The ultimate guide to running shoe foams

Running shoe companies aren't as transparent as we'd love, making it difficult for both casual and advanced runners to gather detailed information about specific running shoe foams. 

Recognizing this challenge, we've done an extensive guide for you, presenting our findings and knowledge about running shoe midsoles in a clear and comprehensive manner.

What makes foam so important for running shoes?

The midsole in a running shoe is undeniably the most crucial component, as it enables every runner to cover greater distances and achieve faster speeds while minimizing the risk of injury.

Running shoe foam works as a shock absorber, cushioning the impact on your feet with each stride. This reduces stress and potential damage to joints and muscles, allowing for increased comfort and decreased fatigue. In other words, we can sustain a faster pace, run longer distances and recover faster.

Choosing the perfect foam for your running shoes is essential, as it can significantly influence your performance and recovery. Whether you're striving to demolish your PB in a short race or seeking enhanced injury prevention and reduced fatigue through increased impact protection, the right foam and stack height can make a world of difference.

Running shoe foams

Disclaimer: Due to the vast variety of running shoe foams currently available, some may be excluded (Chinese brands, entry-level or old EVA foams, etc). Please note that some foams may be released after the publication/updates of this guide and may not be included. Additionally, we will exclude non-foam cushioning systems, such as Air from Nike or GEL from ASICS.

Due to the many running shoe companies out there, it would take forever to go over every type of foam used in shoes. This is especially true if we consider all the discontinued or basic foams, which make up 99% of the market and are just plain EVAs.

However, we still made a big effort to cover with detail as many foams as we could. We've dedicated entire sections to most of them, but we'll also just mention a few below. And we'll regularly update this guide!

Premium foams overview

Standard foams overview

Premium foams

The world of running shoes was transformed with the introduction of Nike's ZoomX foam in 2017, even though it had already been worn by some pro athletes—Kipchoge, Rupp, Lilesa— throughout 2016. It was the first true super foam, boasting an energy return that exceeded 90% in nearly every test, and Nike backed it with much-needed scientific evidence. And contrary to what many believe, ZoomX it's not a Nike invention, but product called ZOTEK® PEBA from the UK-based company Zotefoams.

The latest high-performance running shoe foams have a unique chemical structure, consisting of numerous hydrogen bonds between the polymer strands. This special structure enhances energy return and bounce, as shown in this 2018 study. The findings revealed that Boost foam delivered a 75.9% energy return, while the ZoomX-equipped Vaporfly prototype—named Vaporfly 3% in that moment—provided a massive 87.0% return. Another two studies in 2023 and 2024 confirmed the improvements of PEBA when compared to EVA, especially when paired with carbon plates.

So, what sets a premium foam apart from the crowd? Superior midsoles with this foam have 3 clear advantages. They...

• offer an impressive energy return into the 80-95% ballpark;
• possess fantastic leg-saving features. Put simply: logging a 20-miler in one of these shoes feels more like a 10 or 15-miler in your reasonably-good daily trainer;
• are super fun to ride!

However, there are a couple of drawbacks to consider:

• Durability may take a hit—these premium foams tend not to last as long as their standard counterparts.
• Purchasing a pair of shoes with premium foam will come with a premium price tag. Most of these shoes, even with discounts, often hover well above the $100 mark, sometimes soaring as high as $200, $250, or even $300.

But let's get back to it. As we mentioned before, the ZoomX foam changed everything. This innovation gave Nike a two-year advantage over its competitors—a groundbreaking edge in the intensely competitive world of running shoes. Finally, though, many brands caught up with the Oregon-based company, resulting in a wide range of premium foams available for you.

Interestingly, while carbon-fiber plates are often hailed as the ultimate performance-enhancing feature, most of the improvement actually comes from the foam. This is supported by various scientific publications, such as those from 2019 and 2021, where the only shoes that matched the Vaporfly's performance had what we consider "premium foams." In contrast, others like the RC Elite v2 (FuelCell) and Brooks Hyperion Elite 2 (DNA Flash) lagged significantly behind the best.

