Our verdict

The Diadora Atomo Star is a retro-inspired maximalist trainer built for runners with deep pockets and a taste for exclusivity. We were impressed by its premium-quality materials and "Made in Italy" craftsmanship, which felt outstanding. However, we found in the lab that its extremely narrow fit and lack of a truly bouncy foam make the premium price harder to justify.

Pros

  • Plush foam
  • Fantastic shock absorption
  • Grippy and long-lasting outsole
  • Stable platform for heel strikers
  • Premium build quality
  • Excels on long runs
  • Amazing step-in feel
  • Extremely comfortable
  • Extremely comfortable

Cons

  • Snug, low-volume toebox
  • Lacks energy return
  • High price
  • Not ideal for faster paces

Audience verdict

N/A
Not enough reviews yet

Who should buy

The Diadora Atomo Star could be the next shoe for:

  • Runners looking to break away from mainstream brands while still enjoying premium-quality materials and a head-turning design.
  • Those who want a maximalist daily trainer with outstanding shock absorption and aren’t concerned about energy return.
  • Anyone seeking a retro-inspired running shoe that’s equally at home on a demanding long run and stylish enough to pair with jeans.

Diadora Atomo Star

Who should NOT buy

We believe the Atomo Star’s most limiting factor is its narrow, snug-fitting upper, which we found in the lab to be among the tightest we’ve measured. Runners who enjoy a roomy fit will likely find it restrictive. Options like the Adidas Ultraboost 5 or the Topo Atmos deliver a more spacious, comfort-driven feel.

From our perspective, the premium price could be too steep for many. While the “Made in Italy” label adds prestige and quality, we think many runners will see better value in the ASICS Novablast 5, which offers similar max-stack comfort at a much lower price.

Diadora Atomo Star parts

Lastly, we found the Atomo Star’s energy return underwhelming for its category, lacking the propulsive feel of premium foams. If responsiveness matters to you, the Adidas Adizero EVO SL delivers top energy return at a very good price.

Cushioning

Shock absorption

New

A quick look at the Atomo Star makes it obvious that it’s an extremely cushioned shoe, but we went further and ran it through our ASTM F1976 testing to see exactly how it stacks up against the rest of the market.

This Italian-made beauty turned out to be a true mattress for your feet, delivering outstanding results with 149 SA in the heel and 125 SA in the forefoot. Both numbers rank among the top we’ve measured, ensuring excellent impact protection and consistent shock absorption from heel to toe.

Diadora Atomo Star Shock absorption heel
Heel
Forefoot
Test results
Atomo Star 149 SA
Average 128 SA
Compared to 243 running shoes
Number of shoes
52 SA
Shock absorption
170 SA

Energy return

New

The Atomo Star sits on the higher end of the price range, but its energy return doesn’t match that level. We measured just 53.9% in the heel and 57.4% in the forefoot, which feels underwhelming.

This isn’t surprising at all. As we explained in our guide about energy return, lab testing has shown that supercritical EVA foams like ANIMA N2 can be cloud-soft and lightweight, but they’ll never deliver the same bounce as PEBA or A-TPU foams like ZoomX or Nitro Elite.

Heel
Forefoot
Test results
Atomo Star 53.9%
Average 58.3%
Compared to 240 running shoes
Number of shoes
38.0%
Energy return
82.0%

Heel stack

It’s no secret that the Atomo Star is a maximalist running shoe, that’s clear at first glance. Diadora really aimed to create a competitive trainer in this modern high-stack category that emerged just a few years ago.

We measured 39.9 mm of stack height in the heel, comfortably above the average running shoe and just 0.1 mm shy of the World Athletics race-day limit. Nonetheless, this detail doesn’t really matter here, as it’s not built for racing. Instead, it’s a training-focused shoe that can handle the occasional workout when needed, but nothing beyond that.

Diadora Atomo Star Heel stack
Test results
Atomo Star 39.9 mm
Average 34.4 mm
Compared to 435 running shoes
Number of shoes
22.5 mm
Heel stack
48.1 mm

Forefoot stack

The heel packs a serious amount of foam, measuring 32.1 mm in our digital calipers. This makes it ideal for forefoot and midfoot strikers seeking an ultra-cushioned shoe that provides lasting protection for runs beyond two hours... provided they’re not chasing top-tier energy return.

