Comfortable, durable upper review

are known for their spacious uppers:

• Runners previously hesitant about Altra's zero-drop design, now welcoming the new low-drop option that makes it accessible to more runners.
• Altra enthusiasts who've experienced calf or Achilles discomfort, as they will find the slightly higher drop beneficial while still enjoying the roomy foot-shaped toebox.
• Those with wide feet, as this low-drop, spacious daily workhorse also doubles as an excellent choice for travel or everyday wear.

The Comfortable, durable upper marks a significant step forward for the brand, opening doors to new enthusiasts who were previously deterred by the zero-drop design.

However, it's not without its flaws—the EVA midsole's lack of energy return is noticeable, particularly when compared to peers like the best Altra running shoes or the oz / 215g. For those comfortable with a higher drop and narrower toebox, both alternatives offer a more dynamic experience.

Additionally, we found that purists who favor zero-drop and minimal cushioning might not find the Experience Flow appealing. We suggest they consider the Altra Escalante 4, which stays true to Altra's classic design and better suits their preferences.

Altra reports the stack height of the Experience Flow as 32/28 mm for men and 30/26 mm for women. We measured 30.7 mm at the official World Athletics measurement point in the heel, closely aligning with Altra's specifications.

This design offers a well-balanced ride for a daily trainer—not quite maximalist, yet it provides ample cushioning that is ideal for both short and medium distance runs. However, we must note that the shoe appears taller than it actually is due to the midsole sidewalls in the heel area—it's not as high as it seems!

Next, we used our digital calipers to measure the forefoot thickness at 26.6 mm—providing ample cushion for both forefoot and midfoot strikers.

Let's address the elephant in the room. Die-hard Altra enthusiasts might feel let down by the company’s pivot from its strict zero-drop philosophy—yet, for others, this was the awaited moment to finally give Altra a try. Now, they've rebranded themselves as a "Zero-to-Low drop" company—not strictly "Zero-drop" anymore.

The Experience Flow introduces a 4.1-mm drop, which is high enough to entice runners accustomed to mainstream brands without sacrificing the unique qualities that define Altra, like the foot-shaped toebox.

As long as Altra continues to produce zero-drop shoes—a commitment they have reassured in multiple interviews—we believe this expansion into the low-drop realm can only broaden the choices available to all runners, a development we view as a win-win situation.

Altra opted for a standard compression-molded EVA foam that delivers subpar energy return and a ride that’s neither plush nor firm, just average. And boring.

This is tolerable for a $140 shoe, yet it feels like a disappointment given the shoe's overall potential. Altra possesses Flexibility / Stiffness that could enhance this model significantly. Unfortunately, it seems they might be holding back to avoid cannibalizing sales from their higher-end models.

Crafted from EVA, we anticipated only average results in our freezer test. This time, it performed more or less as expected—the midsole hardened by 23.5% after chilling for 20 minutes next to our ice-creams.

During our test runs, the standard insole performed flawlessly. We later measured it and confirmed its thickness at 4.7 mm.

The Experience Flow features only a slight curvature at the heel and toe, subtly aiding the toe-off phase during runs. We believe that any more pronounced rocker would be excessive, especially given Altra's philosophy of promoting a natural running experience.

As it happens with any Altra shoe, the foot-shaped design is the star of the show. To prove that, we created a gel mold to take proper measurements.

By the way, the Experience Flow features Altra's Standard Footshape, which sits between the Original and Slim options. In other words—it’s a roomy fit (98.5 mm) compared to most shoes but just average within this brand.

The real deal is revealed in our second measurement of 80.6 mm—it confirms that the toebox features an anatomic shape, perfect for runners with wide or square feet, ensuring a comfortable, unconstrained fit.

This design shines for easy or moderate paces, but it may not be ideal for faster speeds. Why? Most running shoes limit toe splay to enhance performance by reducing the dissipation of lateral forces. But at easy paces, who cares about gaining 1% speed at the expense of comfort?

The trifecta of measurements we performed on the gel mold brought great news for fans of high-volume uppers. We recorded 29.0 mm, ensuring ample room for both vertical toe movement and lateral freedom.

One of the standout qualities of the Experience Flow is its ability to offer remarkable support despite not being a traditional stability shoe. It boasts a low-drop geometry, broad landing platform, balanced foam and robust sidewalls—all contributing to a really stable ride.

Even those needing mild support needs will find much to appreciate in the Experience Flow design!

While Altra shoes are often thought of as barefoot-like and flexible, not all fit this mold. In fact, Altra offers a range of models from highly flexible to stiffer options. The Experience Flow represents a balanced choice with a 3/5 flexibility score in our testing, positioning it solidly as a typical daily trainer.