Now, let’s talk about ‘em, beginning with the one that started it all.

Nike ZoomX (Pebax)

We have to credit Nike and say that they made the original super foam. Period. And ZoomX is still arguably the best in terms of energy return.

Before ZoomX, the best-performing foam in the world was Adidas' Boost, which launched in 2013 and revolutionized long-distance running. It achieved several WRs and was arguably the first foam ever to surpass 75% in energy return. Now, it’s almost outdated.

ZoomX it’s a foam made from Pebax. And as you are going to read this word a lot, let’s clarify this once and for all—Pebax is a trademarked and patented variation of PEBA (Polyether Block Amide) invented by Arkema, an industry-leading French company. It’s a class of thermoplastic elastomers characterized by their alternating hard and soft segments, which give them a unique combination of flexibility, resilience, and mechanical strength. In other words: it’s bouncy, soft and light!

Over the years, users and experts have noted that ZoomX has undergone significant changes. While we might not cover every detail, we can distinguish between various ZoomX blends:

1. From 2017 to 2021, ZoomX was incredibly soft in the first Vaporflys, giving an almost magical feel, but it suffered from low durability—which was a constant complaint from users given the cost of these shoes. The foam developed creases quickly, and after about 200 or 300 km, it suddenly felt "dead." Other running shoes featuring this 1.0 version of ZoomX included the Nike Air Zoom Alphafly Next%, Nike ZoomX Invincible Run, and Nike Pegasus Turbo 2.
2. In 2021, Nike launched the Vaporfly Next% 2, and everyone almost immediately reported that it felt firmer than the original, despite supposedly being the same midsole. A similar situation occurred with the Nike ZoomX Invincible Run 2 and Alphafly Next% 2, launched in 2022. These shoes featured a firmer yet more durable ZoomX, allowing runners to get more mileage for their money. The exception to the rule in 2022 is the Streakfly, which is really soft despite being launched in the same year.
3. In early 2023, Nike released the highly anticipated Vaporfly 3 and ZoomX Invincible 3. While some reports suggested a softer feel, our lab measured the ZoomX in the Invincible v3 to be 16% firmer than the one in the previous version.

Nike also features eco-friendly recycled ZoomX in its Next Nature lineup, such as the latest Pegasus Turbo. Unfortunately, the recycled ZoomX is heavier, firmer, and provides less energy return, so we don't classify it as a premium foam. However, it does outperform React and, of course, any standard EVA (ethylene-vinyl acetate) in the market.

In summary, if you're seeking record-breaking energy return plus a springy ride without needing a break-in period, ZoomX is a reliable choice. Just keep in mind that it may not be the most long-lasting midsole out there and MSRP of ZoomX-equipped shoes tends to be on the expensive side.

ASICS FF Turbo+ (PEBA)

In 2024, ASICS launched the FF Turbo+, an advanced upgrade from the original FF Turbo, highlighting increased resilience and responsiveness. This latest version is noticeably bouncier and softer, and it even comes with the added advantage of being lighter than its predecessor. The enhancement results from a refined supercritical manufacturing process, which introduces more nitrogen into the foam, leading to larger bubbles and a more uniform texture throughout the material.

This development not only improves the feel underfoot but also transforms the overall performance of the new ASICS shoes incorporating this foam. Though the name implies a minor update, the changes are substantial. 

We verified these improvements firsthand in the lab with the ASICS Superblast 2 and the ASICS Metaspeed Sky Paris, where the new foam contributed significantly to a superior running experience. The difference in how the shoe handles and responds while running is palpable and impressive.

ASICS FF Turbo (Nylon)

Commonly known as FF Turbo, this innovative foam was one of the first to truly level the playing field against Nike's ZoomX.

Unfortunately, ASICS hasn't disclosed the materials used to create FF Turbo, but we do know that it's a nylon-based or PEBA midsole—think of it as the store brand for Pebax—which is quite similar to Pebax in terms of energy return and bounciness. However, it's noticeably firmer and more stable, so keep that in mind if you're considering this alternative.

