Adidas Adizero Prime X Strung Long Run Review: Does Max Cushion Hold Up Over Distance?

Introduction

The Adidas Adizero Prime X Strung sits at the maximalist end of the midsole cushion spectrum, and the big question for this test was simple: does it hold up on genuinely long runs as well as the previous versions of the Prime X did? To find out, this review is built around a 20km long run at a steady tempo pace rather than a short-effort first impression.

The Long Run Test

The test route covered roughly 12 miles around town edges: about eight miles of consistent uphill followed by four mostly flat, downhill miles, in crisp but mild morning temperatures with little to no wind. Pace averaged around 7:45 per mile over about 1 hour 33 of running, with heart rate kept comfortably in the aerobic zone for nearly the entire effort.

That last point matters for this shoe. The Prime X Strung rewards controlled, assured running, and the run felt almost too easy as a result, finishing noticeably faster than planned at a lower heart rate. Part of that comes down to pacing discipline in the opening miles, which is exactly the kind of running this shoe seems designed around.

Upper: Strung Material, Lockdown, and Comfort

The Strung upper is thicker to the touch than the one on the original Prime X, yet a little more flexible. In mild temperatures around 8°C (47°F) it performed well, and paired with thicker padded running socks there was no rubbing or blister formation over the full distance. Lockdown with a runner’s knot was excellent, with no lace tension problems or pressure points across the top of the foot.

A genuine highlight: the Strung upper does not pick up grime and grit the way typical mesh uppers do. A quick wipe with a cloth keeps it looking fresh, where fabric-based uppers often grab debris and discolor quickly. Some runners have reported heel problems with this upper, but in this test no such issues appeared at all over the long run distance.

Midsole: Lightstrike Pro and Break-In Behavior

The midsole combines Lightstrike Pro with Adidas’s zMAX setup, and the standout finding is how the foam changes with miles. Around 42 miles in, the segmented foam keeps feeling better underfoot with every run: more flexible, more energetic in its return, and less uncontrolled in the bounce. This break-in behavior matches what has been seen in other Adizero models, and the legs felt genuinely fresh the day after the long run, with no aches or soreness.

The shoe also encourages a midfoot landing to engage the carbon blades, and stronger ankles clearly help you get the most from it. The more containing Strung upper locks the foot down onto the midsole base more effectively than the first Prime X version, and any perceived midsole differences between versions seem to come from that upper change rather than the foam itself.

Outsole: Continental Rubber Grip

Outsole grip was one of the bigger surprises of the test. The Continental Rubber outsole felt reassuring across grassy sections and scattered debris, and it is a genuinely versatile road and pavement shoe in dry and damp conditions.

There are clear limits though. It is not designed for trails, and stony paths or cobblestones are best avoided entirely. Among current shoes, Continental Rubber and Puma’s Fast-R Nitro Elite sit at the top of the outsole class, particularly for wet-surface confidence.

Things to Consider Before Buying

This is not a beginner’s shoe. It demands a very assured foot strike, and heavier runners should probably avoid it because the midsole foam cut-outs in the arch area can collapse inwards under load. It works best for lighter runners logging significant weekly mileage, and if the Adizero Pro 2 worked for you, the Prime X Strung is very likely to hit the mark too.

The price is also high enough that buying it as a gamble is a bad idea. If it does not suit your stride, it can genuinely cause problems, so treat it as a specialized long-run tempo shoe rather than an everyday default.

Conclusion

The Adidas Adizero Prime X Strung passed the long run test convincingly: superb upper comfort and lockdown, a Lightstrike Pro and zMAX midsole that keeps improving with break-in, and stronger-than-expected grip from the Continental Rubber outsole. It is a rewarding shoe for lighter, experienced runners who land midfoot and want maximal cushioning for long tempo efforts, but the demanding ride, arch instability for heavier runners, and high price mean it is not for everyone. If the profile fits, it is a very easy shoe to recommend.