What?! A true stability shoe that’s this light, low to the ground and energetic? Pick up the Impulse and you’ll be in disbelief too, at least until you start running in it. With the creation of the Impulse, Altra has developed a featherweight and uber-flexible, performance-oriented training/racing flat that serves up a smooth, stable and absolutely sublime ride.

The shoe incorporates Altra’s three-point StabiliPod stability system—three firmer foam pods spread across the midsole/outsole, combined with a cantilevered varus wedge built into the midsole and a wider-than-typical footprint, help offset overpronation, while the foot-shaped forefoot gives toes plenty of room to splay for maximal forefoot energy transmission. The midsole foam is a combination of a lightweight/absorbent EVA foam and a more energetic responsive foam Altra calls A-Bound. (The Impulse is lighter, softer and slightly lower than Altra’s Provision 2.0 stability shoe and perhaps more similar to Altra’s neutral-oriented Torin 2.0 and Instinct/Intuition 3.0 in how it runs.) It also features an asymmetrical lacing pattern that, although looks completely unique, our wear-testers were unanimous in their approval of the snugged-down fit and feet of this shoe.

As with every Altra shoe, the Impulse has a flat or “zero-drop” profile, meaning the heel is the same height off the ground as the forefoot. The thinking is that if a foot is positioned naturally without an elevated heel (as it is when it’s barefoot on the ground), it can function naturally through the entire gait cycle. If you’re used to running in shoes with a low drop or flat profile, this lightweight, performance-oriented stability shoe with a low-to-the-ground feeling might be an ideal race-day tool for your quiver. “This shoe was a real surprise,” says wear-tester Chris Ball. “The design is entirely different than what I typically run in, but I really liked how fast and light it feels and runs.”

This is the shoe for you if … you’re an Altra and/or zero-drop devotee and want a super-light performance shoe for fast training and racing.

Price: $120
Weights: 8.6 oz. (men’s size 9); 6.5 oz. (women’s size 7)
Heel-Toe Offset: 0mm; 23mm (heel), 23mm (forefoot)
Info: AltraRunning.com

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