We have analyzed in our lab many FF Turbo shoes, and we can confirm that this foam is firmer than ZoomX. For instance, the ASICS Metaspeed Sky+ was measured at 28.8 HA in our durometer, which is 34% firmer than the Nike Vaporfly Next% 2.

Interestingly, this foam emits a strong glue-like scent, particularly when fresh out of the box—this is completely normal and there's no cause for concern. Additionally, Asics boasts that FlyteFoam Blast Turbo is an impressive 45% lighter and 36% bouncier than your average EVA midsole.

Adidas Lightstrike Pro (TPEE)

Due to its large size and extensive elite roster, Adidas had a rough time from 2017 to 2020. Initially, they rushed and tried with the Adizero Pro, a carbon-plated shoe featuring a mix of Boost and Lightstrike, two standard foams. However, it quickly became clear that it was no match for the Vaporfly.

Eventually, they launched the original Adizero Adios Pro, internally referred to as Majambo, which featured their new top-tier foam called Lightstrike Pro, which is manufactured by Shincell in China. And boy did they deliver.

Unlike most premium foams made of PEBA, Lightstrike Pro is built from TPEE (Thermoplastic Polyester Elastomer), which offers some unique properties:

• Amazing durability: While many premium foams wear out relatively quickly, Lightstrike Pro performs at its best even after 200 or 300 kilometers. We've received reports of some shoes being used for intervals or long runs with more than 1,000 km.
• Lightstrike Pro exhibits a unique behavior compared to other premium foams. It requires a short break-in period of at least 2-3 runs, and the shoe will be at its best between 50 km and 250 km in terms of energy return. Log your miles first! 
• The ride is on the firmer side compared to many other super foams, but it becomes considerably softer in summer.

Although not yet scientifically proven, it is believed that Lightstrike Pro has a slightly lower energy return compared to ZoomX. While this may be true, the numerous records and World Marathon Majors wins achieved by this foam—like the podium sweep in Boston 2023—suggest that any difference is minimal. Our own testing supports this conclusion.

In 2023, Adidas unveiled the Adizero Adios Pro Evo 1, a limited-edition shoe primarily designed for elite athletes. To adhere to World Athletics regulations, a 521 pairs were made available to the general public in an initial release. This shoe introduces Lightstrike Pro Evo, which is less dense and incredibly light.

The innovative Lightstrike Pro Evo foam is crafted through a groundbreaking non-compression molding technique and a supercritical process. Unlike traditional methods, the foam is produced in large blocks and then precisely shaped with CNC machines—an industry-first approach. This advanced—and incredibly expensive—manufacturing technique significantly reduces the weight by 50g compared to the Adios Pro 3, while also boosting energy return... and price.

In 2024, Adidas is reformulating Lightstrike Pro for its new racer, the Adios Pro 4. They're still using TPEE as its main component but adjusting the formulation to make it airier and softer. While that means a substantial decrease in durability, the overall plush feel and softness are expected to be greatly improved. Running shoe foams, much like life, involve trade-offs.

Saucony PWRRUN PB (Pebax)

The American brand also has an agreement with Arkema to use Pebax, but it employs a different formulation and format compared to ZoomX. PWRRUN PB is composed of tiny pellets—similar to Boost—rather than a single block.

Boasting a distinctive soft yet responsive feel, impressive durability, and great energy return, PWRRUN PB is considered a fantastic all-rounder but it’s slightly behind the top performers. Nevertheless, it ranks among the best foams, and Saucony has achieved remarkable success incorporating it into the Endorphin series.

This pellet-based design features a network of grooves and flex points that enable the foam to adapt to the foot's movements, delivering a customized fit and enhanced comfort.

Interestingly, PWRRUN stands for "Performance Welded, Responsive, Resilient, UNderfoot foam," and PB is derived from Pebax.

Saucony PWRRUN HG (Pebax)

This is the latest premier foam from Saucony, and one of the most responsive out there. At the moment, it is only featured in the Saucony Endorphin Elite, the Saucony Endorphin Pro 4 and the Terminal VT track spike.