Diadora Atomo Star Forefoot stack
Test results
Atomo Star 32.1 mm
Average 25.8 mm
Compared to 435 running shoes
Number of shoes
13.7 mm
Forefoot stack
37.5 mm

Drop

In our lab, we place high importance on accurate heel-to-toe drop measurements, as discrepancies from brands can confuse runners.

The Diadora Atomo Star is advertised with a 6 mm drop, but our precise measurements showed a slight difference, coming in at 7.8 mm. This minor 1.8 mm variation is nothing concerning and likely unnoticeable for most runners.

Diadora Atomo Star Drop
Test results
Atomo Star 7.8 mm
Average 8.6 mm
Compared to 435 running shoes
Number of shoes
-0.2 mm
Drop
16.1 mm

Midsole softness

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

Those chasing a plush-and-cushioned ride will find it in the Atomo Star, as the EVA-based Anima N2 foam compresses easily at any pace, delivering a smooth feel whether jogging slowly or moving at a quicker rhythm.

We tested its softness with the Shore A durometer, recording 14.0 HA, which matches our on-foot impressions and confirms that it feels softer than the average daily trainer. This softness, combined with its excellent shock absorption, makes it a great choice for recovery runs the day after a tough workout.

Diadora Atomo Star Midsole softness
Test results
Atomo Star 14.0 HA
Average 20.7 HA
We use an average of four tests. The photo shows one of those tests.
Compared to 361 running shoes
Number of shoes
5.9 HA
Midsole softness (soft to firm)
35.0 HA

Rocker

The heel of the Atomo Star features a pronounced rocker that starts its curve early, helping smooth transitions for heel strikers and overcome the massive stack height. This geometry, paired with its substantial heel stack, encourages a rolling motion that reduces landing impact and promotes forward momentum.

In the forefoot, the rocker extends early, allowing for a fluid toe-off rather than a sharp push. The gradual upward curve works well for midfoot and even forefoot runners, supporting a natural gait.

Diadora Atomo Star Rocker

Size and fit

Size

Owners of this shoe, how does it fit?

1 size small ½ size small True to size ½ size large 1 size large

Width / Fit

The biggest deal-breaker of the Atomo Star is its fit, built on a classic European last that hardly resembles the natural shape of a human foot and is far from roomy.

Our initial measurement came in at just 89.4 mm, one of the lowest we’ve recorded in a long time. This makes the shoe a better match for runners with narrow feet (and possibly a dream for those who struggle to find snug-fitting options) but a definite no-go for everyone else.

Diadora Atomo Star Width / Fit
Test results
Atomo Star 89.4 mm
Average 95.3 mm
Compared to 190 running shoes
Number of shoes
88.5 mm
Width / Fit
102.4 mm

Toebox width

The snug fit of the Atomo Star extends into the toebox, where we measured only 70.8 mm. Once again, this clearly isn’t a shoe for wide-footed runners.

Diadora Atomo Star Toebox width
Test results
Atomo Star 70.8 mm
Average 73.5 mm
Compared to 190 running shoes
Number of shoes
66.7 mm
Toebox width
82.4 mm

Toebox height

When talking about running shoe fit, most people focus on width, but height matters just as much. That’s why we created the gel method to measure fit in three dimensions for a more complete picture.

In the Atomo Star, we measured an extremely low 22.5 mm, which will only suit runners who don’t mind some pressure on their toes. Adding to this, the retro-inspired design includes hard overlays across the toebox, further restricting vertical movement.

Diadora Atomo Star Toebox height
Test results
Atomo Star 22.5 mm
Average 27.3 mm
Compared to 189 running shoes
Number of shoes
22.4 mm
Toebox height
33.9 mm

Traction / Grip

Traction test

New

The outsole features Duratech 5000 rubber, a name that also packs a distinctly retro vibe. Performance-wise, it delivers impressively, scoring 0.50 in our wet concrete test.

This makes the Atomo Star a reliable choice for tackling all weather conditions year-round.

Test results
Atomo Star 0.50
Average 0.46
Compared to 234 running shoes
Number of shoes
0.11
Forefoot traction
0.83

Outsole design

New

The Atomo Star’s outsole showcases expansive areas of exposed white foam, with sculpted channels dividing the Duratech 5000 rubber into segmented pods that improve flexibility. 

At the heel, we saw that black rubber forms two asymmetrical panels with curved edges and fine grooves, shaped like an angled horseshoe and extending slightly up the sides for a bit more of coverage. However, it’s evident that Diadora prioritised weight savings over rubber coverage with this shoe.

