Revision as of 04:57, 13 August 2016

The Altra Instinct 2 was a favorite shoe because of its comfortable and design, but the updates since then have been a gradual decline. Each iteration has become slightly firmer, resulting in a shoe that's too heavy for the cushioning it provides. I still like it for being designed to fit the human foot, but I'd far rather cutting open the toe box of a Hoka Clifton or an Asics Gel Hyper Speed. That said, the Instinct 3.5 has no flaws or reasons why you wouldn't want to run in it; it's just that there are better options available. I've rated the Instinct 3.5 as "worth considering", and the Instinct 2 as I've rated it as "Highly Recommended." For reasons known only to marketing people, the Women's version of the Instinct is called the Intuition. (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 3.5 top	Altra Instinct 3.5 bottom
Altra Instinct 3.5 inside	Altra Instinct 3.5 outside

1 Characteristics

• Cushioning . The Instinct is too firmly cushioned for its weight, with similar levels of cushioning to shoes that are much lighter. The cushioning it provides is smooth, even, and has reasonable spring, so don't think this is a rock.
• Drop. Like all Altra shoes, the Instinct is zero drop, which is great.
• 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 flat however, with some rise under the midfoot.
• 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.
• Outsole. There's a good layer of harder rubber outsole over nearly the entire sole of the shoe. There's a gap in the outsole near the smaller toes, which is an odd choice, but doesn't cause a problem. (I have no signs of wear on my Instinct 2's after many, many miles.) The sole of the Instinct does not conform to stony trails in quite the same way that many of the Hoka shoes do, so it's best kept for road running.
• Shape. The Altra Instinct is one of the few shoes truly designed to fit the human foot. Even some other Altra shoes have a toe box that lacks sufficient height, but the Instinct is remarkable in its fit. However, 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 it has a thick overlay that goes over the big toe which I didn't like. It's not enough to cause me problems, but I could see it being an issue for some runners. The forefoot area is unpadded, but generously padded in the rear. It's not like the second version that reminded me somewhat of a skateboarding shoe but it's still pretty good.
• Tongue. The Instinct has a traditional tongue that is sown in on one side, which I think is the ideal approach for a tongue. This is the only improvement I noticed over earlier versions of the shoe. Like much of the upper, the tongue is softly padded.
• Lacing. The traditional flat laces stayed tied.
• Heel Counter. The Instinct has a far more ridged, exoskeleton heel counter than I'd like, but the thick padding isolates it from your foot.

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 3.5 at Zappos Buy Altra Instinct 3.5 at Road Runner Sports Buy Altra Instinct 3.5 at Kelly's Running Warehouse Buy Altra Instinct 3.5 at Charlotte Ultra Running Company

2 Cushioning and Shoes

It's intuitively obvious that the cushioning in a shoe will reduce the impact on your body when running. However, The Science of Running Shoes indicates that the reality is rather more complex. While slight cushioning may reduce the effort needed to run by improving your Running Economy, most scientific research indicates that more cushioning does further improve Running Economy. In addition, cushioning does not generally reduce impact and may actually increase it. This is counterintuitive, but is likely to be due to the way a runners mind and body adapts to softer cushioning. Unfortunately, the scientific evidence is far from complete and it's hard to give clear recommendations. I believe that some runners will prefer more cushioning, while others prefer less, and typically those running further have a fondness for greater cushioning. I also believe that a shoe should be as light as possible, and a shoe should justify its weight with the cushioning it provides. My advice is to decide what level of cushioning you're looking for, and then find the lightest shoes that also fit well and are comfortable.

3 Visualizing the Attributes of the Altra Instinct 3.5

How Altra Instinct 3.5 compares showing rearfoot cushioning against the performance penalty of its weight. Upper right is better.	How Altra Instinct 3.5 compares showing forefoot cushioning against the performance penalty of its weight. Upper right is better.
How Altra Instinct 3.5 compares showing the price against the benefit (cushioning/performance penalty). Upper left is better.	How Altra Instinct 3.5 compares showing the loaded drop against the benefit (cushioning/performance penalty). Upper left is better.

4 Comparisons

Here are some direct comparisons with its potential competition.

4.1 Altra Instinct‏ 2, 3, and 3.5

The Instinct 2 was softly cushioned, which made it a remarkably comfortable shoe, even though it wasn't up to the cushioning-to-weight level of shoes like the Asics Gel Hyper Speed. Each subsequent iteration has made the Instinct firmer, though the change from the Instinct 3 to the 3.5 is quite small. The Instinct 3 is lighter than the 2, though the 3.5 erodes some of that advantage. The other noteworthy change is in sizing; a size 10 Instinct 2 is the same size as a size 10.5 Instinct 3, while the 3.5 returns to the original sizing.

