Hoka Skyward X vs Adidas Adizero Prime X Strung 2: Which Max-Cushion Super Trainer Fits You?

Introduction

Max-cushion super trainers have become a real category, and two of the most interesting options right now are the Hoka Skyward X and the Adidas Adizero Prime X Strung 2. Both sit well above 40 mm of stack from heel to forefoot, both carry a lot of foam underfoot, and both weigh essentially the same in a men’s size 9 or women’s size 10.5 at 10.8 oz.

The similarities stop there. These two shoes have noticeably different rides, fits, and stability profiles, and choosing between them depends heavily on how you run and how your feet are shaped. Here is how they stack up.

Specs at a Glance

The Skyward X measures 49 mm in the heel and 44 mm in the forefoot for a 5 mm drop. The Prime X Strung 2 measures 50 mm in the heel and 43 mm in the forefoot for a 7 mm drop. Both come in unisex sizing with separate women’s versions available.

Both shoes are extremely tall, extremely cushioned, and among the most shoe you can put underfoot for a trainer. The differences show up in what that foam does when you start moving.

Midsole Construction

The Skyward X uses a central layer of PEBA foam running the length of the shoe, wrapped in an EVA frame around the outside, with a carbon fiber plate in the mix. The exact formulation of the Hoka foam is not publicly detailed, but it is a foam that moves quickly for its thickness.

The Prime X Strung 2 takes a different approach: multiple full-length layers of Lightstrike Pro stacked through the midsole, with both a plate and rods adding structure. The result is a very stiff platform underfoot, though the rocker softens that impression until you pick up the pace.

Ride and Performance

The Skyward X is the softer of the two. Step into it and the first impression is cushioning: a tall, plush, relaxed ride that rolls smoothly and suits easy days and long runs. It handled a workout fine, but it is clearly not the fastest option in this pairing. Think training miles, long runs, and maybe light uptempo work.

The Prime X Strung 2 is the faster of the two. It can handle training miles comfortably, but it really shines at marathon pace and faster: uptempo workouts, quicker long runs, and any effort where the firmer Lightstrike Pro and snappier ride pay off. Both shoes have strong rocker geometry; the Skyward X rolls more smoothly at relaxed paces, while the Prime X Strung 2 feels more propulsive.

If you want maximum cushioning for a marathon, either could work. For anything shorter than that, neither is the right tool. The Skyward X leans toward road ultras and long slow days; the Prime X Strung 2 makes sense as a maximally cushioned marathon option.

Fit and Upper

Fit is where these two diverge the most. The Prime X Strung 2’s strung upper has a noticeably higher volume fit: plenty of width and some stretch in the material, though laces need to be cranked down to feel secure. If your feet are normal to wide, or high-volume in general, this is the better match.

The Skyward X follows classic Hoka fit cues. The forefoot widens where the Hoka lasts do, but the toe box is a little tapered and the knit upper sits low, creating a much lower-volume fit with a highly cushioned feel. Normal to narrower feet will likely feel at home here.

Neither shoe is conventional at the heel. The Prime X Strung 2 has no heel counter at all, which is great if you are sensitive to them. The Skyward X has a heel counter but buries it under so much padding that it is easy to miss, though very sensitive runners should take note.

Stability

These could not be more different when it comes to stability. The Skyward X is a stable neutral shoe: a wide base, a filled-in midfoot, and tall sidewalls on both sides that are easy to notice. If you like sidewalls, this shoe does the job well; if you are sensitive to them, be aware. The EVA frame wrapping the PEBA foam adds a centered, non-biased stabilizing effect.

The Prime X Strung 2 is laterally biased. There are mild sidewalls in the forefoot, the forefoot is wider than most, and the posterior lateral heel bevel shapes the shoe so you land with more material on the medial side, almost like a built-in medial wedge. That works well for runners who need medial support, but it is a poor match for anyone with excessive lateral motion. This is not a centered, neutral ride.

Durability

The Prime X Strung 2 deserves a shout-out here: after more than 100 miles, the outsole shows virtually no wear. It is a tank.

The Skyward X has fewer miles on it so far, with a tiny bit of abrasion visible early on, but nothing that suggests it will not also hold up well over a full lifespan. Both look like shoes you can get serious mileage out of, with the edge going to the Adidas based on the track record so far.

Which One Should You Buy?

Choose the Hoka Skyward X if you want the softer, more relaxed ride, a lower-volume upper for normal to narrower feet, and a stable neutral platform for long miles and road ultras. Choose the Adidas Adizero Prime X Strung 2 if you want something snappier for marathon-pace work, a higher-volume fit, no heel counter, and a laterally biased ride that suits runners who need a bit of medial support.

Both are excellent examples of what max-cushion super trainers can be; the right pick comes down to your feet and your pace.

Conclusion

The Skyward X and Prime X Strung 2 share nearly identical specs but serve different runners. Softer and stable neutral versus snappy and laterally biased, low-volume versus high-volume. Match the shoe to your feet and your goals, and either one can become a genuinely useful addition to the rotation.