Saucony Endorphin Pro 4 review

We think the Endorphin Pro 4 is a prime choice for:

• Runners seeking a comfortable and slightly cheaper supershoe. The Pro 4 offers a smoother ride compared to its rivals, making it easier on the feet and the wallet.
• Enthusiasts of the Endorphin Speed series aiming for enhanced performance plus a carbon plate with a familiar feel.
• Marathoners seeking a reliable, long-lasting shoe for race day and fast-paced long runs, featuring an elite-level midsole.

Though the Endorphin Pro 4 has the makings of a supershoe, we noticed a modest dip in performance, a choice we think Saucony made to differentiate it from the Endorphin Elite, which boasts a full-length PWRRUN HG midsole and a lighter build.

Additionally, we believe there are superior choices for midfoot and forefoot strikers on the market. The Adidas Adizero Adios Pro 3 and Hoka Rocket X 2 not only provide a stable ride but also offer more forefoot cushioning and a quicker feel. And for unmatched energy return, the record-setting Nike Alphafly 3 is unrivalled.

Finally, if weight is a crucial factor for you, the Endorphin Pro 4 may disappoint. In this case, we think the Nike Vaporfly 3 is a better competition shoe.

We really believe this is one of the top racing shoes for heel strikers. Our lab data backs it up with the heel’s impressive 139 SA shock absorption. On the flip side, the forefoot registers a more average 103 SA, offering less protection for runners landing up front.

When we put the EP4 through our energy return test, we measured a strong 71.7%. That’s enough to earn its place among supershoes, but still trails behind the front-runners that have already pushed past the 75% threshold, like the Adios Pro 4 from Adidas.

A critique of the EP3 involved its cushioning, which was notably 5 mm below the World Athletics official limit.

This issue has been addressed in the new model, with a cushioning height of 38.1 mm, adding an extra 3.1 mm of foam. This boost is sure to offer significant support during the final miles of your next marathon.

Our calliper measured the forefoot at slightly below the 30-mm mark (28.6 mm).

This reading is satisfactory but might feel insufficient for forefoot strikers that want to tackle 26.2 miles.

We discovered that the Endorphin Pro 4 boasts an actual heel-to-toe drop of 9.5 mm, which is notably high. This confirms our belief that this shoe is a top choice for heel strikers.

While Saucony lists an 8-mm drop for this shoe, our measurements align with World Athletics official guidelines. For those curious about such differences, we've prepared an informative guide to explain these discrepancies.

Beneath the sockliner lies the true highlight—the midsole. Saucony's approach with the Endorphin Pro 4 marks a significant evolution from its predecessors.

This model introduces a brand-new, dual-midsole system, featuring a top layer of PWRRUN HG (same as the Endorphin Elite) and a bottom layer of the tried-and-true PWRRUN PB, with a carbon plate nestled in between.

The foundational foam layer, PWRRUN PB, has been a staple in every Endorphin Pro iteration. Crafted from 22.0-HA Pebax pellets, it guarantees enduring performance and a stable, well-balanced ride.

The headline feature of the Endorphin Pro 4 is the debut of PWRRUN HG foam in this series—a groundbreaking supercritical Pebax blend from Saucony, reminiscent of Nike's ZoomX, and utilised in the pricier Endorphin Elite.

Positioned above the carbon plate, this layer is a tad softer (18.5 HA) than PWRRUN PB and does not come in form of pellets. It avoids a too-soft, mushy sensation, opting instead for a springy, responsive feel that propels you forward with a quick and snappy rebound in each stride.

In the current world of rockered running shoes, the Endorphin Pro series stands out for its subtler rocker design, a trend the v4 continues.

We appreciate this approach in a market overwhelmed by extreme rockered designs, offering those who prefer a more traditional feel a perfect option in the EP4.

A quintessential supershoe must include a stiffening element in the midsole, and Saucony has chosen to continue with the S-shaped carbon plate, given its proven track record of success.

This carbon plate is central to Saucony's Speedroll technology, designed to create a rolling sensation, particularly beneficial for heel strikers. The EP3 gained popularity among this group, and undoubtedly, the 4th iteration will continue to serve heel strikers well.

Everything we've discovered about this shoe leads us to believe it's one of the most accommodating supershoes out there, and here's the ultimate evidence.

