well, developing a true premium foam isn’t just nice-to-have – it’s essential if they want to compete at the highest levels. The good news? If brands like Skechers can make the leap, Brooks certainly can too. That next-gen foam can’t come soon enough for their podium-chasing athletes.

Brooks BioMoGo DNA

While Brooks hasn’t cracked the premium foam game yet, they deserve serious props for their BioMoGo DNA – a sneaky-good EVA blend that combines their BioMoGo and DNA tech into one impressive package. Here’s why it stands out:

First, it laughs in the face of cold weather. While most EVA turns into sidewalk concrete when temperatures drop, BioMoGo DNA stays just as soft and flexible – our lab tests with the Trace 2 (a steal at $100) proved it outperforms foams twice its price in winter conditions.

Then there’s the eco-angle: that “Bio” prefix isn’t just marketing. This midsole breaks down 20x faster than standard foam in landfills, making it one of the few running shoes you can feel slightly better about retiring.

Is it ZoomX? Obviously not. But for an affordable, all-weather, planet-friendlier foam? Brooks nailed it. Now if only they’d apply this innovation to a racing shoe…

New Balance Fresh Foam / Fresh Foam X (EVA / EVA + PEBA)

When New Balance launched Fresh Foam in 2013, it was their high-tech counterpunch to Adidas’ Boost – a data-designed EVA foam with computer-mapped cushioning. Using fancy algorithms, they sculpted the midsole’s geometry to deliver targeted softness and support, creating that signature plush-but-stable ride.

Fast forward to today, and New Balance is quietly upgrading the formula. In models like the Fresh Foam X Balos (with its wild rocker design), they’ve started blending 20% PEBA with 80% EVA – a smart tweak that boosts bounce without ditching Fresh Foam’s reliable feel. It’s not full-on superfoam territory, but for daily trainers? This evolution proves EVA still has tricks up its sleeve.

Saucony PWRRUN (EVA + TPU) / PWRRUN+ (TPU)

Saucony’s foam evolution tells an interesting story. In 2015, they debuted EVERUN – decently durable but lacking in bounce and lightness. By 2019, they’d upped their game with two smarter options:

PWRRUN (EVA+TPU): This stuff is ridiculously soft – our lab measured it at just 20.0 HA in the Guide 16 (that’s 20% softer than your average trainer). Perfect when you want that pillow-like feel underfoot.

PWRRUN+ (TPU): Here, Saucony ditched EVA entirely for expanded TPU. Yes, it’s heavier (hello, Triumph line), but the trade-off is worth it: better energy return and cold-weather performance that puts EVA to shame. Our freezer test proved it – while the TPU-based Triumph 19 barely stiffened (+3.6%), the EVA Kinvara 13 turned nearly 28% firmer in the cold.

What’s impressive? Saucony’s obsession with lightness means even their TPU foam weighs less than Adidas’ Boost (though you sacrifice some durability). For a brand that started with mediocre EVERUN, they’ve come a long way in the foam arms race.

Hoka ProFly / ProFly+ (EVA)

Hoka’s foam story is a fascinating one. The brand that basically invented maximalist shoes a decade ago somehow found itself playing catch-up in the superfoam race. While their standard foams were (and still are) some of the best in the business, the lack of a premium option meant their racers like the Carbon X 3 couldn’t compete – and even cost them top athletes like Scott Fauble. Thankfully, that’s changing with their new PEBA foam we covered earlier.

But let’s talk training shoes – where Hoka’s standard foams really shine:

ProFly (EVA): Hoka’s bread and butter. This isn’t your average EVA – they’ve engineered it to be softer in the heel while keeping the forefoot snappy. The result? A surprisingly lively ride for daily training, though don’t expect ZoomX-level energy return.

ProFly+ (Supercritical EVA): The Mach 5’s secret sauce. While Hoka’s been quiet on specs, our lab tests don’t lie – it’s a big step up. The Mach 5 with ProFly+ measures a whopping 28.5% softer than the ProFly-based Mach 4, with noticeably better bounce. That supercritical process makes all the difference.

What’s impressive is how Hoka continues to squeeze every last drop of performance from EVA. While other brands chase fancy materials, Hoka proves that smart engineering can make even “basic” foams perform exceptionally well for daily training.