In our evaluation, the heel counter of this shoe showcased a standard stiffness level with a 3/5 rating.

While the Experience Flow accommodates heel strikers with its moderate drop, it truly excels for forefoot and midfoot strikers—not just for this reason, but also due to its expansive landing platform, providing exceptional stability with a width of 118.4 mm in this area.

The heel is slightly wider than usual, measuring 93.2 mm, subtly encouraging heel strikers to give this Altra a try.

During our evaluations, the Experience Flow excelled in delivering a smooth, natural run, devoid of any underfoot stiffness. Lab results reinforced our thoughts, showing that minimal effort (13.5N) was needed to flex the shoe to 30 degrees.

The upper of the Experience Flow definitely impressed us, and the shoe's weight is equally amazing.

At just 8.3 oz or 235g, this stands out as one of the lightest daily trainers on the market—and it's no easy feat given its wide design. For context, the Nike Pegasus 41 weighs 9.9 oz or 281g!

At first glance, the bi-color engineered mesh upper of the Experience Flow might not seem very breathable—there are zero visible ventilation holes and what seems to be a thick fabric. However, a different story unfolded in our lab.

It's quite uncommon to discover smoke coming out from the sides.

We used the smoke-pumping machine and also a powerful light during our tests, and discovered ultra-thin areas strategically placed throughout the upper. This clever design contributed to the impressive 4-out-of-5 breathability rating we gave to the Experience Flow.

As we said just before, one particularly cool detail we uncovered was Altra’s strategic placement of ventilation. Contrary to typical designs of running shoes, Altra emphasized ventilation along the sides rather than in the toebox, which is reinforced likely to enhance durability.

Upon further examination with a microscope, we confirmed that there are indeed no traditional ventilation holes; it's just an average mesh that subtly opens up every now and then to improve air flow.

We discovered that the upper of the shoe combines two distinct sections: the rear is exceptionally pillowy and comfortable, equipped with two lateral foam pads—a rare feature—while the midfoot and toebox sacrifice padding to boost ventilation.

In our previous test, we speculated that the design aimed to boost durability in the toebox—and our tests with the Dremel confirmed just that.

Altra truly excelled this time, scoring a perfect 5/5 in durability—a rare achievement for a road running shoe.

With high expectations for durability, we were eager to test the heel padding of the Experience Flow.

Following our second Dremel test, we discovered a positive outcome—awarding it a 4 out of 5. Although it didn't achieve the highest rating, it significantly surpasses many other shoes, demonstrating robust durability.

After being thoroughly impressed with the upper, we shifted our focus to the outsole. Here we discovered the signature Altra design that many runners appreciate, featuring lots of rubber covering the forefoot, midfoot and most parts of the heel. 

Regarding the rubber composition, it tested at an average hardness of 78.8 HC. We are eager to conduct further testing to delve deeper into its durability.

We cranked up the Dremel again—this time at a robust 10K RPM and for a prolonged period.

The result was not so good, as we found a 1.2 mm dent. It's not alarming enough to cause serious concern, but it does highlight the need for refinement in the next iteration. On the plus side, we discovered the grip to be quite good on both roads and smooth dirt tracks.

We also assessed the outsole's thickness—measuring it at 2.5 mm, we found it strikes a nice balance between weight and durability, especially considering the previous result.

For just $140, you get more than a great daily trainer—you also receive supercool reflective laces that enhance safety!

This is not just another daily trainer with a pillowy tongue, but one of the select few boasting a massive 9.3 mm cushion while maintaining a weight under 9 ounces. That's incredible.

The lacing system impressed us too, devoid of unnecessary frills but perfectly effective. It features plain laces of adequate length, punched eyelets, and the welcome option of an extra eyelet if needed. That's all we ask for, and most brands just keep reinventing the wheel here with weird lacing systems.

One noticeable shortcoming of the Experience Flow is its absence of a gusseted tongue—a slightly disappointing miss even for a $140 daily trainer. Although budget constraints are understandable, the inclusion of a gusseted tongue would have been a smart feature in this shoe, particularly since Altras are known for their spacious uppers.

Altra has revamped its design with the Experience saga, introducing a new heel area that evokes mixed feelings for us. The extended heel is stylish and convenient, yet we feel the collar is too low around the ankle, which might be a concern for some runners.

Removing the insole was a breeze for us since it isn't glued down—however, since this is an Altra shoe with its distinctive broad toebox, swapping in an insole from another brand or a custom footbed might not fit perfectly due to its design.