Diadora Atomo Star Outsole design

Flexibility / Stiffness

New

As a maximalist daily trainer, the Atomo Star was never designed for high flexibility given its massive slab of foam. Our lab test confirmed this, recording a 13.8N score—slightly below average yet still on the stiffer side for a plateless running shoe.

Diadora Atomo Star Flexibility / Stiffness
Test results
Atomo Star 13.8N
Average 15.0N
Compared to 237 running shoes
Number of shoes
4.0N
Flexibility <> Stiffness
28.5N

Weight

The Atomo Star isn’t a lightweight running shoe, but considering its substantial build, hitting 9.5 oz (268g) is impressive. Diadora achieved this by pairing an airy, nitrogen-infused foam with minimal rubber coverage on the outsole.

Diadora Atomo Star Weight
Test results
Atomo Star 9.5 oz (268g)
Average 9.3 oz (265g)
Compared to 436 running shoes
Number of shoes
5.6 oz (159g)
Weight
12.6 oz (357g)

Breathability

Breathability was one area that really concerned us when we unboxed the shoe and took a sneak peek at it, due to its lack of ventilation holes and thick upper. So we were eager to advance in our lab review to test it out.

When we plugged the smoke machine into the shoe and hit the button, we were relieved to find a 3/5 score. Sure, it’s not ideal and will run a bit hot on the warmest days, but it avoided a disaster.

Moving the upper over a powerful light revealed no clear spots for air to escape, much like most retro-styled running shoes. The upper design simply follows the shoe’s vintage aesthetic.

Diadora Atomo Star microscope

With the digital microscope, we got a closer look at the engineered mesh.

Diadora Atomo Star mesh

It seems Diadora focused on comfort and a plush, luxurious feel—and we can’t argue with that. They simply had different priorities than ventilation, and that’s fine.

The upper itself is extremely comfortable, among the best we’ve handled in the lab. It offers an exceptional step-in feel with abundant foam in the tongue and heel, and the mesh features a soft, smooth lining inside. Not ideal for airflow, but if that’s not a concern for you, it’s definitely premium.

Test results
Atomo Star 3
Average 3.8
Compared to 365 running shoes
Number of shoes
1
Breathability
5

Stability

Lateral stability test

The Atomo Star offers a stable ride thanks to its wide heel area and the lateral and medial reinforcements, yet it’s not ideal for runners needing real stability. In our opinion, its soft foam and max-stack design suit only neutral runners.

Torsional rigidity

With nearly 40 mm of stack height, expecting this shoe to bend easily would be unrealistic.

Still, the minimal rubber coverage and strategic cutouts give it some flex, earning a 4/5 score. We think that this result is better than a rigid 5/5 for a comfort-focused running shoe like the Atomo Star.

Test results
Atomo Star 4
Average 3.4
Compared to 414 running shoes
Number of shoes
1
Torsional rigidity
5

Heel counter stiffness

The heel counter stiffness scored 4/5, which came as no surprise. We could barely flex it, making it a solid option for runners who need a bit of extra stability in the heel area.

Test results
Atomo Star 4
Average 2.9
Compared to 398 running shoes
Number of shoes
1
Heel counter stiffness
5

Midsole width - forefoot

The forefoot measures just 114.1 mm, which initially caught us off guard. However, there’s a clear reason: its narrow toebox design means it doesn’t require the extra width that roomier shoes use to provide stability in this area.

Diadora Atomo Star Midsole width - forefoot
Test results
Atomo Star 114.1 mm
Average 114.3 mm
Compared to 436 running shoes
Number of shoes
102.2 mm
Midsole width - forefoot
126.9 mm

Midsole width - heel

On the other hand, the heel is huge at 100.2 mm, matching what we see in many supertrainers.

For rearfoot strikers, it offers stability but also feels a bit clunky. Still, it’s a better trade-off than having a highly unstable ride.

Diadora Atomo Star Midsole width - heel
Test results
Atomo Star 100.2 mm
Average 90.7 mm
Compared to 436 running shoes
Number of shoes
70.8 mm
Midsole width - heel
106.6 mm

Durability

Toebox durability

Without ventilation holes, we expected the Atomo Star to perform well in upper durability, especially given its high price. Fortunately, our test confirmed this, landing at a 3/5 score, which is solid enough to pass our standards.

