Saucony Switchback ISO trail shoe
photo: Doug Hay

Saucony Switchback ISO Review: 100 Mile Rundown

Saucony's Switchback ISO trail running shoe uses fancy tech to deliver a smoothly-cushioned, light and fast ride with a secure, comfortable fit.

Saucony Switchback ISO trail shoe
Doug Hay

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The Rundown

Our review: If you’re looking for a fast, light trail shoe you can rely on for being responsive, secure and durable day after day, check out the Switchback ISO.

Stack Height:

According to Saucony, the new Switchback ISO was born after test runners kept taking the Freedom ISO, with its full-length EVERUN midsole, to the trails. In other words, Saucony was smart enough to take an idea they knew already worked on the road, and transform it into a trail shoe.

What they ended up with is a slick, light, minimal shoe with lots of buzz words and shoe technology. Take that EVERUN midsole, for example, or the PWRTRAC outsole, covering the bottom of the shoe with countless tiny lugs. Or the Boa lacing system and ISOFIT tongue design.

Confused yet? I was too.

See, when I see made-up shoe company words touted as if I’m supposed to know what the heck they’re talking about, I tend to roll my eyes and skip ahead. But sometimes, all those random letters actually turns into a product I’m excited about. The Switchback ISO is one of those times.

Saucony Switchback ISO trail shoe
photo: Doug Hay

The Specs

9.8 oz. (M) 8.8 oz. (W)
4 mm
22.5 mm/18.5 mm
full-length EVERUN
dual-density, grippy and tacky PWRTRAC rubber
ISOFIT dynamic upper with BOA lacing system

100 Miles In: The Review

The first thing that jumped out at me when I saw the Switchback ISO from Saucony was the Boa lacing system, so let’s start there. Boa’s unique turn-to-tighten lacing system has become a standard on snowboarding boots and cycling shoes, but when I saw it on a pair of trail shoes, what came to mind was, “no way those are going to hold up through trail mud.”

But as it turns out, they’re pretty amazing. The Boa system combined with Saucony’s ISOFIT technology (basically, a fancy way to say the thin tongue connects all the way down to the sole to give you a glove-like feel, with isolated “fingers” securing the outer saddle) locks your foot in place perfectly, with no high-pressure spots or fear of sliding around.

Saucony Switchback ISO trail shoe with Boa lacing
photo: Doug Hay

I did find the best fit came about a mile into the run when everything settled and I had tightened them down slightly, but even after long, 3-4 hour trips in the mountains, I could count on never having to tighten those laces again.

Moving on to the upper, it’s composed of a nice mix of breathable mesh and protection around the toebox. It drains fairly well (although it does tend to have the dreaded squeak for the first few minutes after it gets wet), and is rugged enough to show few signs of wear well after 100 miles.

But I think where the shoe shines most is with the EVERUN midsole. For such a thin midsole, it has a smooth, cushioned ride while also providing the ground feel and flexibility most of us want on the trail. Saucony claims the technology is bouncy, providing stronger take-offs. Oddly enough, it really does feel that way throughout both short and long runs.

Saucony Switchback ISO trail shoe PWRTRAC outsole
photo: Doug Hay

The PWRTRAC outsole (I’m not even going to pretend to know what that means, although the marketing material says it “combines a firmer center footprint with a softer, tackier perimeter for traction”) is made up of what’s easily a few hundred tiny lugs lining the bottom of your shoe, each in a V shape to help latch on to the trail with every stride. One thing that really stood out here is that because they are rather small and low profile, I never found myself catching a lug on a root or rock like I sometimes do in shoes with deep Vibram-style outsoles.

There’s the Rub

For the first time since reviewing shoes for PodiumRunner, there’s actually not much negative I can say about these shoes. They’ve easily become a staple in my rotation. But I do have a few potential concerns:

The first is the outsole. While there are many things I like about Saucony’s approach, in wet or muddy conditions, they didn’t provide the level of confidence I expect from a trail shoe. Something to consider when choosing a shoe for a wet day.

Saucony Switchback ISO trail shoe
photo: Doug Hay

The second concern is wear on the inside top lace loop. I, like many other runners I know, tend to quickly develop wear from rubbing right around the highest point of the inside (arch side) edge of the shoe. Typically this isn’t a problem, but for the Swichback ISOs, the wear falls directly on the top lace loop—a loop that, if it were to break, would completely ruin the lacing system since there are no extra eyelets or places to secure the lace. A break like that would be pretty catastrophic if out on a mountain long run. Note: my pair didn’t break over 100 miles, but the wear was a concern.


There’s no hiding it, these shoes have a minimal, fast feel. The 4mm heel-to-toe drop and low stack height, combined with a super light and flexible ride, provides great connection to the trail and a very natural stride.

The Boa lacing system locks in your foot beautifully, virtually eliminating the fear of a lace coming undone or loose over time.

Saucony Switchback ISO
photo: Doug Hay

And all that made-up word technology? Here, it actually produces results: EVERUN, ISOFIT, PWRTRAC produced a smooth ride, comfortable fit and secure grip on the trail.

If you’re looking for a fast, light trail shoe you can rely on for being responsive and durable day after day, check out the Switchback ISO by Saucony.

Doug Hay is a trail and ultra runner, father, and vegetable lover from Black Mountain, NC. Find him at Rock Creek Runner and as the co-host of No Meat Athlete Radio.


From PodiumRunner