A few months ago I contacted Altra, a U.S.-based company, asking to buy an Instinct. I’m based in the Netherlands, and Altra’s shoes are not available in Europe. The shoes arrived, and the result of the investigation is below.

A little research will tell you Altra is a small and relatively new brand in the shoe busines, but the people behind Altra are have a long pedigree in the industry. They are not new to running. And, these days, small is okay. It’s no longer the barrier to entry it once was. Look at what happened to Newton.

My interest in Altra’s shoe was in its shape. If you look at it from the bottom, the shape is atypical, and Altra calls it a “natural foot shape.” Look at the sole and it looks like, well, like a foot. Maybe part human foot, parrt duck foot.

Having a duck-footed running style—which places me in Dave Scott's company, so, it’s not all bad—and wearing shoes that resemble the same foot shape got me my share of quack quack comments from onlookers.

But, boy, if you get over the unsolicited commentary, these shoes are comfortable. The moment you put them on you have room for your forefoot, which relaxes involuntarily, and that feels weird.

These are natural running shoes and built on a zero-drop platform—no elevation difference between heel height and forefoot. They are completely flat. So you need to run in these shoes using the form that complements them. They’re less well suited to heel strikers. If you are running with an appropriately clipped stride (not overstriding), with a midfoot-concentrated footfall, and you think you are ready to go to zero-drop, this is a shoe that combines nice, not-too-soft, cushioning with an excellent shape.

The Altra Instinct is flexible, it has few or no seams, no other pressure areas that rub against your feet. Not even when running sockless in them. The first few times I ran in them I noticed a unique sound. Inside the shoe, on the upper, in the forefoot, there is a piece of material that makes a crackling sound with every step. I contacted Altra about this and they told me they knew about the issue and that it should disappear after a few runs and, so, it did. But in the next model year the material probably will be changed.

The heel cup is soft and forms around your heel, but it isn’t a heel cup as you would find in an Asics or a Brooks shoe. It’s much softer than these, and some of you will find they are not supportive enough. This is common in natural running shoes.

Traction can be a little tricky on wet surfaces. I had some runs in very wet conditions, and even once in snow, and there you need to be careful. Or, buy the trail version.

These shoes run great, but there’s more to it. They actually felt so comfortable that I started wearing them to my job in my running and triathlon store. I’m often on my feet, walking around helping customers, performing bike fits, building bikes, and normally after a day of work I always get tired feet.

It struck me after a couple of days that I didn’t have tired feet on these shoes at all. So I went back to some other shoes and rotated wearing the Altras with the shoes I typically wore. On the days I did not wear the Altras I got tired feet at the end of the day. I also felt more relaxed in my lower back, which is where I’m naturally weak.

As of this writing I’ve worn them three weeks in a row without a single day of tired feet, so there is something about this shoe that makes it work very well for me. Whether it’s the zero drop, the material, the specific foot shape, or some combination, I don’t know. They just work. But working in these shoes is not a sensation I’m used to. Wearing the Altra feels like walking around the store on bare feet.

Every pair of Altra Instinct comes with two insoles: One with a little arch and one completely flat. You choose your preference.

The shoe comes in gender-specific colors.