On Helion (EVA + OBC)

Taking a page from ASICS’ playbook, On gave their EVA foam an upgrade by blending it with OBC – the same springy thermoplastic that makes FlyteFoam Blast so responsive. The result? More bounce than regular EVA and better performance when temperatures drop. But let’s be real – what really makes On shoes stand out is that wild CloudTec system. Those signature hollow pods aren’t just for show – they compress on impact to absorb shock, then lock together to give you a solid push-off. It’s like having tiny trampolines under your feet!

We’ve noticed some runners complain about On’s foams feeling too firm – and our lab tests back this up. The Cloudmonster (25.8 HA) and Cloudnova (29.0 HA) both measured firmer than the average shoe (25.0 HA). The good news? Recent models like the Cloudsurfer show On’s clearly listening, delivering a plusher ride while keeping that unique CloudTec responsiveness.

What’s cool is how On keeps evolving – tweaking their foam blends and pod designs to find that perfect balance between their signature responsive feel and the cushioning runners want. They’re proving that sometimes, how you design the foam can be just as important as what’s in it.

Altra Ego (EVA) / Ego Pro (TPE) / Ego Max (EVA + TPU)

Altra, a brand known for its commitment to a 0-mm heel-to-toe drop and natural-shaped toe boxes, offers more versatility when it comes to midsoles. Runners can choose from 3 distinct options:

• Altra Ego (EVA): While this is their most affordable and entry-level midsole, it’s not a bad foam by any means. In fact, the Altra Ego provides one of the most enjoyable rides you’ll experience with an EVA foam, as it’s both soft and highly responsive. Our lab-testing of the Rivera 2 revealed that it was 40% softer than the average shoe!
• Altra Ego Pro (TPE): As the fastest of the three options and designed for racing shoes like the Vanish Carbon, Altra couldn’t settle for a basic TPE foam. Instead, they infused it with a supercritical gas à la FuelCell to make it lighter and bouncier. Despite these enhancements, it still falls short of joining the ranks of premium foams.
• Altra Ego Max (EVA + TPU): The third foam was created to bridge the gap between the less energetic Ego and the faster Ego Pro. Ego Max combines EVA and TPU to improve durability and energy return, though it does add some weight to the shoe and it’s on the firmer side. That’s why they use it in the super-high-stack VIA Olympus.

Puma Nitro (TPEE / PEBA)

Puma’s Nitro foam plays a clever chemical trick – it takes TPEE (already a springy material) and pumps it full of nitrogen gas to create something even softer and bouncier. Despite what the name might suggest, there’s no EVA here – this is pure performance chemistry.

What makes Nitro special is how it straddles the line between affordability and performance. While it won’t last as long as some tank-like trainers, it delivers a seriously fun ride at a reasonable price point. The magic really happens when Puma blends it with their premium Nitro Elite foam, like in the fan-favorite Deviate Nitro 2 – you get 90% of the performance at half the cost.

But here’s the exciting part: Starting in 2024, Puma’s taking Nitro to the next level by swapping TPEE for PEBA. This means we’re about to see Nitro transform from a “pretty good” foam to potentially a “wow” foam. If they maintain that nitrogen infusion while upgrading to PEBA? Game on.

PUMA Profoam / Profoam Lite (EVA)

PUMA’s Profoam lineup offers a cost-effective alternative to their premium Nitro foam, serving two key purposes in their shoe ecosystem. The standard Profoam and lighter Profoam Lite versions deliver durable, stable platforms for both budget-conscious runners and those needing extra support. While firmer than bouncy Nitro, these EVA-based foams provide reliable cushioning that holds up mile after mile.

The clever Velocity Nitro 2 demonstrates PUMA’s smart foam strategy perfectly. By pairing responsive Nitro with supportive Profoam Lite in a dual-density midsole, they create a versatile trainer that balances energy return with everyday durability. This combo gives runners Nitro’s pep where they need it most (underfoot) while maintaining Profoam’s structural integrity in key support areas.

What makes Profoam stand out is its purposeful design:

• Budget-friendly performance for daily trainers
• Enhanced stability from its firmer composition
• Proven durability that outlasts many premium foams
• Strategic pairing with Nitro in performance models

While it may not have Nitro’s flashy bounce, Profoam proves that sometimes reliability trumps revolution – especially when you’re logging serious training miles.

Under Armour FLOW

FLOW made its debut in Steph Curry’s signature basketball shoes, where it promised a two-in-one solution: cushioning and traction in a single slab of foam. By blending standard EVA with a rubberized layer, it ditched the traditional outsole—great for simplifying production, less great for high-performance running.