The HG variant of PWRRUN is clearly firmer and more stable. Let’s say that it’s more Lightstrike Pro than ZoomX.

Although Saucony hasn’t disclosed publicly how PWRRUN HG is made, we assessed that this foam is a supercritical inflated Pebax built like ZoomX, so expect a similar behaviour and performance underfoot.

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

Puma’s premier racing foam is a rarity. Although the German company hasn’t disclosed the formulation publicly, we do know that it’s a blend of PEBA and EVA infused with nitrogen. 

The approach that Puma followed by mixing PEBA and EVA is to get a mix of performance, durability and lower cost of fabrication. That puts the foam one step behind the top in terms of energy return, but the increase in durability is well received by some runners, especially those who want this shoe for training purposes. 

That, combined with the renowned resilience of the PumaGrip outsole compound, makes Puma shoes a fantastic option for training, but not the best for racing, and that’s also why you won’t see many Puma super shoes in long distance races.

In late 2023, PUMA introduced the Fast-R Nitro Elite 2 and updated the Nitro Elite formulation to A-TPU (Aliphatic TPU). According to the brand, this new material theoretically delivers a significant boost in energy return, reaching an impressive 93%. We definitely found boucier than ever in our test runs.

It's still too soon to know, but we think that A-TPU could be the next breakthrough in running shoe superfoams, offering a viable alternative to PEBA with superior long-term performance. It maintains its resilience better throughout a marathon and has enhanced UV resistance that prolongs its shelf life.

In terms of bounce, A-TPU matches or even exceeds PEBA, with PUMA reporting up to 93% energy return. However, its elastic feel doesn't create the same "magical" sensation as PEBA, so you may be running, wondering if it's as fast as the Vaporfly, only to check your watch and confirm that indeed, it is!

Hoka Unnamed (PEBA)

After over three years of anticipation, Hoka finally unveiled its first genuine supershoe in 2023: the Hoka Rocket X 2, featuring a PEBA-based foam.

Hoka has been rather tight-lipped about this innovative foam, which, to this day, remains unnamed. Despite reaching out to them, we have yet to receive any information. However, we do know that it's a dual-density PEBA foam, boasting exceptional bounciness that falls somewhere between ZoomX and FF Turbo in terms of feel—neither too soft nor too firm.

We expect Hoka to soon divulge further information about this midsole—please name it—and to launch new racing and training models incorporating this advanced midsole. In fact, Hoka has already started utilizing this PEBA foam in training models such as the Hoka Mach X.

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

As two French big companies, it made perfect sense for Decathlon and Arkema to partner up when the popular retailer decided to create their very first supershoe, the Kiprun KD900X, which was launched in 2022 and features VFOAM technology.

VFOAM is a Pebax-based midsole formed by pellets—in the style of Saucony’s PWRRUN PB. It’s bouncy and light, but the energy return is slightly below the best premium foams.

Decathlon offers probably the cheapest way to enter the world of premium foams, at least if we take into account MSRP and we forget about the usual discounts in some major brands.

By 2024, the French company upgraded the KD900X LD with VFOAM PLUS, a new foam that delivers a softer feel underfoot. This updated formulation combines Pebax and EVA and moves away from the Boost-like pellet structure. Although this change might appear technically regressive, Decathlon likely views it as a strategy to boost durability.

Mizuno Enerzy Lite+ (PEBA)

The Japanese brand has recently entered the supershoe market, and one of the reasons they were not competitive in this space earlier was because they lacked a truly high-performance foam. However, now they have Enerzy Lite+.

Enerzy Lite+ is a type of PEBA foam that has a soft, cloud-like feel similar to the first versions of Nike's ZoomX. However, Enerzy Lite+ is really unstable, which has probably prevented Mizuno from using it in a full-length midsole. Instead, they combine it with a more stable section of non-premium Enerzy Lite foam in their jaw-droppingly-impressive Wave Rebellion Pro 2.

