Hoka Skyward X review

We've rigorously tested the Skyward X in our lab and confidently recommend it for:

• Bondi 8 and Bondi X enthusiasts seeking even greater cushioning and energy return—this supertrainer features PEBA and steps up the game!
• Runners in search of a carbon-plated, max-cushioned shoe that combines durability with top-tier performance.
• Marathoners looking for a premium long-run shoe that also works well at recovery runs if needed.

The Skyward X might be a real supertrainer, but it's a heavy one. We think if you're looking for a lighter max-stack shoe, you should check out the ASICS Superblast 2 or the ASICS Magic Speed 4. Both of these are much lighter and work better for fast running.

We've also observed that this shoe is too narrow for many runners, including those with normal-sized feet who prefer a roomier fit. If you're looking for more space, the On Cloudmonster Hyper provides ample room in the toebox. And inside the Hoka lineup, the Mach X is super responsive and offers a slightly wider fit than the Skyward X, as we proved in the lab.

The Skyward X easily ranks in the top three most impressive unboxings due to its massive size. Now, let's delve into some specific measurements.

The dark protrusion nestled between the two foam layers is the winged carbon plate, designed to enhance stability.

Starting with the heel stack, the Skyward X categorically places itself among supertrainers with a towering 46.3 mm stack height—a dream come true for heavyweight heel strikers seeking world-class impact absorption.

The Skyward X not only features an impressive 37.1 mm of cushioning in the forefoot—surpassing nearly every heel cushioning we've measured in the lab—but it also makes an excellent choice for marathoners.

These enthusiasts of the Sunday long run, often covering distances exceeding even 20 miles, will find that the extensive cushioning of the Skyward X preserves their muscles, offering a notable advantage over less cushioned options for high-mileage training.

After evaluating the heel and forefoot stacks, our measurements revealed a 9.2 mm drop—good for most running styles and particularly beneficial for heel strikers seeking long-distance comfort.

Interestingly, Hoka claims a 5 mm drop, a huge discrepancy with our findings. For anyone wondering about these discrepancies, we're ready to provide clear explanations!

The Skyward X from Hoka captures attention with its colossal midsole—let's dive into the details.

This model features a dual-foam configuration, which is the norm in supertrainers. The top layer is crafted from premium PEBA—as expected in any shoe priced over £200—offering excellent energy return, similar to top-tier models like the Hoka Rocket X 2.

We tested the softness of the PEBA layer with our durometer and recorded a measurement of 19.8 HA. It doesn't feel like walking on clouds by any means, avoiding the overly plush feel that can undermine stability in such a tall shoe.

The lower layer of the Skyward X's midsole is crafted from supercritical EVA, not PEBA, aligning with the foam used in Hoka's recent training shoes. This layer is softer than the other, enhancing comfort with each step due to its significant compression. Yet of course, with over 40 mm of stack height, expect no ground feel in the Skyward X.

Why not use a full-PEBA midsole like in the Cielo X1? We think there are several reasons. Incorporating a softer EVA base enhances durability by shielding the more delicate PEBA from direct ground impact, and significantly cuts manufacturing costs since EVA is much less expensive than PEBA.

Nonetheless, at £220, the use of EVA is in the limit. To put it in perspective, the Saucony Endorphin Pro 4 offers a full-length carbon plate and a 100% PEBA-based midsole for the same price.

We placed the Skyward X in a freezer for 20 minutes to assess how the foam would behave under cold conditions. Impressively, the softness of the foam only decreased by a minimal 1.3%. This outcome was so outstanding that it was almost hard to believe!

The insole is standard, identical to what Hoka uses in many other models, with a typical thickness of 4.2 mm.

Hoka introduces a significant innovation in the Skyward X—not just inserting any ordinary carbon plate but crafting an all-new, H-shaped design. This innovation aims to provide the dual benefits of carbon plate snappiness and added flexibility for more relaxed paces.