In running shoes like the SlipSpeed Mega, FLOW falls short of being a standout midsole. Its energy return is mediocre at best, placing it firmly in the “just okay” category. While it’s a cheap, convenient option for casual runners or lifestyle wear, don’t expect the responsiveness or durability of premium foams.

The Bottom Line?
FLOW works as a budget-friendly, all-in-one system—perfect for slip-on convenience or light training. But if you’re chasing PBs or logging serious miles, this isn’t the foam for you.

Under Armour HOVR (EVA + OBC)

Under Armour’s running division has always played second fiddle to their other sports categories – and it shows in their foam technology. While brands like ASICS and Nike push boundaries with premium compounds, UA’s HOVR foam (developed with Dow Chemical in 2018) remains stuck in the past, delivering one of the firmest rides we’ve tested. The HOVR Sonic 6 isn’t just stiff – it’s among the most rigid shoes we’ve ever measured in our lab.

This isn’t accidental. UA seems content positioning HOVR for:
• Beginner runners needing durability over bounce
• Budget-conscious buyers (most HOVR shoes sit well below $150)
• Casual athletes who prioritize the UA brand over performance

The limited success of sponsored runners like Sharon Lokedi tells the story – when your foam can’t compete with modern PEBA or even good EVA blends, you’re not winning races. While HOVR works for light daily training, serious runners will find better options nearly everywhere else. Until UA invests in real foam innovation, they’ll remain an afterthought in the running world.

Under Armour HOVR+ (TPU)

Under Armour finally admitted what runners knew for years – their EVA-based HOVR foam wasn’t cutting it. Enter HOVR+, their long-overdue TPU foam that actually delivers proper energy return. Using a process similar to Adidas’ Light Boost (but without the branding), this new compound gives UA shoes something they’ve desperately needed: a lively, responsive underfoot feel.

The good? TPU brings better bounce, improved durability, and that springy sensation missing from the original HOVR. The bad? That classic TPU weight penalty. When we laced up the Infinite Elite, the extra cushioning was noticeable – but so was the shoe’s clunky feel on the run.

Here’s the thing: This is UA’s first real step toward competing in performance running. If they can refine HOVR+ to shed weight while keeping that TPU responsiveness? They might finally become more than just an “also-ran” brand. For now though, it’s progress – just don’t expect to see elites ditching their Nikes or Adidas for these anytime soon.

Mizuno Enerzy (TPE)

While 2020 was a washout for racing, it quietly delivered one of the most underrated foam breakthroughs: Mizuno Enerzy. After two years of R&D, the Japanese brand unveiled this TPE-based midsole (chemically similar to Puma’s Nitro) that outperforms standard EVA by 17% in softness and 15% in energy return—a legit leap forward we felt in every stride.

Why Enerzy Stands Out:

• Workhorse durability that laughs at daily mileage
• Goldilocks cushioning—soft enough for comfort, firm enough for responsiveness
• Versatile enough for everything from tempo runs to long, easy miles

The catch? It’s not the lightest foam out there. But for runners who prioritize longevity and consistent performance over featherweight racing specs, Enerzy delivers where it counts. While it never got the hype of PEBA superfoams, this unsung hero proves sometimes the best innovations come in dependable daily-trainer packages.

Mizuno Enerzy Lite (Nylon)

Mizuno’s Foam Lineup: Where Enerzy Lite Fits In

Mizuno’s foam hierarchy is clear: Enerzy Lite+ reigns supreme for performance, while standard Enerzy handles daily training duties. Sandwiched between them is Enerzy Lite—the “middle child” that sacrifices some plushness and bounce from its premium sibling but delivers crucial stability where needed.

We’ve spotted this nylon-based foam in select shoes like the Wave Rebellion Pro 2, where it plays a key supporting role. Positioned beneath the plate in Mizuno’s super shoe, it provides:

• Essential stability for that towering stack height
• Controlled compliance (softer than standard EVA, firmer than Lite+)
• Targeted performance where pure softness would be a liability

It’s not the star of the show, but Enerzy Lite proves even “compromise” foams can be engineering triumphs when used strategically. For Mizuno, that means letting Lite+ handle the bounce while Lite keeps the ride from getting too wild.