Mizuno Enerzy NXT

In 2024, Mizuno introduced a new foam that initially didn't excite us—another EVA-based material, which hardly seemed like a leap in innovation. However, Mizuno assured us of its high quality, comparing it to the elite Pebax-based foams.

Upon testing it with the Mizuno Wave Sky 8 in our lab, we were pleasantly surprised. This wasn't just another run-of-the-mill EVA; it was exceptionally soft, impressively bouncy, and significantly more enjoyable. Congratulations to Mizuno for innovatively enhancing EVA into something far beyond the ordinary with a fantastic supercritical formulation.

Reebok Floatride (Pebax)

It's not often that you see many Reebok running shoes out there in the roads, right? Honestly, I can hardly recall the last time I encountered someone wearing them while running, and I always take notice of people's footwear.

Despite its rarity, Reebok offers one of the more affordable ways to experience a Pebax-based midsole. However, there's a catch: Reebok uses the name "Floatride" for two distinct midsole types and it can be easily confused:

• Floatride: A Pebax midsole featured in premium models.
• Floatride Energy: A more budget-friendly non-premium, TPU-based midsole—similar to Boost—found in models such as the Energy 5.

By the way, Pebax's impressive performance is evident when Reebok claims that it's up to 50% lighter than their previous EVA foam, all while delivering significantly more energy return.

Li-Ning BOOM (Pebax)

With some Chinese brands making appearances and endorsing some elite athletes in recent times, it’s probably Li-Ning the one that has the best premium foam in their high-performance shoes.

In some funny Chinese-style, the name of the midsole is BOOM. It’s a Pebax-based supercritical foam, and we’ve even seen some elite runners enjoying this ZoomX-esque midsole in the Feidian series; for instance, in 2023 Seville Marathon, the winner—with a respectable 2:04:59—and the third place were in Li-Ning shoes.

With that said, good luck buying those in the USA or Europe. They’re mostly restricted to the Chinese market, and while you can get your hands in those importing them, it’s probably not worth the price after customs taxes with so many alternatives that you can buy in five minutes from your home.

On Helion HF

On burst onto the running scene fashionably late, but made an impact that's hard to ignore. Boasting elite athletes like Mario García Romo and Hellen Obiri on their roster, the Swiss brand upped the ante with a new addition: the Helion HF midsole. This state-of-the-art foam, crafted from Arkema's Pebax, promises unparalleled performance.

While its ultra-reactive nature ensures impressive strides on the track and road, it does trade off some durability. On advises runners with a note in the box of their Helion HF shoes: "Lifespan = four marathons (+ infinite memories)".

We anticipate seeing more of On's footwear range featuring the Helion HF (Hyper Foam) in the next years, though as of now, it remains a select offering for just a few models like the Cloudmonster Hyper and the Cloudboom Echo 3.

New Balance FuelCell [2024-] (PEBA / PEBA + EVA)

New Balance has made a late entrance into the superfoams league with their latest FuelCell version. It retains the plush feel of the original non-PEBA FuelCell while delivering exceptional energy return. In essence, this is the FuelCell upgrade we've all been waiting for.

The SuperComp Elite v4 is the inaugural model to feature this advanced FuelCell foam, a shoe we've thoroughly evaluated in our lab. Future releases, such as the SuperComp Pacer, are set to follow suit. However, for some models like the Rebel v4, New Balance uses a mix of PEBA (20%) and EVA (80%) under the same FuelCell label, which could be confusing.

Although a unique name could have clarified this transition, the introduction of a FuelCell variant synonymous with elite energy return—in select models—is undoubtedly thrilling news for us.

Which premium foam should you choose?

While you might already guess the ideal foam for your running style or preferred distance, let's simplify things even more by selecting some foams and models based on your specific needs.

