Altra Superior 4.5 Review

The Superior 4.5 is the lightest and most minimal of Altra's trail running shoe lineup. We've been testing and reviewing each new version of this shoe for close to seven years now, and feel that this is the best version yet — but it's not perfect. The most noticeable change is to the fabric of the upper, which is now a bit burlier and shouldn't rip as easily. The padding on the inside of the upper is a bit different as well and feels both a little bit thinner, while also a bit denser. The Quantic foam midsole also feels slightly more robust, despite retaining the same thickness, so that it is a bit easier to run as fast as you want over rocky terrain without turning your feet into hamburgers in the process.

This shoe comes with a removable StoneGuard insert, which is essentially a thin piece of plastic that slots in underneath the insole. While adding this insert does add a little bit of underfoot protection (and weight), even with it in place, this shoe remains one of the most flexible and sensitive you can buy. Adding the insert also changes the volume on the inside of the shoe, and we prefer the fit without the insert added. If you feel like you would like to run with the insert in place, be sure to size up half a size. While many online reviewers complain that this shoe runs small, we feel that it fits perfectly to size without the insert, and fits almost identically to the previous 4.0 version. Frankly, this shoe is awesome because of its very little protection and incredible trail feel, and if these attributes don't appeal to you, or you want something with more protection, we recommend stepping it up to the Timp or Lone Peak, rather than trying to make the Superior with insert work for you.

Performance Comparison

Foot Protection

This shoe is certainly not going to win any awards for its underfoot protection, but the thin, highly flexible feel provided by the Quantic foam midsole has its own appeal. Rest assured, you will be able to feel everything you are stepping on, and this effect suits midfoot strikers far better than heel strikers. It also suits one on shorter runs where the legs are fresh and speed is desired, rather than long runs where tired muscles break down into sloppier technique where the feet take the most abuse. Despite being called a "StoneGuard," the optional insert does little to change this dynamic, except for effecting the fit inside the shoe.

The upper, on the other hand, is fairly protective. The mesh is thick and reasonably tear-resistant, while the majority of the upper is made of a thicker synthetic material that protects the sides of the feet and is resistant to abrasion. The toe bumper is a hard piece of plastic that can take a blow without bruising the toes.

Traction

The Trail Claw outsole made with Altra's MaxTrac rubber has remained unchanged for years, and while we have been apologists in the past, the fact is that these shoes are not very aggressive or grippy compared to most of the trail running shoe competition. With relatively few lugs, small in size, and only about 2-3mm deep, the traction on this shoe is far better suited to simply cruising along hardpacked trails than it is to tackling any soft or rocky off-trail terrain.

We've also been a bit unimpressed with the durability and stickiness of the rubber, having slipped off a couple of dry rocks while out on runs. We've noticed that more than one of the lugs on our test shoes has torn. These shoes are in need of an outsole redesign, one that brings them more in line with what most trail runners expect. That said, for cruising mostly non-technical terrain, they work just fine.

Sensitivity

It's pretty hard to imagine a more sensitive trail running shoe. Even compared to other super minimal options, this one feels even more sensitive due to the fact that the Quantic foam is squishy and collapsible underfoot, rather than stiff and rigid. These shoes absolutely tip the scales far in the direction of "trail feel" and far away from "thick foam cushioning."

While running in such a sensitive shoe feels like an enlightening experience for about 10 miles or so, it can quickly turn into a trying experience (depending on your own fitness of course) as the miles accumulate, and overall fatigue starts to catch up with you. We find that as we get tired we tend to rely on the protection of our shoes far more, and unless you have the strength, focus, and patience to maintain proper form when tired, the Superiors can start to feel a bit too minimal.

Stability

The Superior 4.5 is an incredibly stable shoe. More than any other option, it allows the foot to act exactly as the foot would if it was not wearing a shoe. The zero-drop platform that sits very close to the ground is the main reason this shoe works so well. Its relatively wide forefoot allows the foot to splay out as it lands and pushes off also helps.

In stark contrast to stiffer shoes with rock plates or more foam underfoot, this shoe is highly flexible, such that it will adapt to anything that you land on. This can stress and tax many of the muscles in the foot, ankle, and lower leg while running, in a good way that leads to overall better health of the muscles and connective tissue over the long run.

Comfort

These are some extremely comfortable shoes, even right out of the box. They are so comfy that we often use them as our daily tennis shoes for wearing outside while gardening or when walking around town. The upper is very well constructed, and the burrito-style tongue, which is attached on one side and then wraps over the top of the foot, has no creases or weirdly sewn seams that can rub while running. It's honestly hard to imagine a more comfortable shoe.

The fit, like most Altras, remains slightly short. We actually feel that compared to most Altra shoes we have tested (many!), these are among the closest to true to size. However, they aren't the snuggest and precise fitting due to the wide forefoot and toe box, and thus our feet sometimes slide forward on long downhills so that we can feel our toes in the front. In a neutral position, there is plenty of room between the toes and the front of the shoe, and compared to the majority of trail runners, these shoes fit on the wide side.

Weight

Our size 11 men's shoes weighed in at 18.6 ounces per pair, or 9.3 ounces for an individual shoe, which was actually slightly lighterthen we weighed the Superior 4.0s at. Competing internet reviews claim that the shoe has gained weight this iteration, but we haven't found that to be the case. Due to manufacturing inconsistencies, there is always going to be some variance of weight from shoe to shoe, and it's also possible that our pair came out on the lighter side. Even if it is listed as slightly heavier, the differences are so small as to be a negligible concern.

These shoes are easily among the lightest in this review, and anecdotally, feel very light and minimal on the foot. The light weight is one of the principal reasons for choosing this shoe and contributes positively to the overall feel of running in them – unless you are a runner who simply wants protection in the form of a stiff midsole.

Value

These shoes have retained their same low price point, and are one of the more affordable trail running shoes you will find these days. However, being zero-drop and quite minimal, they are certainly a niche shoe. If you like the qualities that come with running in the Superior, then we think they present pretty awesome value and are a shoe that reminds us of all that we like about Altra shoes. If minimal and zero-drop aren't your cup of tea, then these shoes will probably feel like a rip-off, and we recommend you stay away.

Conclusion

The Altra Superior 4.5 are a minimally updated version of the Superior 4.0. They have a slightly more robust upper while maintaining their light and fast feel and appeal. We think they present the budget-conscious minimalist runner a great value and concede that they are not going to appeal to everyone.