The adidas Adizero Prime X3 STRUNG is a maximalist super trainer that stacks almost 50 mm of Lightstrike Pro foam over a full-length carbon plate and carbon Energy Rods to deliver a stiff but dynamic ride for long road efforts. It pulls the Prime X back toward the wild, rule-breaking feel of the original iteration. It has a soft heel, but balances that with a very wide forefoot platform that keeps uptempo efforts feeling surprisingly controlled for such a tall shoe. A late, aggressive rocker encourages you onto your toes when you push the pace, so it feels most at home on steady long runs where you can load the forefoot and let the geometry work to your advantage. At slower recovery paces, the geometry and double-plate stiffness make it feel awkward and bulky compared with simpler super trainers, and lighter super shoes feel a lot more adapted and nimble for actual racing and very fast paces. Still, if you want adidas's most over-the-top, super-cushioned shoe for uptempo long runs, this is a cool shoe to add to your arsenal.
Our Verdict
The adidas Adizero Prime X3 STRUNG is a super trainer that's built for long, steady efforts rather than optimized for racing. Its towering stack, very soft heel, and wide forefoot platform give you a highly cushioned, energetic ride that makes it easy to lock into marathon pace and stay there, especially if you can quickly roll through the rocker or if you naturally land toward the forefoot. Also, the plate and carbon rods make the shoe quite heavy and bulky. Overall, it's not very stable, which can make tight turns and uneven roads a bit uneasy. For top marathon performance, there are lighter super shoes that feel more adapted if you are chasing a strong performance, so this model primarily suits runners who value comfort and fun bounce over more streamlined options designed for pure racing efficiency.
Huge stack provides exceptional impact protection for long runs and high-mileage training blocks.
Very energetic midsole compound, especially under the forefoot.
Carbon plate and Energy Rods combo add stiffness and structure to the ride.
Quite heavy and bulky, which impairs overall efficiency.
The adidas Adizero Prime X3 STRUNG doesn't really feel at home in 5K and 10K races, where its height and weight tend to work against the need for quick, snappy transitions. The forefoot is cushioned and very energetic, which helps, but the toe off isn't very crisp. Combined with the heavy platform, that means it won't feel as agile or responsive as lightweight super shoes in technical courses or in scenarios where multiple surges are required. It can still be a viable option for short races, but most runners chasing a personal best over these distances will find more suitable options in lighter, snappier plated racers.
Very energetic midsole compound, especially under the forefoot.
Carbon plate and Energy Rods combo add stiffness and structure to the ride.
Forefoot isn't very firm.
Quite heavy and bulky, which impairs overall efficiency.
The adidas Adizero Prime X3 STRUNG delivers amazing energy return, with both the heel and forefoot rebounding very well. Under the forefoot, the thick chunk of Lightstrike Pro foam sandwiched between the plate and the rods bounces back especially well under load, so each stride feels springy when you pick up the pace. If you can hit that forefoot sweet spot, your long tempo runs and progression runs will feel very dynamic, helping you maintain speed with a bit less perceived effort.
Very energetic midsole compound, especially under the forefoot.
The adidas Adizero Prime X3 STRUNG offers outstanding cushioning, providing a very protective landing under both the heel and the forefoot. The huge slab of foam absorbs hard impacts on long road runs and helps keep your joints and muscles from feeling beaten up when pushing through big mileage weeks or back-to-back sessions. Despite the very protective midsole, the ride doesn't feel overly mushy either, since the plate and rods add some structure that limits the sink and stall feel traditionally present with super-cushioned shoes. That said, the extreme stack height creates a tall, somewhat disconnected feeling from the ground, especially at easy paces,
Huge stack provides exceptional impact protection for long runs and high-mileage training blocks.
The adidas Adizero Prime X3 STRUNG doesn't have the best lateral stability. Up front, the broad outsole and stiff plate-rod combo help keep the shoe planted when you are running straight ahead at faster paces, so it feels relatively secure once you're up on the rocker. Toward the heel and midfoot, however, the high center of gravity and compliant foam add some instability, particularly for heel strikers or runners whose form tend to break down over time.
