Latest revision as of 09:20, 30 August 2018

The Altra Instinct 4.0 is a much better shoe than the previous 3.5 version, and comes a surprisingly close to my favorite iteration, the 2.0 version. The cushioning-to-weight ratio is pretty much the same as the 2.0, with the 4.0 being slightly lighter, and slightly less cushioned. This version of the Instinct is a smooth riding shoe, with nothing much to interfere with your biomechanics. I do feel that the cushioning is a little less springy than I would like, and feels just slightly dead. The shape matches the human foot nicely, so it doesn't crush your toes, though I do wish there was more height in the toe box. The upper is nicely breathable and open, and it's a comfortable shoe even though it's not got to the excessively padded, skateboard feel that the 2.0 did. I rated the Instinct 4 as "Worth Considering", as it's a good choice, but there are a number of shoes that are better. (I use The Science of Running Shoes as the basis of how I test running shoes and what you should look for in a running shoe.)

Altra Instinct 4.0 top	Altra Instinct 4.0 bottom
Altra Instinct 4.0 inside	Altra Instinct 4.0 outside

1 Characteristics

• Cushioning . The Instinct 4 has a reasonable cushioning-to-weight ratio, and it's an improvement on its predecessors. The cushioning is reasonably smooth and even, but I find it a little "dead" and lacking in the bounce. This is particularly noticeable after wearing the Altra Escalante, but that's an exceptional shoe. The latest version is a little closer to my favorite, the Altra Instinct 2, though I know other runners and found that a little too squishy.
• Drop. Like all Altra shoes, the Instinct claims to be zero drop. My measurements indicate that it's actually slightly negative drop, with the forefoot a little thicker than the heel. I doubt if many runners will notice this, and I wouldn't let it put you off if you're off to a zero-drop shoe.
• Structure. The Instinct uses just one density of foam, and doesn't attempt to manipulate or interfere with your natural biomechanics. The midsole is not completely flat, with some rise under the midfoot. I'd say the Instinct 4 has less of a molded shape than most running shoes and you may find it feeling rather flatter than other shoes.
• Flexibility. The Instinct has more flexibility than I expected, and it's similar to the Hoka Clifton, but far more than the other Hoka shoes. However, the flexibility doesn't have much spring to it, which may reduce your Running Economy. Personally, I'd rather have more flexibility or the same flexibility with more spring.
• Outsole. There's a good layer of harder rubber outsole that effectively covers the entire sole of the shoe. There's a few gaps to improve flexibility, but coverage is good. a gap in the outsole near the smaller toes, which is an odd choice, but doesn't cause a problem. The sole of the Instinct does not conform to stony trails in quite the same way that many of the Hoka shoes do, and there's no grip on the outsole, so it's best kept for road running.
• Shape. The Altra Instinct is designed to fit the human foot, and they mostly get it right. The shape is a little overly stylized, and doesn't provide enough room for the big toe to display out. I found that there wasn't quite enough headroom in the toe box and my toes eight after an hour or so. This is another area where the Instinct 2 was better, as the toe box height seems to be reduced with each version. (I recommend cutting open the toe box of virtually all running shoes, with the exception of a few shoes like some Altra shoes. When you have some worn out shoes, you should try cutting open the toe box. I've found that it's a big improvement, allowing my toes to move naturally and engage for toe off, as well as reducing the possibility of blisters.)
• Upper. The upper is quite breathable, as you can see from the backlit photo below. The ankle opening is fairly well-padded, but doesn't have the extreme adding that the Instinct 2 had that made it feel a little like a skateboarding shoe. There is a reinforcement patch around the extreme front, acting as a toe bumper, but I didn't feel that this impact on my toes. On the other hand, I doubt if it will give much protection from stubbed toes either. For some reason, the grey reflective stripe with the Altra name and logo on it is actually a loop that you could start something into. It's not clear to me what this is for, so let me know in the comments if you have any insight.
  
  

  A shot of the Instinct 4 backlight to show breathability.
• Tongue. The Instinct has a traditional tongue with a tab to attach it to the laces. It's extremely well-padded, but perhaps just a tad short.
• Lacing. The traditional flat laces stayed tied. This is such a simple thing, but it seems like most shoe companies are able to get this wrong.
• Heel Counter. The Instinct has a large, ridged heel counter, but the upper is sufficiently padded to isolate you from this. It's unlikely to have any effect unless you twist your ankle, in which case it could dig in

Please support this site This review was made possible by readers like you buying products via my links. I buy all the products I review through normal retail channels, which allows me to create unbiased reviews free from the influence of reciprocity, or the need to keep vendors happy. It also ensures I don't get "reviewer specials" that are better than the retail versions. Buy Altra Instinct 4 at Zappos Buy Altra Instinct 4 at Road Runner Sports Buy Altra Instinct 4 at Kelly's Running Warehouse Buy Altra Instinct 4 at Charlotte Ultra Running Company

2 A Comparison with other Recommended Shoes

If you're looking for "the best of the best" running shoe, here are my top picks. Of course, the answer will depend a little on what you're looking for, so I have recommendations for various categories. Best All Round Shoe. The Altra Escalante is my current all-round favorite. It has plenty of cushioning for its weight, it has a very springy midsole, it lasts well, and it has a shape that's closer to the shape of a human foot than most shoes. It's a great shoe for any runner, including those Starting to run. It's also a fairly easy shoe to find due to its popularity. Best Maximalist Shoe: If you want something massively cushioned, then I'd recommend the Saucony Kinvara 8. It's remarkably light and remarkably cushioned, beating Hoka at their own game. Best Optimal Shoe: For those looking to trade cushioning for speed, the Nike Zoom Streak LT 3 was my top pick, but the latest version (LT 4) falls short of it's predecessor. There are lots of great optimal running shoes, which provide just enough cushioning with light weight and minimal frills, but all have their weak spots. Probably the best option at the moment is the Altra Vanish-R, which offers great cushioning for just over 5oz/150g. Fastest Shoe: If you really want speed, then check out the Nike Vaporfly 4%. It's light, massively cushioned, and has a carbon fiber plate. Nothing comes close, not even the now defunct New Balance RC5000‏‎ or New Balance RC5000v2‏‎. There are a number of caveats; it's really expensive, it's really hard to find, and there's a significant injury risk. Best Minimalist Shoe: Merrell Trail Glove. I recommend the trail glove for road running in spite of the 'trail' moniker. It's not a fast shoe by any means, but it's comfortable and will last well. All Terrain Shoe. For trail running, I've become a fan of Altra, and I think their best shoe is the the Altra Timp, though the Altra Lone Peak is really close. Honorable Mention: It's not really a running shoe, but the Vivobarefoot Ra is comfortable, minimalist and can more or less pass as a dress shoe. I've worn mine to weddings with a suit and they've not looked out of place. You can run in the Ra, but the leather means it doesn't breathe well.

For a more detailed on running shoes see the Recommendations for Best Running Shoes. This table lists the key attributes of What to Look for in Running Shoes. For more detailed information, on the shoes see detailed shoe comparison.

It's not a running shoe, but I love the Hoka Tor Ultra hiking boot and I've tested the Altra Lone Peak Boot, the Hoka Tor Speed 2, and the Inov-8 Roclite 325 hiking boots
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