Unlike the overly snug and narrow uppers common among its rivals, the Endorphin Pro 4 boasts an impressive maximum width of 96.5 mm in the widest part.

Before conducting our second measurement, we thought: maybe the Pro 4 now has a sharper taper like the Speed 4, making it less roomy than it seemed...

But we discovered otherwise! At 72.5 mm in the big toe area, it has a standard taper for a running shoe yet feels impressively roomy for a competition-focused design.

To conclude our series of tests with the gel mould and wrap up the fit analysis, we award high marks to the Endorphin Pro 4 for toebox height. At 27.7 mm, it offers good vertical space for toe movement compared to all shoes, but it stands out as one of the most comfort-focused supershoes.

This, of course, might be seen as a drawback too. Many runners expect a snug, race-ready fit in a competition shoe, and this one doesn’t deliver that fierce, locked-in feel. It’s fast, agile, and secure, but its fit leans more toward comfort, making it a better choice for longer races than shorter ones.

We were genuinely pleased with the lab results of the Endorphin Pro 4. We tested the shoe in wet conditions and measured a 0.52 score—providing strong grip on slick surfaces and ultra-reliable traction on dry pavement.

That’s a better result than the pricier Endorphin Elite (0.42), making this racer a smarter option inside Saucony's supershoe lineup for those who value race-day grip.

Although the EP4 has some exposed foam, it offers more rubber coverage than the average supershoe. It’s one of those subtle nods from Saucony to attract casual runners—just like the slightly lower price compared to most high-end rivals.

We've already highlighted in this lab review that the Endorphin Pro 4 incorporates a carbon plate within its midsole, a feature synonymous with exceptional longitudinal stiffness.

Our 30-degree bend test yielded a 25.7N result for the Pro 4, a level of stiffness that's characteristic of shoes equipped with a rigid carbon-fibre plate. Consequently, some runners might find the shoe to stiff for easy runs.

Following another 20-minute chill session in the freezer, we conducted the stiffness test once more on the Pro 4, with impressive results. The shoe became only 9% stiffer, a testament to the remarkable performance of its Pebax-based foams!

One crucial aspect of running performance is the shoe's weight, and unfortunately, this is where the Endorphin Pro 4 falls short. Although it's still relatively light at 7.8 oz (220g), it's noticeably heavier than the 7.3-oz Endorphin Pro 3 and lags behind many competitors.

Ultimately, compromises are inevitable in running shoes. The added weight is a trade-off for enhanced durability and cushioning compared to its predecessor, which explains the increase. However, for runners prioritising raw performance over comfort, this might not be an appealing trade.

Breathability is a key factor for marathon shoes, as maintaining good airflow is essential to keep feet comfortable, preventing blisters and swelling during long races. Impressively, the Endorphin Pro 4 stands out in this aspect, achieving a flawless 5/5 score in our breathability smoke test, marking it as a top performer.

The upper of the Endorphin Pro 4 is remarkably thin, enhancing its breathability to an exceptional level. During our light test, it became evident that this shoe was among the elite few, showcasing a degree of transparency throughout its structure, not just limited to the toebox but extending across the entire upper, which truly impressed us.

Delving deeper with our microscope, we were keen to examine the engineered mesh upper more closely.

Our anticipation was met with the discovery of a high-quality mesh that's seldom seen in the industry. The attention to detail and the level of engineering invested in creating such a complex pattern of hexagonal shapes and strategically placed ventilation holes throughout the shoe confirmed our initial impressions.

In our manual assessment, we observed adequate padding in the heel area, which is fine for a shoe designed for race day performance.

However, we need to remember that the Endorphin Pro 4 is crafted with a clear focus on achieving personal bests, where comfort is not the main goal at all.

Right off the bat, we noticed a significant boost in stability with the Endorphin Pro 4 compared to its predecessor, thanks to an all-new geometry and the firmer foam.

We believe enhanced stability is a key feature distinguishing the Pro 4 from other supershoes, allowing for its use in easy and moderate runs if you're at ease with a carbon plate. In these scenarios, it essentially transforms into a supercharged daily trainer!

With the inclusion of a carbon plate, we anticipated a high result in this test, and the Endorphin Pro 4 did not disappoint, earning a solid 4/5 in our lab assessment.