Wide forefoot.
Carbon plate and Energy Rods combo add stiffness and structure to the ride.
Very soft foam.
Very tall stack height.
Performance Usages
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Differences Between Sizes And Variants
We bought and tested the adidas Adizero Prime X3 STRUNG in a men's US size 9, as noted on the label for our pair. The pair we purchased is the Flash Aqua/Zero Metallic/Lucid Lemon colorway, but you can also get the shoe in several other colorways, including Cloud White/Core Black/Lucid Red, Powder Plum/Aurora Black/Shock Pink, and Lucid Lemon/Core Black/Halo Silver, depending on the region. Both the men's and women's versions are only available in a standard width, with no dedicated narrow or wide options. The design section applies only to the exact model we tested, but we expect other size and gender variants to perform similarly.
Popular Running Shoe Comparisons
The adidas Adizero Prime X3 Strung is a super-max super trainer built for long runs and marathon-pace workouts, best suited for runners who want huge cushioning, high rebound, and a stiff, rockered platform that feels lively once you're rolling; it's not ideal if you need nimbleness, low weight for racing, or stable cornering at slower paces. It feels especially lively under mid- to forefoot strikers, while heel strikers still enjoy strong energy return and excellent softness, though they might not experience quite the same magic bounce. If you want a long-distance alternative with more composure and easier turnover with a more traditional geometry, check out the HOKA Mach X 3. If you want an unplated max cushion that still picks up the pace, the ASICS SUPERBLAST 2 is lighter and more adaptable across efforts.
Within adidas's Adizero lineup, choose the adidas Adizero Adios Pro 4 or the adidas Adizero Pro Evo 2 for race-day efficiency and lower weight compared to the Prime X3. The adidas Adizero Takumi Sen 11 remains the brand’s low-stack option for short, fast sessions, while the adidas Adizero Boston 13 serves as a firmer, more traditional-feeling super trainer. Both models deliver a far more grounded, classic ride than the towering Prime X 3. There's also the adidas Adizero Evo SL, a versatile unplated uptempo trainer. Still, the Prime X 3 can have its place in your rotation for steady long runs, especially if you prioritize maximal cushioning and rebound, and you're comfortable with its towering stack and plate-rods setup.
If you're looking for more options, check out our recommendations for the best running shoes, the best long-distance running shoes, and the best shoes for running a marathon.
The adidas Adizero Prime X3 STRUNG and the Adizero Prime X 2.0 STRUNG share the same concept of a double carbon system with a plate and Energy Rods, but the third version refines it into a taller, softer, and more protective package. The Prime X3 adds even more cushioning, with a thicker slab of foam between the plate and rods under the forefoot, giving a smoother, more forgiving ride underfoot. On the other hand, the Prime X 2.0 is slightly more performance-oriented in its geometry, with a flatter midsole that makes it feel more stable, especially around the arch, with a smoother transition. The arched outsole geometry and higher heel of the Prime X3 also create a more aggressive geometry, which also makes it less stable.
The adidas Adizero Prime X3 Strung and the adidas Adizero Adios Pro 4 may share a family name and a big chunk of Lightstrike Pro foam, but they're built for very different purposes. The Prime X3 is a super trainer: heavier, much higher stacked, and far more cushioned, with a dual propulsion system that delivers huge rebound but feels too bulky to race efficiently. The Adios Pro 4 is the true super shoe in the lineup: lighter, snappier, and more energetic thanks to its carbon Energy Rods and firmer, more responsive forefoot. The Prime X3 offers more protection and long-run comfort, making it ideal for marathon-pace training blocks, while the Adios Pro 4 provides better efficiency, quicker turnover, and a more race-ready feel for half marathons and full marathons.
The HOKA Mach X 3 and the adidas Adizero Prime X3 STRUNG are both super trainers, but they sit at very different ends of the category. The Mach X 3 is noticeably lighter and uses a more traditional setup built around a single plastic plate and a dual-foam midsole, giving it a familiar rocker and a stable, approachable ride. It feels like an enhanced daily trainer that adds just enough propulsion for uptempo work while keeping its geometry smooth and predictable at most other paces. The Prime X3, by contrast, is far more extreme: it has a much higher stack, a double-decker propulsion system with a carbon plate plus Energy Rods, and significantly more bounce and cushioning underfoot. It delivers stronger energy return and a more dramatic rolling sensation at marathon effort, but it's also much stiffer, bulkier, and less forgiving at easy paces.