Standard foams

A standard foam, as per our definition, is any modern foam that delivers lower energy return when compared to premium foams. Despite their limitations, standard foams hold some advantages over premium foams:

• They are significantly more affordable to manufacture, enabling brands to offer these shoes at substantially lower prices, even below $100 in some cases. 
• Durability is a key strength, with many shoes crafted from standard foams easily surpassing the 1000 km mark.
• These foams often provide enhanced stability, making them ideal for runners seeking extra support.

However, there are also some clear disadvantages:

• Energy return is in the 60-80% ballpark, nowhere as close as that of premium foams (+85%).
• Most standard midsoles are bricks in winter. For example, a Nike ZoomX Invincible Run 3 becomes 10.3% firmer after 20 minutes in our freezer, while its standard-foamed counterpart, Nike React Infinity Run 3, stiffens by a whopping 62.5%. You can learn more about flexible vs. stiff shoes in our in-depth guide.
• High-mileage runners may find that these foams lack the leg-saving features often needed during high-mileage training blocks.

Skechers HyperBurst (EVA) / HyperBurst Pro (TPU)

Skechers has made significant advancements in the field of midsole technology with their innovative HyperBurst and HyperBurst Pro foams. By incorporating supercritical CO2 into the manufacturing process, they were able to create a lighter and more responsive EVA foam, which they dubbed HyperBurst. 

In fact, this method has influenced the running shoe industry, with many brands like New Balance or Brooks opting for nitrogen-infused foams to avoid licensing fees associated with Skechers' patented CO2 method, but using the same principles.

Left: A regular EVA midsole under the microscope, no bubbles.
Right: HyperBurst CO2-infused foam, with its characteristic bubbles that allow the EVA to be lighter and bouncier.
Source: Skechers patent

However, recognizing the obvious limitations of EVA-based foams, Skechers continued its pursuit of a better midsole by introducing HyperBurst Pro, which replaced EVA with TPU, further enhancing the foam's energy return, like Adidas did with Boost back in the day. While this new iteration is a step up from the original HyperBurst—hence the Pro name—it still doesn't quite measure up to be admitted into the premium foams club. Next time, fellas!

• HyperBurst: Supercritical (CO2) EVA: Soft, lightweight and durable.
• HyperBurst Pro: Supercritical (CO2) TPU: Firmer, responsive and heavier.

In summary, Skechers' HyperBurst and HyperBurst Pro midsoles are magnificent options for your daily runs, offering lightweight comfort and a fun ride. However, they may not be the ideal choice for those seeking their next PBs.

Despite their progress in foam technology, Skechers still has room for improvement if they aim to compete with any of the premium foams out there, and we wouldn’t be surprised if they launch a PEBA-based HyperBurst foam in the next few years. In fact, we really look forward to it!

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

The Boston-based company, New Balance, introduced FuelCell in 2019. This nitrogen-infused blend of EVA and TPU foam is similar to Skechers' HyperBurst Pro. Other sources point towards FuelCell being either supercritical TPU or EVA.

As previously mentioned, most brands avoid using CO2 to prevent paying licensing fees to Skechers. FuelCell offers approximately 70-80% energy return, which is behind the top-tier foams.

New Balance tends to alter the FuelCell formulation from model to model, resulting in a notably different ride between two FuelCell-equipped shoes. For instance, in our lab, we confirmed that the Rebel v3 is 31.6% softer than its predecessor, the Rebel v2. New Balance representatives also confirmed to us that they make big adjustments in FuelCell between models.

One significant drawback of the old FuelCell (the one manufactured until 2024) is that it becomes considerably firmer in cold temperatures. For example, the SuperComp Trainer becomes 57.4% firmer in cold conditions, while the Rebel v2 experiences a teeth-grinding 115.4% increase in firmness.

Nike React / ReactX (TPE + EVA)

In 2017, around the same time as ZoomX's release, Nike surprised everyone by introducing React. Initially, React was only available in basketball shoes, but a few months later, they launched the well-received Nike Epic React Flyknit. Now, it's everywhere.