We often award a 5/5 to carbon-plated shoes, highlighting that this model is slightly less focused on peak performance and more on offering a smoother, gentler ride as a supershoe.

The heel counter is exceptionally soft (1/5). Lacking any stiff components, the EP4 is a great choice for those prone to Achilles discomfort.

A significant update from the previous model is the wider midsole, notably in the forefoot area, where it now measures 118.9 mm, up from 109.3 mm.

This adjustment greatly impacts the shoe, enhancing stability and comfort, particularly for forefoot strikers. However, it also leads to an increase in weight, which is quite perceptible.

The heel, while still narrow, has been widened in the Pro 4 to 89.2 mm from the Pro 3's 86.0 mm. This enhancement further supports heel strikers, facilitating a smooth transition from heel to toe with Saucony's Speedroll technology.

Given the ultra-thin mesh of the Endorphin Pro 4, we were initially sceptical about its durability, especially since similar shoes often succumb quickly under our rigorous Dremel tests.

To our amazement in the lab, the Endorphin Pro 4 showcased exceptional durability, scoring an impressive 4/5 partially thanks to the branded TPU overlay. For those seeking a high-performance supershoe with a robust upper, this model stands out as an exceptional choice.

Turning our attention to the heel padding, we anticipated another standout performance—after all, momentum was on our side.

True to our expectations, the EP4 delivered an outstanding result, surpassing our previous assessments and achieving a perfect 5/5. This is particularly remarkable for a race-day shoe that manages to incorporate a notable amount of padding in the heel.

When we examined the outsole, our first step was to measure its hardness—a reliable indicator of what to expect. Our findings showed an 85.3 HC reading, not only surpassing most shoes but also proving to be significantly tougher than many competitors.

The grip was satisfactory, though not stellar, leading us to believe that Saucony aims to establish the Endorphin Pro 4 as an exceptionally durable supershoe, which seems to be its niche in the market.

To assess whether the high outsole hardness translates to durability, we fired up the Dremel once more, this time at a higher RPM.

Our test resulted in a mere 0.6-mm indentation, indicating impressive durability.

In our final step, we measured the outsole thickness and found a robust 2.1 mm of XT-900 rubber. This thickness suggests the Endorphin Pro 4 should easily withstand at least 300 miles of fast running.

While individual results may vary based on factors like footstrike, weight, and running surface, we're convinced that few supershoes can outlast this one in terms of durability.

We measured the insole of the Endorphin Pro at an impressive 6.1 mm thickness, which is quite substantial. But there's a good reason for this extra thickness.

Unlike the typical EVA used in 99% of insoles, Saucony has opted for what they call "Super Responsive Sockliner", made from supercritical foam. This material does more than just provide comfort—it also enhances cushioning and energy return.

Pebax foams are renowned for their stellar adaptability across multiple temperatures.

We subjected the EP4 to a cold stress test, putting it in the freezer for 20 minutes. The outcome was truly noteworthy—the foam's firmness increased by a mere 5.1%!

Unlike many racing shoes, the Endorphin Pro 4 features a removable insole, allowing for customization if necessary.

However, the insole's unique design, especially its ultra-narrow heel, is tailored for performance. And this insole is crafted from supercritical foam, enhancing the shoe's performance, an advantage you might forfeit by switching to a third-party option.

We didn't spot any reflective elements on the Endorphin Pro 4, but in our opinion, they're not essential for race-day shoes, so that's fine!

The tongue is exceptionally well-ventilated and notably thin. At 1.7 mm, it's almost twice as thick as the tongues of other supershoes, which often measure less than 1.0 mm—a feature those with sensitive insteps will surely value.

Our tests revealed that the tongue's thickness strikes a perfect balance for a comfy racing shoe. Given that the Endorphin Pro 4 is designed for high performance but still ranks below the Elite model, Saucony's decision to opt for a slightly thicker tongue seems logical.

A significant change from previous Endorphin Pros is the shift to an Alphafly-style, sock-like tongue, moving away from the semi-gusseted design that was standard in this series. Both styles offer effective lockdown, ultimately boiling down to personal preference.

Saucony has continued the trend of omitting heel tabs in their recent Endorphins, and the Pro 4 maintains this choice.