Adidas Adizero Prime X Strung vs Asics Superblast: Two High-Cushion Training Shoes Compared

Introduction

Both of these shoes promise something similar on paper: a huge amount of cushioning that still lets you run fast. That combination is exactly what many runners want for marathon training, tempo sessions, and long consistent efforts, so we put them through the same real-world testing to see where each one excels.

The comparison matters because these two shoes deliver that formula in very different ways. One leans on an extreme stack height and carbon-infused rods, the other on a blend of responsive foams and a wider, more stable base.

At a Glance: Specs and Pricing

The Adidas Adizero Prime X Strung costs £230 or $300, weighs 255 grams (9 oz) for men in a size 8, and has an 8.5 mm drop. The Asics Superblast comes in at £210 or $220, weighs 248 grams (8.8 oz) in the same size, with an 8 mm drop.

So on paper they are close: similar weight, similar drop, similar price. The differences show up in how each shoe feels on the run.

Adidas Adizero Prime X Strung: High Stack, High Thrill

The Prime X Strung is a super shoe designed to take learnings from Adidas’s popular racing range and apply them to faster-paced training. Its most noticeable feature, aside from the carbon NG rods, is the lofty 50 mm stack height of Lightstrike Pro midsole foam, built to offer a propulsive level of energy return. This version uses the Strung upper, created by mapping fibers on an individual thread basis for a comfortable, fitted feel, plus grippy Continental outsole rubber to handle different road conditions.

In practice, it is a lot of fun once you adapt to it. On flat routes it genuinely feels like the shoe is bouncing you along, and it makes longer training efforts feel easier. It also tends to make you run slightly faster without realizing it. The trade-off is stability. The thin heel section offers very little support, and when fatigue sets in on longer runs, the huge stack can feel wobbly, almost like being on stilts. It takes time to get used to, and the 50 mm stack height makes it a risky choice for serious racing or anything off a smooth, flat surface.

There is also a fit caveat: the heel design is quite pointed with minimal padding, and heel rubbing persisted over several test runs.

Asics Superblast: Bouncy, Stable, Tempo-Focused

The Superblast is a daily training shoe that veers toward faster and longer efforts. Its midsole combines FF Plus Plus, the same foam used in the Novablast 3 and Magic Speed 2, with FF Plus Turbo, the speed-focused cushioning used in the Metaspeed Sky Plus. The result aims to deliver a cushioned yet responsive ride across a range of sessions. It also features a thin asymmetrical mesh upper for breathability, a heel stabilizer for a secure ride, an AHAR Plus outsole for grip, and a trampoline-inspired outsole design for a more responsive bounce.

Where it shines is tempo work. The FF Turbo midsole is fairly firm rather than soft and squishy, and that firmness gives the shoe a nice pop that helps you hold a consistent pace over long distances. It feels natural underfoot without forcing your foot into a position, and the wider base inspires far more confidence than the Prime X Strung. On slower, easy runs it does not add much, but it never does anything wrong either; it simply skews toward faster, steady efforts.

Which One Should You Buy?

Surprisingly, these two shoes are not as similar as their specs suggest. The Prime X Strung is the faster, more propulsive option and handles both quick training runs and slower easy mileage, but the stability concern and the pointed heel make it a niche shoe that some runners simply will not get on with. The Superblast is not quite as fast, but it is more comfortable, more stable, and feels more natural, with a nice bit of bounce in the turnover.

Both fit true to size. If you are unsure which way to go, the Superblast is the safer all-round pick, especially for longer-distance race training where you want a reliable partner for tempo and consistent-pace efforts. The Prime X Strung suits runners who prioritize speed and fun on flat, familiar routes and are willing to adapt to its extreme design.

If neither sounds quite right, alternatives worth considering include the Saucony Endorphin Speed 3, which is more versatile and cheaper than both, and the Hoka Mach 5, a much lower-stack, natural-feeling option that still handles fast sessions and long runs well.

Conclusion

These are both enjoyable shoes for faster, consistent training efforts rather than true racing or short intervals. The Adidas Adizero Prime X Strung delivers a thrilling, bouncy ride if you can handle its towering stack and heel fit quirks, while the Asics Superblast offers a more stable, natural-feeling option that excels at tempo and long-run pace. At similar prices, the choice really comes down to how much stability you need and how adventurous you want to be.