React is a combination of Thermoplastic Elastomer (TPE) and EVA. The result is a foam that is resilient, soft, cheap to produce—Nike loves this for sure—and well-suited for training purposes, although it lacks the responsiveness and energy return needed for racing. That’s why Nike uses it for trail running shoes like the Pegasus Trail 4 or in daily trainers like the Pegasus 40.

But, what was the motivation behind React? Well, Nike had been using Lunarlon, a blend of EVA and NBR (Nitrile Rubber) foam, which significantly lagged behind Adidas' Boost technology. While ZoomX was already in production by 2016, its manufacturing costs were extremely high, and it was available only in limited quantities.

So, although React wasn't a groundbreaking revolution, it was a clear step forward for Nike. And we can confirm that React is a great all-rounder!

In 2023, Nike unveiled ReactX, the successor to their React technology. According to Nike's official data, this advanced foam offers a 13% increase in energy return and cuts the carbon footprint by a notable 43%. We lab-tested it in the Nike InfinityRN 4.

Nike Cushlon / Phylon (EVA)

Cushlon 3.0 currently stands as Nike's most favored EVA-based foam for their running shoes, surpassing the use of other materials such as the more economical SR-02, Phylon and the outdated Lunarlon.

Cushlon is essentially an evolved version of Phylon, enhanced by blending it with rubber in unique ratios. This modification not only retains the intrinsic qualities of Phylon but also elevates the cushioning experience, making Cushlon 3.0 a premium choice for runners seeking optimal comfort and performance.

Our tests showed that Cushlon foam is designed to be durable, maintaining its integrity and performance over many miles. This makes it a reliable option for daily trainers like the Nike Vomero 17. We think Nike is going to keep evolving Cushlon, which currently is in version 3.0, because it's really cheap to produce, lasts for enough miles and runners are not complaining at all.

On the other hand, Nike extensively employs Phylon in its footwear lineup, a type of CMEVA (Compressed Molded EVA) crafted from foam pellets. As the process implies, these pellets undergo compression, are then expanded through the application of heat, and finally cooled within a mold to take shape.

This particular manufacturing technique yields a midsole that not only excels in colder climates, maintaining its performance and comfort, but is also cost-effective to produce. This affordability is a significant advantage, allowing Nike to incorporate Phylon into entry-level, budget-conscious models such as the Revolution 7, although it's specifically tailored for those who prefer a firm feel underfoot.

Nike ComfiRide (EVA)

Nike’s latest addition to its foam lineup is ComfiRide, an affordable EVA-based foam now appearing in shoes retailing under $100. To put it simply, it’s the budget-friendly alternative to ReactX and even Cushlon.

We found that this foam is average in softness and should offer good durability, performing reliably without major issues. However, it falls short in energy return, which is expected for its price point. Currently, Nike has only included it in a few models, but we’re eager to test it in more shoes in the coming years and update our findings.

Adidas Boost (TPU)

Though it might not seem significant today, the Boost revolution was a game-changer in its time. It clearly outperformed all EVA-based foams and led to numerous long-distance records, such as Dennis Kimetto’s out-of-this-world and perhaps underrated 2:02:57 marathon time in Berlin 2014 while wearing the Adizero Adios Boost 2, or Joyciline Jepkosgei's 1:04:51 at the Valencia Half Marathon in 2017 with the Adizero Adios Boost 3. Now, let's talk about Boost!

Boost is not an Adidas invention, but rather one created by BASF (Badische Anilin und Sodafabrik), the world's largest chemical company. They were experimenting with an innovative technology called Infinergy, based on TPU (thermoplastic polyurethane), which delivered promising results. Adidas recognized the potential of this cutting-edge pellet-based method for creating a midsole when BASF presented it to them, and they just embraced the technology.

By today's standards, Boost is a comfortable-but-heavy midsole. However, back in 2013, it was a complete revolution, comparable to how we viewed ZoomX in 2017—it simply had no rivals. It was bouncy, soft and durable.

Although Adidas still utilizes Boost in some running shoes and in their sneakers and casual kicks, it is now considered somewhat obsolete for running, particularly due to its weight. That's why Adidas recently introduced the new, lighter, and less dense Light Boost evolution.