Yet, we question whether a carbon plate is necessary in a training shoe, especially considering the cost increase it brings to the consumer. While nylon-plated shoes like the Endorphin Speed 4 manage easy paces without excessive stiffness, the Skyward X caters only to those who prefer the stiff feel of carbon in a training context.

The Skyward X stands out as one of the most rockered shoes we've tested in our lab, featuring a pronounced continuous curve that's clearly visible in our video below. This curvature is crucial, particularly given the shoe's colossal stack height and stiffness, ensuring smooth transitions.

For those interested in exploring more about rockered running shoes, we offer a detailed guide that covers everything you need to know.

We conducted our second measurement in the toebox around the big toe area, where it measures a reasonable 77.0 mm—slightly wider than expected.

This width makes the shoe suitable for those with average-sized feet. However, it's crucial to note again that this model doesn't offer much volume. Instead, it opts for a snugger fit, which may not suit everyone.

We always start by testing every shoe on our feet before measuring. Right away, the Skyward X felt narrow, a feeling we later quantified with a measurement of 95.6 mm across the widest part of the upper.

For those familiar with this brand, the classic Hoka-esque performance fit won't come as a surprise—most times it features a low volume in the toebox. And in the Skyward X, there's also a robust toe guard that enhances durability, but restricts the upper's stretchiness in that area despite the knit construction.

We conducted our second measurement in the toebox around the big toe area, where it measures a reasonable 77.0 mm—slightly wider than expected.

This width makes the shoe suitable for those with average-sized feet. However, it's crucial to note again that this model doesn't offer much volume. Instead, it opts for a snugger fit, which may not suit everyone.

Although the Skyward X stands as one of the tallest shoes we've evaluated in our lab, its stability is impressive for several reasons: the convex carbon plate, the ultra-stiff heel counter, substantial overall dimensions, and broad sidewalls contribute to its secure feel.

Is it the ideal choice for runners with stability needs? Perhaps not—we believe it doesn't quite fit that category. However, for neutral runners seeking a cushioned shoe that provides a sense of security during their runs, the Skyward X certainly stands out, despite some compromises.

We anticipated that the H-shaped carbon plate in the Skyward X might add some flexibility, but this simply wasn't the case. The substantial stack height combined with the natural stiffness of carbon fibre resulted in a shoe that is exceptionally rigid, unable to bend or twist. Consequently, it scored a well-deserved 5/5.

Running shoes typically feature a single heel counter, often a flexible piece of cardboard that goes inside the upper. However, in a bid for enhanced stability, the Skyward X incorporates two heel counters—one internal and one external—adopting a design usually reserved for stability shoes. Given its substantial stack height, this approach may seem justified for some.

On the downside, such a rigid setup might pose issues for runners with sensitive heels, such as those suffering from Haglund's deformity.

If we compared this shoe to a vehicle, it would undoubtedly be a massive SUV—think Cadillac Escalade or Hummer. That's the level of bulk we're talking about here, a fact confirmed by our measurements.

In our lab tests, we recorded a staggering 123.7 mm in the forefoot, a size almost unheard of in the lab, even for stability shoes. Nonetheless, this immense dimension contributes significantly to the supportive feel during runs, yet it also brings the typical drawbacks of a larger, clunkier shoe.

The heel of this running shoe is notably broader even than many stability shoes, clocking in at an impressive 100.1 mm.

Such a generous width provides an expansive landing area for heel strikers, firmly establishing the Skyward X as one of the top supertrainers for heel strikers in our assessment.

A carbon-fibre plate paired with a thick midsole typically leads to significant stiffness—basic running 101. Naturally, we rigorously tested this claim.

In our bend test—where we flex the shoe up to 90 degrees from a fixed position—we needed to apply 54.2N of force, aligning perfectly with our expectations. Consequently, brace for a notably stiff ride and set aside any thoughts of using this shoe for casual walking or gym workouts.

After a second 20-minute session in the freezer, we repeated the test and observed a comparable result: 55.5N. With a minimal increase of just 2.5%, the Skyward X meets our expectations for a PEBA-based midsole, which typically exhibits good behaviour against temperature fluctuations.