Normal Expure (EVA)

Born from trail legend Kilian Jornet and Spanish footwear innovator Camper, NNormal isn’t just another running brand—it’s a sustainability mission with legs. Their debut EExpure foam reflects this ethos: a nitrogen-infused EVA that’s shockingly light yet built to last. In fact, it might be the most durable supercritical foam we’ve seen—perfect for shoes like the Kjerag, designed with replaceable outsoles to fight disposable culture.

What We Know About What’s Next:

• A TPU-based foam is in development (likely for heavier-duty models)
• A PEBA compound is rumored for future racers like the Kboix
• Both align with NNormal’s “build less, innovate more” philosophy

For now, EExpure sets a strong foundation—proof that eco-conscious materials can compete on performance. And with Jornet’s relentless standards? We’re betting NNormal’s next foams will turn even more heads.

Topo ZipFoam

Topo’s got Pebax in its premium shoes, but for most of its lineup, the brand leans on ZipFoam an EVA-TPU blend that splits the difference between affordability and performance. Think of it as Boost’s less bouncy cousin: the TPU adds durability, but the extra weight keeps it firmly in daily trainer territory.

The Good:

• Tough as nails perfect for high-mileage runners
• More responsive than plain EVA (thanks to that TPU kick)
• Fits Topo’s natural-foot ethos without breaking the bank

The Catch:
It’s not winning any foam awards. While dependable, ZipFoam lacks the lively feel of modern supercritical EVA or nitrogen-infused compounds. If Topo wants its daily trainers to truly compete, a lighter, springier update should be next on the R&D list.

For now? It’s a solid pick for runners who prioritize durability and fit over cutting-edge bounce which, let’s be honest, is exactly what Topo’s loyal fans love about the brand.

Which standard foam should you choose?

Vintage foams

Rewind a few decades, and running shoes lived in a world dominated by one material: EVA foam. Since its 1970s debut, this lightweight, cushioned compound reigned supreme—a massive upgrade from the clunky polyurethane midsoles it replaced. Brands tinkered at the edges, blending EVA variants or adding gimmicks like ASICS’ gel pads or Nike’s air pockets, but real innovation? That remained elusive.

This was an era of baby steps, not breakthroughs. Shoes got slightly lighter or marginally bouncier year after year, but no foam truly transformed the running experience. The seismic shifts we’d later see with Adidas’ Boost (2013) or Nike’s ZoomX (2017)? Unimaginable at the time. Runners simply accepted that shoes were heavy, broke down quickly, and offered modest energy return at best.

Looking back, it’s striking how stagnant foam tech was before the 2010s—and how dramatically the right materials (TPU, PEBA) would rewrite the rules. What felt like “good enough” for decades suddenly became obsolete almost overnight.

Winter running: How it affects your running shoes

Temperature Stability of Running Shoe Foams

(Durometer measured in Shore A Hardness “HA”; lower = softer)

Premium Foams (High-Performance)

• Premium foams (PEBA, TPEE) remain remarkably stable in cold temps, with hardness increases under 9%.
• ZoomX (PEBA) is the softest at room temp and stays pliable even when frozen.
• Lightstrike Pro (TPEE) shows the least change, ideal for cold-weather racing.

Standard Foams (Daily Trainers)

• Standard foams (EVA, TPU blends) harden significantly in cold temps, especially:
• FuelCell (TPU/EVA): Over 2x harder when frozen—loses its signature softness.
• EVA-based foams: Avg. +30–40% harder, risking discomfort in winter runs.
• Worst for cold weather: FuelCell and PWRRUN+ (TPU blends).

Why This Matters

1. Performance Consistency: Premium foams (PEBA/TPEE) maintain energy return and cushioning in all conditions.
2. Winter Running: Standard EVA/TPU shoes may feel “dead” or harsh below freezing.
3. Durability: Foams that harden excessively are prone to cracking or losing rebound over time.

Pro Tip: For sub-zero runs, prioritize PEBA-based shoes (ZoomX, FF Turbo) or TPEE (Lightstrike Pro). Avoid TPU/EVA blends if temps drop below 40°F (4°C).

Visual Comparison

(Room Temp vs. Freezer Hardness)

Premium Foams:  
ZoomX        ██████████░░ (+8.5%)  
Lightstrike P ██████░░░░░ (+4.4%)  

Standard Foams:  
FuelCell      ████████████████████ (+115%)  
FFBlast+      █████████░░ (+36%)  

How To Make The Shoes Rest And Recover?

That friend who insists you should “let your shoes rest” between runs? Turns out they’re onto something and we’ve got the lab tests to prove it.

