Saucony Peregrine ISO Performance Review

The latest version of Saucony’s perennially popular trail shoe, the Peregrine, is the first to employ the company’s ISO fit upper, which allows the runner to customize the fit of the shoe via a series of TPU wings along the midfoot, through which the laces are threaded. You can give yourself more room at the midfoot with a tighter fit around the heel, or vice versa.

The Peregrine ISO has a full-length Pwrfoam midsole topped by a full-length 3 mm Everun midsole for cushioning and a responsive ride, and a Pwrtrac outsole with directional lugs to provide grip whether running uphill or down.

The Good

The mesh upper is reinforced, and it appears pretty sturdy; definitely sturdier than the previous version of the Peregrine, which had some durability issues.

I received the Peregrine ISO in the aqua colorway, and I love the color. They really stand out among the blah gray and black of most of my other trail shoes. The laces are somewhat stretchy and are of a length that makes sense, which seems to be the exception these days. Step-in feel is nice, though the shoe does feel a bit rigid underfoot. The tongue has elastic gussets, and the heel collar is padded.

The Bad

OK, look. Guys, I know how popular the Peregrine is. I know so many people who love this shoe. I don’t love it (you’re shocked, I’m sure). I also don’t hate it, aside from the fact that the ISO thing does not work for me at all. My longest run in this shoe was a hill repeat workout, and I wanted to test the bidirectional lug situation. The trail was really icy, and while I do think these handled that aspect better than most trail shoes would, the bidirectional thing really only works if you heel strike going downhill, which I try my best not to do.

My biggest problem, however, was that the TPU straps put a lot of pressure on a rather large seam between the tongue and the elastic gusset, and even though I readjusted several times throughout the run, I eventually had to cut my run short because it was so painful. I still have bruising right along where the seam was. I didn’t have this issue during other runs, but the 4K or so of downhill was an issue. When I tried to put these on for a run the following day, it was painful just walking around.

There’s also the weight. At 9.2 ounces, I feel like whatever responsiveness is provided by the midsole becomes sort of meaningless. “Responsive” is not a word I would use to describe the ride of this shoe. They aren’t flat, but they feel so heavy.

Saucony Peregrine ISO Conclusion

I felt some pressure to give these a positive review because they’re so popular. Maybe it’s me. Maybe lovers of prior Peregrine iterations will love these, too, or maybe there’s an issue with the ISO. Anecdotally, I spoke to one other Peregrine fan who bought a pair of the older model after trying the ISO and also having fit issues. My advice is that if you like the Peregrine, try the ISO model out before you buy.