Adidas Adizero Evo Prime X: What We Know

Lightning Strikes Twice

When the Adidas Adizero Pro Evo 1 released two years ago, it was the first race day shoe to really shake things up since the release of the Nike Vaporfly in 2017. Plenty of shoes came with carbon fiber plates, but none of them weighed less than 5 ounces for a shoe designed for the marathon distance, a benchmark that seemed nearly impossible to achieve.

Adidas made it happen with the Pro Evo 1, utilizing an uncompressed block of midsole foam attached to a barely-there upper, finished off with an ultra thin (and ultra slick) rubber outsole. Shortly thereafter, Tigst Assefa wore the shoe en route to a world record finish at the 2023 Berlin Marathon and the rest is history.

Surely, that’s the limit. Right?

Turns out, history can be repeated and Lightstrike lightning can strike twice. Because Adidas just unveiled the Adizero Evo Prime X, a monstrous racer designed specifically for a roster of its athletes and their attempt at breaking the world record for the 100K distance.

Here’s a look at what we know about the shoe that is looking to change the game again.

The Basics

Let’s start with the basics. This is a shoe that came together in just 5 months as an R&D project for the Chasing 100 event, where Adidas athletes lined up at midnight on August 25 at the Nardo Ring, a high-speed test track in Italy, in an attempt to break the world record for the 100K distance.

So this isn’t a marathon shoe. This is a shoe designed to go long distances, fast. For this particular effort, each pair of footwear has been customized for each athlete, with customized stack heights, foam densities, and outsole patterns. Those versions are only for the project, but a slightly different version will be available to the general public in limited quantities this November.

Of course, at 50 mm of stack height, this shoe is not race legal by World Athletics standards, so if you’re an elite athlete trying to win a race on the world stage, maybe opt for its short stack sister in the Pro Evo 2. The name, of course, is a reference to Adidas’ highest stack shoe, the big and bouncy Adizero Prime X3 Strung.

As we already stated, this shoe is impossibly light, even by Pro Evo 1 and 2 standards. It comes in at the same weight as those models, a minuscule 4.7 oz. (137 g) for a US M8.

Let’s take a look at what else is inside.

The midsole

The foam is a finely tuned Lightstrike Pro Evo. The foam compound itself is around 35% lighter than that used in the Pro Evo line. This lower-density material allows for more cushioning volume without increasing the overall weight.

The heel carries about a quarter more foam than a standard Evo 2 (roughly 50 mm in the heel), paired with a 6 mm drop. That extra stack obviously puts it outside of World Athletics compliance, but since this pair was designed for this specific race, regulation wasn’t the top priority.

The outsole

Instead of a uniform rubber base, the team developed a dual-compound system: a wafer-thin traction layer under 0.5mm thick, reinforced in targeted areas with Continental rubber. Using athlete-specific data captured from treadmill sensors, designers mapped out each runner’s strike pattern and applied grip exactly where it was needed. We’re interested to see what this is like in a race day scenario, especially with any degree of moisture. The rubber on the Pro Evo 2 was a downright disaster in less than ideal conditions, so we can only assume this is an upgrade.

The plate?

Rather than relying on a standard carbon plate or fixed insert or even the standard EnergyRods found in most Adidas race shoes, the shoe integrates engineered stiffening elements that vary depending on the athlete. Adidas kept this very vague, without giving information on the name of “the thing” inside or the material. 

However, we have seen what looks like a carbon fiber, EnergyRod-like rim in some other videos, though that would seem to add significant weight if it were the case.

The upper

Here the shoe stays with the same upper as the Pro Evo 2 model, which is what the athletes preferred.

But one more thing… Ultracharge!

Adidas also showed us something called Ultracharge. Is something similar to a small gas tank. Here they put the shoes inside and they get pressurized, similar to tennis balls or tires. They discovered that the foam can be “marinated” up to five days prior to adjusting its density. Basically, upgrading the shoe’s responsiveness a little more. You can clearly feel the difference in the one ultracharged and the one from the factory. Mostly in the energy return. 

This adjustment will also be customized to each athlete for the race.

Availability

As the shoe was done in 5 months and each one customized for the athletes, there still needs to be some fine tuning for a general release, so the specs may vary. That said, there will be a limited release in November. No price yet set, but expect this to be at least the same as the Pro Evo ($500).