Dow Chemical put foams through brutal 22-hour compression marathons, then tracked their bounce-back over 24 hours. The results? Eye-opening:

• Regular EVA surprises with quick short-term recovery (beating EVA+OBC at 30 minutes)
• But long-term? EVA+OBC and E-TPU dominate, eventually rebounding to 90% recovery after 5 days
• Standard EVA flatlines at 70% decent, but not great

Then came the 100,000-cycle stress test at 40°C (think summer long runs). Here’s where it gets wild:

• EVA’s the tortoise steady but limited, never regaining full spring
• E-TPU/EVA+OBC are hares slow starters (struggling for 100 hours) but ultimately champions of resilience

The Sweet Spot for Shoe Rotation:

• 48-72 hours between wears for non-EVA shoes
• 5 full days for optimal foam rebound
• The harder/longer you run, the more recovery your shoes need

Treat your shoes like your muscles give them time to bounce back, and they’ll reward you with better cushioning, longer lifespan, and happier legs. Your future self (and your wallet) will thank you.

Are Higher Shoes Better?

The running shoe world has gone vertical what was once extreme (remember the shock over Adidas’ 50mm Prime X or Kipchoge’s illegal Alphafly prototype?) is now commonplace. But before you jump on the max-stack bandwagon, here’s what the science and real-world running tells us:

The Pros of Going Tall:
✔ Energy return king: That thick slab of PEBA or supercritical foam does propel you forward
✔ Impact absorption: Your joints will thank you on long runs (see: ASICS Nimbus 25)
✔ Race-day advantage: For marathoners, 35-40mm stacks are now the golden standard

The Reality Check:
✖ Stability trade-off: Overpronators in 50mm clouds? Recipe for wobbling and wasted energy (try the Hoka Gaviota 4 instead)
✖ Speed limitations: Mile/5K specialists lose agility in towering shoes <30mm lets you corner like a sports car
✖ Ground feel vanishes: Not ideal for runners who prefer natural foot feedback

The Bottom Line?
The market wants pillowy protection, so brands keep building higher. But smart runners match stack height to their:
• Footstrike (neutral vs. pronated)
• Race distance (marathon vs. track)
• Personal preference (cloud-like vs. connected)

Because in the end, the “best” stack isn’t the tallest it’s the one that makes your stride smoother and faster.

Why Is Investing In A Good Shoe Foam Can Be Good?

Most runners focus on how premium foams make them faster, but the real game changer might be what happens after your run. Elite athletes consistently report that shoes with foams like ZoomX significantly reduce next day soreness (DOMS) and muscle fatigue. For high mileage runners logging 100+ kilometers weekly, this isn’t just nice to have, it’s essential for sustaining training loads without breaking down.

That said, if you’re running 40-50 kilometers weekly, the difference between React and ZoomX might feel subtle during your runs. But here’s the perspective shift:

Consider the cost comparison:
• One physical therapy session: 50−50−150
• Price difference between React Infinity and ZoomX Invincible: Often less than one PT visit

While these shoes absolutely aren’t PT substitutes, the math gets interesting when you realize premium foams:

1. Reduce joint stress during high mileage
2. Accelerate recovery between sessions
3. Provide better energy return (bonus speed)

For serious runners, that’s not just a shoe upgrade, it’s an investment in sustainable training. The key is matching the technology to your actual mileage and recovery needs rather than chasing specs alone.

What Is The Lifespan Of Shoe Foams?

Foam longevity isn’t one size fits all. Several key factors determine how quickly your midsoles break down:

1. Foam Type Matters
Most premium foams (especially high energy return PEBA) sacrifice durability for bounce, though exceptions like Adidas Lightstrike Pro exist. Traditional EVA and TPU? Those can practically outlive your running career.

2. Your Body and Running Style
Heavier runners and those logging fast paces (with longer strides or higher cadence) accelerate foam breakdown.

3. Environmental Factors
Extreme heat or cold stresses foam cells. Mild temperatures help preserve midsole life.

4. Perception Is Personal
Some runners retire shoes when performance drops 10%. Others happily clock 1000+ km once the “magic” fades around 150 250 km.

What the Research Says
• A 2023 study (Rodrigo Carranza) found PEBA and EVA perform similarly after 450 km
• But 2024 research (Burns/Joubert) shows PEBA maintains advantages longer
• Our take: For racing, avoid premium foams beyond 200 km to guarantee peak performance

Pro Tips for Extending Foam Life
• Prioritize shoes with thicker rubber outsoles (check our lab tests for specs)
• Minimize exposed midsole areas
• Rotate multiple pairs to allow foam recovery

Remember: A “dead” training shoe might still have months of life for easy runs. The key is knowing when to retire them from speedwork.

