Have you read Shoes Are Tools yet? If not, you might want to check-it-out. One of the things I state in that article is that I believe the purpose of footwear should be:

...to provide maximum feel and dexterity and minimum restriction while providing only the protection that is necessary.

That little phrase "protection that is necessary" has a lot of room for interpretation and therefore I see a place in the minimalist footwear market for a wide range of designs. If the only activity you do is short runs in pleasant weather and spend the rest of your time indoors, your idea of the ideal shoe will be a lot different that someone who thru-hikes the CDT or treks for an entire year (i.e. all four seasons) along the west coast to Alaska.

Footwear design elements I consider non-negotiable are: minimal heel rise (preferably none); no motion control or structure designed to alter the gait (i.e. a neutral design); and an anatomical last with adequate room in the toebox.

A few other shoe design qualities are what I consider a grey area. Things like water resistance, upper stiffness, sole stiffness, and cushioning. They make sense in some but certainly not all situations. The question you need to ask yourself when selecting a shoe is this:

What adverse environmental condition am I protecting myself from with this design?

This brings us to the Altra Instinct. The Instinct has all of the non-negotiables: A wonderfully shaped anatomic last, zero-drop, neutral structure, and no arch support. It also sports a nice breathable/flexible mesh upper. It then delves into the grey area by stacking all of that minimalist goodness on top of a cushioned sole.

For most activities I prefer to have a thin-soled, highly flexible minimalist shoe (i.e. shoes like the Altra Adam). So, where do I see the Altra Instinct fitting into my shoe quiver? I see it as being useful to me in a couple of areas:

• Winter running: in cold weather, insulation (i.e. foam) under the foot goes a long way to keeping feet warm. In fact, I find that if I have adequate warmth on the bottom of my feet, the warmth of the uppers doesn't matter too much. Up until recently my preferred winter running shoe was a pair of Inov-8 Orocs, oversized to give my toes wiggle-room. Now that I have a pair of Instincts, the Orocs are going to get retired.
• Hiking and backpacking: depending on the distance and terrain, having some extra protection under foot can be really nice, especially in very rough conditions. Since the Instinct doesn't have a rock plate, it maintains a measure of flexibility while providing extra protection from pointy things. Although it is considered a road running shoe, I find the tread to be more than adequate for trail use - it certainly isn't any worse that the New Balance Minimus Trail, Merrell Trail Glove, or Inov-8 F-Lite series. (For off-trail use - i.e. mud, loose dirt, tundra, etc. - a deeper lug is better, which is the niche we hope the Altra Lone Peak will fill).

Enough about the theory... how do the shoes actually work?

I like the simplicity of the shoe's no-nonsense design. This is a neutral shoe and it's construction makes that abundantly clear. It isn't covered in high-tech looking fabrics and doodads. It is has a mesh upper, a foam midsole, a rubber outsole and laces. Just the basics, which is all that I ask for.

The fit - for my feet - is very good. The mesh is soft, comfortable, and with enough stretch to mold to the foot. The toebox is excellent, with lots of room for the toes to naturally spread. I found them to be well tailored to my feet, snug in all the right places and roomy where it matters. The net effect is a shoe that walks the razors edge - rather successfully - between security and freedom.

I tested the shoes for a variety of activities which included walking, running, and hiking. I found the cushioning to be firm, which I think is good as I don't like a squishy ride. The downside of course is that along with firm cushioning comes a loss of ground feel. For walking and running, that loss of ground feel was more than I prefer - I would much rather wear the Adam. For winter however, I think the Instinct will work very well as the Adam gets pretty chilly when the temperature starts to drop.

On the trail the performance of the sole is a different story. When walking and running over rocks, roots, and other trail shrapnel, the ground feel isn't all that bad (although I would prefer just a wee bit more). As would be expected they offered lots of protection, and the grip of the sole worked surprisingly well. The softness of the upper was very comfortable. Hiking with these shoes was overall a very pleasant experience, although I did find my feet sliding forward a bit on the downhills.

Concluding Thoughts

If you are a die-hard minimalist then you probably won't like this shoe for warm conditions. For cold weather usage however, I think they are an excellent choice for active pursuits. For less active use in cold weather the uppers will probably be a little too airy.

For those of you looking for a rough terrain minimalist shoe, I would put these on a similar plane as the Luna Leadville or LeadCat sandals. They offer significant (if not a bit excessive) protection, decent flexibility, and a wonderful toebox. To boost the durability for trail conditions I would probably paint over the stitching with seam grip to provide a little more abrasion resistance. If I were to suggest any improvements for this shoe, it would be that Altra consider scaling back the cushioning just a little to improve ground feel.