It's unmistakably true that the Skyward X is both wide and tall, yet it's equally clear that Hoka hasn't prioritised reducing its weight.

At 11.1 oz or 315g, its heft was noticeable on every run, whether we were going slow or fast.

So, the real question is—does weight matter to you? If so, the Skyward X might not meet your expectations, especially if you want a supertrainer for faster paces. However, if you're open to sacrificing some lightness for exceptional cushioning and comfort, this could very well be the maximalist giant you've been waiting for.

Initially, we were quite sceptical about the flat knit upper of the Skyward X—typically, they underperform in our breathability tests, particularly when compared to engineered mesh uppers. But, surprisingly, this one excelled and got a 5/5.

During our smoke test, we discovered that the Skyward X boasts exceptional ventilation, making it well-suited for runs even during the hottest months of the year.

We used a light to closely examine how Hoka structured the upper for both ventilation and support. We observed that the toebox is remarkably thin, extending to the midfoot before it thickens, enhancing lateral stability.

Further investigations using a microscope allowed us to pinpoint the precise placement of ventilation holes across the entire toebox.

This detailed approach underscores the importance of conducting multiple tests to assess breathability—if we had relied solely on the microscope, we might have concluded that air flow could be restricted.

Overall, the upper is impressively crafted, offering the quality and performance you'd expect from a premium-priced shoe.

At a price tag of £220, we're not just expecting good ventilation—we're looking for durability as well. While there have been instances where Hoka's durability might have been underwhelming like the Mach 6, this time it seems they've taken those lessons to heart.

In our toebox durability test, the Skyward X delivered impressively, earning a robust 4/5 rating. This is particularly notable for a soft knit upper, which typically challenges durability standards. We also want to highlight that the toe cap includes multiple TPU overlays, enhancing protection in gravel roads or easy trails.

And wait until you hear about our heel padding challenge.

We put the shoe through our standard Dremel test—running it at 5K revolutions per minute with 3.2N of force. The outcome was phenomenal, as it earned a rare perfect score of 5 out of 5 in our lab.

We've really put the upper through its paces to gauge its durability and performance—yet, there's more to this shoe than just a robust knit. Now, we turn our attention to the outsole, crucial for justifying its sky-high price.

We applied our durometer to the high-abrasion rubber and discovered that Hoka opted for a remarkably soft compound, registering just 71.8 HC. This choice clearly aims to boost grip, enhancing the shoe’s performance on various surfaces.

Initially, we had our doubts about the durability due to the soft rubber formulation—however, it's best to reserve judgement until after we finish our testing.

We ramped up our Dremel to 10K RPM for a demanding durability test in our lab. The outcome was good—a mere 0.8-mm indentation solidly confirmed that this high-abrasion rubber not only provides exceptional all-weather grip but also stands up well to wear and tear.

To conclude our examination of the outsole, we measured a thickness of 3.1 mm—sufficient according to our previous tests. However, we believe Hoka could reduce this slightly to lighten the shoe. You'll soon understand why.

Spending £220 on the Skyward X does not get you reflective elements—a feature we've come to expect from Hoka in recent years.

The tongue boasts a substantial 9.5 mm of comfy foam padding—a bit excessive in our view.

We believe a slimmer 4 or 5 mm thickness would suffice, providing ample comfort within the performance-fit upper while also reducing the shoe's overall weight.

While the snug fit of the upper prevents the tongue from shifting, we find the absence of a gusseted tongue in a £220 shoe disappointing and believe it should be addressed in the next update.

True to Hoka's roots, the heel of the Skyward X skips the traditional finger-loop tab and instead features the iconic swallowtail extended heel collar. We found this design not only easy to grab but also effective in reducing pressure on the Achilles tendon.

We easily removed the insole of the Skyward X and experimented with various third-party insoles and even some custom orthotics. However, we discovered that thinner options are essential, as the internal space of the shoe is limited.