Best Techniques For Midsole Manufacturing

After reading our guide, you might wonder how midsoles actually get made. Nearly all running shoe midsoles are created using one of two manufacturing processes, each with distinct advantages.

Compression Molding: The Traditional Workhorse
This cost effective method has been shaping running shoes for decades. Workers preheat plastic or rubber materials before placing them in heated molds. Under intense pressure, the material takes the mold’s shape as it cools.

Why brands love it:
• Perfect for combining multiple foam types in one midsole
• Allows precise control over density (critical for EVA, TPU and PEBA tuning)
• Delivers consistent quality for high volume production

Injection Molding: The Speed Solution
Here, manufacturers inject heated material directly into molds with blowing agents, creating lighter, airier foams as the material cools.

Key benefits:
• Faster production cycles than compression molding
• Enables intricate midsole designs and textures
• Ideal for creating less dense, softer feeling midsoles

The Bottom Line
Injection molding wins for speedy production and lightweight designs, while compression molding remains the gold standard for precision and material quality. Most brands use both methods strategically across different shoe lines.

How To Identify a Compression Molded Midsole

1. The Dot Test
Examine the midsole surface closely. Those tiny raised dots you see (like on the New Balance More v4) are classic fingerprints of compression molding. They form when material gets pressed into mold cavities under extreme heat and pressure.

2. Complex Shape Clues
No dots? Check the midsole geometry. Intricate designs with precise edges and contours (think Hoka Arahi 7’s sculpted base) almost always indicate compression molding. This method allows for sharper detailing than injection molding.

Why It Matters
• Compression molded midsoles often have more consistent density
• The process allows multi-material construction (like dual-density foams)
• Typically results in longer-lasting cushioning

Non-compression molded midsoles

In 2023, Adidas shattered conventional midsole manufacturing with their Lightstrike Pro Evo foam in the Adizero Adios Pro Evo 1. Forget compression molding or gas injection – this radical approach borrows from aerospace and automotive engineering:

The CNC Machine Method

1. Massive foam blocks are created as raw material
2. Precision CNC cutting shapes each midsole individually
3. No molds or gases are used in the process

Why This Matters
✓ 50g lighter than traditional midsoles (a huge leap for racing shoes)
✓ Perfect density consistency (no uneven firmness from edge to center)
✓ Unmatched precision in midsole geometry

The Catch
• Currently only viable for elite “hypershoes” due to extreme costs
• Production speed can’t match conventional methods
• Limited to PEBA and other high-end compounds

While this technology won’t replace standard methods soon, it proves what’s possible when running innovation meets cutting-edge manufacturing. For now, enjoy that space-age feel – just prepare for the premium price tag.

Conclusion

The running shoe industry has experienced only two true foam revolutions in recent history – Adidas’ Boost TPU foam in 2013 and Nike’s ZoomX PEBA foam in 2017. While these breakthroughs set new standards, recent advancements suggest we’re now in an era of refinement rather than revolution. The latest innovations like Adidas’ Lightstrike Pro Evo have pushed boundaries through manufacturing breakthroughs rather than new materials, using CNC machining to create unprecedentedly lightweight PEBA midsoles. Saucony’s upcoming IncrediRUN foam promises impressive 97% energy return when it launches in 2025, while PUMA’s transition to aliphatic TPU in their Nitro Elite line claims superior fatigue resistance.

However, with World Athletics regulations capping stack heights at 40mm and restricting shoes to a single carbon plate, the potential for another ZoomX-level disruption appears limited under current rules. Instead, brands are focusing on incremental improvements – perfecting manufacturing techniques like Adidas’ CNC process, optimizing existing materials, and chasing marginal weight reductions. The Adizero Adios Pro Evo 1 demonstrates this perfectly, achieving remarkable sub-5-ounce weight through precision engineering rather than material breakthroughs. For now, runners can expect steady progress rather than seismic shifts, at least until the next major material science discovery emerges.

Author

Mohammad Yousaf

As a business student, Mohammad was thoroughly impressed with where the secondary market was heading for sneakers. He quickly realized that what used to be considered as a side hustle, was now the main income stream for many. He has studied the game ever since.