Adidas Light Boost (TPU)

"Better late than never" was our first thought when Adidas introduced the successor to Boost in 2023, named Light Boost. This new development is key because the primary issue with the original Boost was its weight. Adidas has now crafted an airier version of Boost that's 30% lighter.

And it truly lives up to its name. In our lab tests with the Ultraboost Light and the Ultraboost 5, we confirmed its reduced weight. Although it arrived on the market three or four years later than ideal, it's exactly what we hoped for—the same durable and dependable Boost, just 30% lighter!

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

When Adidas introduced Lightstrike to the world, they launched and marketed it as a TPU foam. Then, suddenly, they switched their minds and declared that Lightstrike was actually EVA:

• TPU: In the official press release for the Adizero Pro—which was a total flop—, the brand stated, "Lightstrike combines energy return and stability into one of the lightest TPU foams on the market."
• EVA: While promoting the brand new Adizero SL in another official press release, they said, "The lightweight Lightstrike EVA midsole frame provides maximum cushion and protection to the midsole construction."
• EVA: In 2023, Adidas launched Lightstrike 2.0, a new softer compound that will be featured in shoes like Adios 8 or Boston 12.

Some people believe that it's all the same EVA-based compound, but initially, it was mixed with some TPU, and now it's only EVA. While that's possible, we're inclined to think that the Germans simply changed their minds and switched from full-TPU to full-EVA, and that's why they're currently calling it Lightstrike EVA.

Unfortunately, all versions of Lightstrike are rather firm and dull, lacking bounciness and will only please those looking for a super-stable old-school ride.

Adidas Dreamstrike+ (PEBA)

You might be surprised to see us not categorize Adidas' PEBA-based Dreamstrike+ among the elite foams, but that's exactly where we stand with it.

The initial buzz around Dreamstrike+, featured in the Supernova Rise, was palpable—finally, a PEBA foam in an accessible daily trainer from Adidas! Yet, we found it more akin to TPU or supercritical EVA foams, lacking the standout energy return of counterparts like Lightstrike Pro or ZoomX, positioning it as a standard foam in our eyes.

Still, it marks a significant stride for Adidas. Dreamstrike+ boasts comfort, reasonable energy return, and impressive durability. Plus, with 20% bio-based content and a modern feel distinct from Boost, it's a noteworthy advancement in the right direction.

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

Years before Nike disrupted the running shoe market, ASICS was a strong competitor to Adidas' Boost technology, back in 2014. The Kobe-based brand ingeniously improved EVA properties to a level that we’re sure that, in a blind test, most runners would not recognize as EVA foam. Instead, they achieved this by blending EVA with OBC. But what the hell is OBC?

OBC, or Olefin Block Copolymers, is a thermoplastic elastomer known for its elasticity and toughness. ASICS mixes EVA with OBC to increase the elasticity of their FlyteFoam Blast foam, which in turn provides a more responsive and springy feel while running.

ASICS obtained the rights from Michigan-based company Dow to combine EVA and OBC technology, a patented method developed by Dow to enhance running shoe foams. To further improve resilience, the Kobe-based engineers cleverly incorporated Kevlar—a synthetic fiber used in bulletproof vests, which is renowned for its strength and durability—into the midsole. The result is a lightweight, bouncy, and fun foam that weighs up to 55% less than a standard EVA midsole. That’s how ASICS managed to deliver light-but-tall shoes like the Novablast 4.

In 2023, ASICS introduced the FF Blast+ ECO, which is crafted using a minimum of 20% bio-based materials derived from renewable sources, including residual waste from sugar cane processing. We've tested it and noticed it's slightly less energetic compared to the non-ECO version, but the difference is extremely subtle.

Truth is, these days there are only a few non-premium midsoles that outperform FlyteFoam Blast+, the latest iteration of FFBlast. Both expert and user reviews are overwhelmingly positive for shoes like the Nimbus 25 and Novablast 3, although durability may be a weak point.

There's also a lesser-known but really crucial feat