Facts

Update: Altra Instinct 4.5
Terrain: Road
Arch support: Neutral
Weight: Men: 8.1oz | Women: 6.5oz
Heel to toe drop: Men: 0mm | Women: 0mm
Pronation: Neutral Pronation
Arch type: High arch
Material: Vegan
Strike Pattern: Forefoot strike
Distance: Competition
Heel height: Men: 24mm | Women: 24mm
Forefoot height: Men: 24mm | Women: 24mm
Brand: Altra
Type: Low drop | Zero drop
Width: Men: Normal | Women: Normal
Price: $110
Colorways: Black
Size
Small True to size Large
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Expert Reviews

Experts are runners, who post reviews at youtube, directly at RunRepeat or at their own websites. Each expert is categorized from level 1 to level 5 based on expertise. See stats on expert reviews and how we calculate scores here.

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82 / 100 based on 12 expert reviews

  • 90 / 100 | Running Into Myself | Level 2 expert

    It made a more nice snug fit. I appreciated that. The toes can still splay.

  • 88 / 100 | Happy Healthy Vegan | | Level 2 expert

    They have a little more cushioning, which really is awesome. Like I side for a longer runs,now I can go and do the distance runs.

  • 80 / 100 | Runner's World | Level 5 expert

    This small update to Altra’s original model tweaked the midsole density to bring it back to the feel of the popular first version, and improved the fit of the upper, giving it more toe height, a softer, foot-hugging feel, refined overlays, and an attractive toe swirl that gives the foot-shaped forefoot a more mainstream look. 

  • 74 / 100 | Fellrnr | Level 5 expert

    The Instinct is too firmly cushioned for its weight, with similar levels of cushioning to shoes that are much lighter. 

  • 86 / 100 | Triathlete | | Level 4 expert

    "The result is a lightweight, smooth-riding shoe that is versatile enough to be durable and protective for logging long training miles but responsive and agile enough for shorter interval workouts and tempo runs.
    "

  • 80 / 100 | Feed the Habit | | Level 3 expert

    Despite the design tweaks, there aren’t any major surprises in these update; if you liked previous versions of the Instinct or Intuition, these will continue to be a favorite. 

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  • The lacing system in the Instinct 3.5 has been redesigned. The Instinct 3.0 had a lacing system that’s too limited and tightly woven. Now, this version gives the laces a wider space between each other, making sure that most of the topside of the foot is covered. The crisscrossing of the laces even extends near the forefoot area of the shoe, making it cover more surface area.
  • The mid-foot area has been designed to have a medium volume, but it’s a bit snugger this time around. The upper unit hugs the foot well, but it doesn’t make the fit too tight or too restrictive.
  • The FootPod Outsole still offers natural flexibility, but the material used in this outer layer is firmer and more resilient against wear and abrasion. The entire sole unit still follows the natural foot shape design that’s prevalent in Altra shoes.
  • This running shoe from Altra is easier to break in, but firmer than the previous iteration. Improved cushioning systems make sure that the platform is both resistant to breakdown and still efficient in flexible & responsive underfoot cushioning.

The Instinct 3.5 fits half-a-size smaller than the regular sizing scheme. It is advised to buy this model ½ size above the standard choice. The medium-width of the heel and mid-foot areas make the fit snug and secure, while the wider forefoot area allows natural toe splaying.


The FootPod outsole, which is the same as the Altra Instinct 4.5, was designed to mimic the natural shape of the human foot. Having such a design provides runners with a more natural ride that’s balanced and stable. Natural flexibility, freedom of movement and responsiveness are the selling points of this foot-shaped outer sole.


The A-Bound is a mid-sole compound that’s made from recycled materials. It’s environmentally friendly, but very sturdy. It protects the foot from impact and discomfort when running.

Dual-layer EVA foam is a unit that offers shock attenuation, springiness and responsive underfoot support. It’s a high quality material that doesn’t easily wear off or lose structural integrity. Runners can expect a well-protected, highly efficient ride with this in the platform.

The Natural Ride System encourages natural movement of the foot by following the shape of the foot. The forefoot area is more spacious and the rear section is snugger.

The zero-drop system makes sure that the runner achieves balance, especially when transitioning from the heel to the toe. Landing the foot on the ground ensures equal distribution of impact protection, energy and natural performance.


The Quick Dry Air Mesh provides breathable support to the runner. It’s lightweight and flexible, and it has moisture-wicking capabilities while further enhances the overall comfort.

The Heel Claw construction makes sure that the rear section of the foot stays locked down and secure. It makes it easier for runners to prevent accidental slips and shoe-removals when performing.

Next-to-foot comfort is afforded by the seamless design of the upper unit. It’s an efficient design that gets rid of irritation and discomfort when wearing the shoe. Having such a comfortable inner construction allows runners to wear the Altra Instinct 3.5 even without socks.

The 5mm-thick insoles add more cushioning. Because this shoe has a low-profile design and because it has a zero-drop platform, the additional layer helps to make the foot more comfortable even when running for longer periods of time.

Comparison