We've recently started buying and testing running shoes with a very data-oriented approach. While we're just getting started, our methodology already has dozens of tests to help you make the right purchasing decision for your needs. Not only do we use high-end equipment to gather objective data, but we also order multiple sizes of the same shoes for team members to be able to log in miles. This real-world testing is done at various paces and conditions, and with different types of workouts, to cover all the bases. This allows us to verify our results and ensure they align with what you might feel with a specific pair.
Test Results
The adidas Adizero Prime X3 STRUNG is a heavy shoe, especially for a performance-oriented model. On foot, that weight is most noticeable when you're accelerating, where the platform feels slow to turn over compared with leaner options.
This shoe has an extreme stack height that pushes even higher than the previous adidas Adizero Prime X 2.0 STRUNG. This towering midsole creates a very cushioned, hovering sensation with a lot of space between your foot and the ground, which is great for impact protection but clearly prioritizes protection over ground feel and stability.
This iteration has a different sole geometry than the adidas Adizero Prime X 2.0 STRUNG, and that change can be felt underfoot. The second version uses a flatter sole, whereas the third version has a midsole and outsole that dip more aggressively at the arch and a heel that rises, which saves some weight but is also a bit less stable, especially for heel strikers.
The adidas Adizero Prime X3 STRUNG features a full-length carbon plate under the foot and carbon-infused ENERGYRODS 2.0 embedded lower in the midsole, giving it two stiffening elements working in concert. This layout adds rigidity to the forefoot and stabilizes the chaotic Lightstrike Pro compound, but it doesn't make the shoe feel particularly propulsive.
The adidas Adizero Prime X3 STRUNG features great heel energy return, with the Lightstrike Pro foam under the rearfoot rebounding quickly after compression. On the road, this translates into lively landings for runners who touch down toward the heel, as the midsole decompresses rapidly to help roll you forward into the midfoot without feeling dead.
This shoe delivers very impressive forefoot energy return, indicating that this part of the shoe is the main engine of its very energetic feel. With a thick layer of Lightstrike Pro sitting between the plate and ENERGYRODS, each stride loads the forefoot and snaps back as you push off, especially once you are settled into uptempo or marathon pace. This makes the shoe feel very playful when you're up on your toes, rewarding runners who can drive powerfully through the front of the midsole.
The adidas Adizero Prime X3 STRUNG offers exceptional heel cushioning across a range of loads. Landings feel very protective, which helps reduce pounding on the knees and hips for both lighter and heavier runners who run at a variety of paces.
The adidas Adizero Prime X3 STRUNG also provides fantastic forefoot cushioning, with high impact absorption at the front of the shoe, and on the run, this translates into a comfortable platform that's especially well-suited for long progression runs and marathon pace efforts where repetitive loading can otherwise make the forefoot feel beaten up. That said, the stiff plate-and-rod combo keeps the foam from feeling too mushy, so you don't get an excessive sink-in sensation.
The adidas Adizero Prime X3 STRUNG has a very soft heel, giving heel landings a plush, forgiving feel that many runners will appreciate. However, that same softness combined with the tall stack height makes the heel of the shoe feel more wobbly on uneven surfaces or when you corner aggressively, so it favors runners who value plushness over stability.
The forefoot feels noticeably firmer than the heel, especially in the mid-force range where most runners naturally fall into, and the carbon plate and ENERGYRODS are a big reason why. You still get enough give and plushness to keep things comfy, but the overall sensation isn't overly soft either.
The adidas Adizero Prime X3 STRUNG offers excellent forefoot cushioning that holds up impressively well over long distances. The shoe starts off highly protective and only loses a small amount of impact absorption by the time we simulate a full 50K run, so you still get a very cushioned feel under the forefoot, even deep into a long run.