About a month ago I received the long-awaited Instinct shoes by Altra Zero Drop Footwear. I have already put almost 150 miles on mine. They have worked so well that I've been too busy running to take time to blog about them.

Prior to owning the Altra Instincts, my weekly footwear rotation included barefoot, Vibram FiveFingers Bikila (VFF), Mizuno Wave Universe 3 (MWU3), and sometimes my Adidas Kanadia 3 trail shoes or Soft Star RunAmocs (and for a short time the New Balance Minimus Road).

I like the Altra Instincts so much that I am running in them almost exclusively. I still try to incorporate at least one barefoot session per week, but I haven't reached for any of my other shoes (including the VFF) since getting the Altras. The experience has led me to question some of my previous notions about minimalist running shoes. Yeah, I like the Altras THAT much.

The Altra Instincts are not minimal shoes. They are fully-cushioned but with zero drop from heel to toe (there is no ramp angle, no differential in sole thickness from the back of the shoe to the front). The front of the shoe is shaped like a foot, so it does not squeeze the toes back together towards the middle of the shoe. There is no extra "stuff" in the shoe to interfere with the human foot's amazing biomechanical capabilities. These features allow one to run with a natural gait and encourages a foot landing on either the forefoot or midfoot (e.g. the whole foot).

These are pictures I took when the shoes were still fresh and shiny:





And here they are on my feet:



And with jeans:



I tried a number of shoe lacing techniques and found that I prefer the Lydiard lacing style, also known as straight / bar lacing (as seen in the first two pictures).

I run without either of the insoles that come with the shoe. Altra includes an arch support insole and a flat insole. I like the slightly firmer feel that comes from having no insole.

Although not as light as my minimalist shoes, the Instincts compare favorably to a typical "trainer" running shoe. Most people I know who have held the shoes say that the Instincts feel very light.

With 150 miles on my Instincts, the outsoles are doing great. There are no signs that they are degrading. I took a close inspection of the stitching last night (both outside and inside) and everything looks just fine. The shoes appear to be very durable. At this point I see no reason why they won't be good for 500 miles or more. I'll post an update to this review if I discover anything notable, but my feeling is that Altra Running has made a quality shoe.

** Update June 7, 2011: I have noticed some compression of the cushion under the ball of the foot. I see that other owners are reporting 250+ miles with no trouble but I have noticed that my Instincts are starting to feel a little bit "flat" after 200 miles. Waiting to hear back from Altra Running on this. ***

** Update October 12, 2011: I heard back from Jeremy at Altra a while ago: "The Instinct does contain EVA below the A-bound in a dual layer midsole. This is something we are going to look into as The Instinct is meant to be a 400 mile shoe in durability." Despite this, I still plan on buying another pair of Instincts as soon as the Black model is available. I still think the Instincts are the best cushioned shoe on the market due to the Zero Drop sole and wide toebox. **

It's an amazing thing to run injury-free! I cannot explain why, but the Instincts are helping to cure my nagging Achilles tendon / bursitis issue. A combination of physical therapy and trying many other shoes did not alleviate the issue. I had become so used to the nagging discomfort over the prior few months that when I finally realized the pain was gone, the absence was quite noticeable, but of course it took a while to notice that something was missing! Whatever it is in the Altra Instinct that is different seems remarkable since the Instinct is the only shoe from my collection that had an immediate and noticeable positive impact on my Achilles injury. I am pretty-well convinced that elevated heels are not a good thing... better technique through natural running form and all that.

In the short time that I have owned the Instincts I have been able to increase my mileage substantially. I ran my first ever (lifetime!) 20-miler last week. I managed over 40-miles total the week before and I've been averaging close to that for the last month. The running is now going so well that I am moving out of a year-long conditioning phase and into harder training / sharpening, hoping to peak for a race in July. I have started incorporating high-intensity workouts. The Altras are working great at these faster speeds.

I had one minor issue with the Instincts that other runners have also reported around the net. The heel counter (the firm area at the back of the shoe that wraps around the heel) tends to rub the Achilles tendon during the first few runs. The cloth shoe liner is actually a fairly coarse fabric and is apparently rough enough to irritate the skin on the back of the tendon. After a few runs wearing thicker socks, I stopped noticing this. I do not have this issue anymore even in my thinnest socks.

I'm still eager to try the additional models from Altra Zero Drop Footwear which should all be available before the end of the year. If the forthcoming Adam and Samson live up to expectations, I may never wear five-toed shoes again.

One more notable thing is that Altra makes a women's version of the shoe, called the Intuition. Altra did not just shrink the men's shoe, they actually adjusted the dimensions to fit a woman's foot (there are apparently anatomical differences between male and female human feet) which is pretty cool.

The Altras are still not available to me locally, so I ordered mine online from the Natural Running Store. I had a great shopping experience with Natural Running Store, Patton Gleason will treat you right, and they are currently offering free shipping on Altras.

** update 5/19/2012 ** Some models of Altra Zero Drop shoes are now available in Gainesville, FL at Lloyd Clarke Sports.