Test results
Atomo Star 3
Average 2.6
Compared to 299 running shoes
Number of shoes
1
Toebox durability
5

Heel padding durability

On the flip side, the heel padding revealed its comfort-first focus with a 1/5 score. This suggests that Diadora may have prioritised plushness a bit too much, as we would have preferred greater toughness in this area.

Test results
Atomo Star 1
Average 3.3
Compared to 294 running shoes
Number of shoes
1
Heel padding durability
5

Outsole durability

The Duratech 5000 outsole proved not only grippy but also exceptionally durable. After testing it with the Dremel, we found just 0.4 mm of wear: a minimal result that’s truly impressive.

Test results
Atomo Star 0.4 mm
Average 1.0 mm
Compared to 277 running shoes
Number of shoes
0.0 mm
Outsole wear
2.0 mm

Outsole thickness

The rubber measures 3.5 mm thick, likely because Diadora wanted to offset the limited coverage—especially at the Atomo Star’s premium price. Still, we believe trimming a millimeter could make it feel softer while maintaining solid durability.

Diadora Atomo Star Outsole thickness
Test results
Atomo Star 3.5 mm
Average 3.3 mm
Compared to 432 running shoes
Number of shoes
1.0 mm
Outsole thickness
6.1 mm

Misc

Insole thickness

The DDATTIVO insole is crafted from high-density foam, fully ventilated for superior moisture absorption, and boasts an impressive 7.5 mm thickness in the heel area.

Diadora Atomo Star Insole thickness
Test results
Atomo Star 7.5 mm
Average 4.4 mm
Compared to 431 running shoes
Number of shoes
1.5 mm
Insole thickness
7.5 mm

Midsole softness in cold (%)

The Anima N2 is an EVA-based foam, which comes with certain drawbacks. One of them is poor cold resistance—after spending 20 minutes in our freezer, it became 32% firmer.

Diadora Atomo Star Midsole softness in cold (%)
Test results
Atomo Star 32%
Average 25%
Compared to 360 running shoes
Number of shoes
1%
Midsole softness in cold
63%

Removable insole

The ultra-plush insole is removable, which is a definite plus. This lets you swap in a thinner one, creating extra space in the toebox, a real advantage in a shoe that doesn’t offer much room inside.

Diadora Atomo Star Removable insole
Test results
Atomo Star Yes

Reflective elements

Diadora made its large logo reflective, and we applaud this design choice. As we found with shoes like the New Balance Fresh Foam X 1080 v14, we think this is the best way to add this detail with style and convenience. And on top of that, they added a two more reflective elements, which is quite impressive!

Test results
Atomo Star Yes

Tongue padding

The tongue packs an impressive 11.0 mm of padding, reinforcing the Atomo Star’s mission to be a super-comfortable running shoe. And while some might feel slightly cramped with so much foam on the instep, let us tell you that the ultra-soft foam never felt oppressive during our runs.

Diadora Atomo Star laces

As for the lacing system, it’s pretty standard, with tried-and-true punched eyelets. And yes, the laces proudly sport yet another “Made in Italy” tag, in case you somehow missed it.

Diadora Atomo Star Tongue padding
Test results
Atomo Star 11.0 mm
Average 5.8 mm
Compared to 433 running shoes
Number of shoes
0.4 mm
Tongue padding
14.2 mm

Tongue: gusset type

The tongue is partially attached to the sides with a thin fabric, an ideal design choice for a premium daily trainer like the Atomo Star. We have zero complaints about this implementation.

Diadora Atomo Star Tongue: gusset type
Test results
Atomo Star Both sides (semi)

Price

This shoe isn’t exactly budget-friendly, especially outside Europe, for one key reason: Diadora manufactures the Atomo Star in Italy and proudly highlights it on the box. 

This brings two considerations: first, exporting beyond Europe makes it pricier, which is the opposite of what Europeans are used to with most brands. Second, crafting shoes in Italy costs significantly more than producing them in Vietnam, China, or Bangladesh. Still, for many runners, this level of local craftsmanship could be a highly positive factor that adds real value.

Diadora Atomo Star Price box
Test results
Atomo Star $240
Compared to 436 running shoes
Number of shoes
£45
Price
£280

Heel tab

The heel doesn’t feature a pull tab but exudes comfort and a touch of luxury. And, again, the Italian flag is proudly displayed!

Diadora Atomo Star Heel tab
Test results
Atomo Star None