Altra Instinct 3.5 top	Altra Instinct 3.5 bottom	Altra Instinct 3.5 inside	Altra Instinct 3.5 outside
Altra Instinct 3 top	Altra Instinct 3 bottom	Altra Instinct 3 inside	Altra Instinct 3 outside
Altra Instinct 2 top	Altra Instinct 2 bottom	Altra Instinct 2 inside	Altra Instinct 2 outside

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 2 at Zappos Buy Altra Instinct 2 at Road Runner Sports Buy Altra Instinct 2 at Kelly's Running Warehouse Buy Altra Instinct 2 at Charlotte Ultra Running Company

4.2 Altra Instinct‏ and Asics Gel Hyper Speed

The Asics Gel Hyper Speed provides more cushioning in the heel than the Instinct and similar cushioning in the forefoot, even though the Hyper Speed only weighs about two-thirds as much as the Instinct. This makes the Hyper Speed the clear winner, over the Instinct 3.5. (The Hyper Speed is far from uncomfortable, but when my feet are tired and beaten up, the softness of the Instinct 2 was welcome, but that's not the case with the Instinct 3.)

Altra Instinct 3.5 top	Altra Instinct 3.5 bottom	Altra Instinct 3.5 inside	Altra Instinct 3.5 outside
Asics Gel Hyper Speed 7 top	Asics Gel Hyper Speed 7 bottom	Asics Gel Hyper Speed 7 inside	Asics Gel Hyper Speed 7 outside

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 Asics Gel Hyper Speed 7 at Zappos Buy Asics Gel Hyper Speed 7 at Road Runner Sports Buy Asics Gel Hyper Speed 7 at Kelly's Running Warehouse Buy Asics Gel Hyper Speed 7 at Charlotte Ultra Running Company

4.3 Altra Instinct‏ and Hoka Clifton

The Hoka Clifton is the best Maximalist shoe by far, combining massive cushioning with light weight. The Instinct is the same weight as the Clifton, but it offers far less cushioning. What the Instinct does offer is a shoe designed for the human foot, plus a little more padding in the upper. I would choose the Clifton every time over the Instinct, except those occasions where I didn't want to cut the toe box open. This would be in ultras where I'm walking a lot and having problems with debris getting in the openings. (That said, check out the Altra One below first.)

Altra Instinct 3.5 top	Altra Instinct 3.5 bottom	Altra Instinct 3.5 inside	Altra Instinct 3.5 outside
Hoka Clifton 2 top	Hoka Clifton 2 bottom	Hoka Clifton 2 inside	Hoka Clifton 2 outside

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 Hoka Clifton 2 at Zappos Buy Hoka Clifton 2 at Road Runner Sports Buy Hoka Clifton 2 at Kelly's Running Warehouse Buy Hoka Clifton 2 at Charlotte Ultra Running Company

4.4 Altra Instinct‏ and Asics GT 2000

I like to compare shoes against my benchmark "normal running shoe", the Asics GT 2000. The GT 2000 is heavier than the Instinct, and has slightly more cushioning, but the two shoes could not be farther apart in their use of The Science of Running Shoes. The Instinct doesn't try to interfere with your stride, or encourage a heel strike like the GT 2000. Comparing how the two shoes feel, the Instinct is like running barefoot on a well cushioned track, while the GT 2000 is like running in a wooden clog. The Instinct is a clear demonstration of what's wrong with traditional running shoes and how they should be created.

Altra Instinct 3.5 top	Altra Instinct 3.5 bottom	Altra Instinct 3.5 inside	Altra Instinct 3.5 outside
Asics GT2000 top	Asics GT2000 bottom	Asics GT2000 inside	Asics GT2000 outside

5 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
Older shoe reviews: Saucony Hattori Review, Mizuno Cursoris Review, Skechers GO Bionic 2 Review, Hoka Clifton Review, Saucony Virrata 2 Review, Brooks PureCadence 3 Review, Brooks PureConnect 3 Review, Brooks PureFlow 3 Review, Skechers GO Bionic 2 Review, New Balance 980 Review, Brooks Transcend 2 Review, Hoka Huaka Review, Patagonia EVERlong Review, Asics 33-DFA Review, Hoka Conquest Review, Saucony Cortana Review, Puma Faas 100 R Review, Saucony Fastwitch Review, Nike Free Review, Asics Gel Lyte 33 Review, Skechers GOmeb Speed Review, Skechers GOrun Ultra Road Review, Nike LunaRacer Review, Altra Paradigm Review.