361 Merrow Review: The Lightest 5K and 10K Racing Shoe of the Year

Introduction

Some racing shoes arrive quietly and turn out to be the most exciting release of the year. That is exactly the case with the 361 Merrow. It is not heavily advertised, but it delivers something the racing category has been missing: a truly ultralight shoe that still carries a genuine super shoe bounce underfoot. At just 4.3 oz (122 g) for a men’s size 10, it is the lightest racing shoe currently available, lighter than most track spikes, and it manages to feel fun in a way few modern racers do. After around 20 miles, it has earned its place as a top pick for 5K and 10K racing.

Who This Shoe Is For

The Merrow is built for short, fast efforts. It shines over 5K and 10K distances, works well for tempo runs, and turns over beautifully on the track and during hill repeats. It feels like a super track spike: quick to roll, aggressive underfoot, and rewarding the moment you pick up the pace. This is not a marathon shoe. The heel does not feel stable enough for long miles, and most runners will want more shoe for anything beyond a half marathon at the absolute limit.

Landing at the forefoot is where the design really clicks. Transitions feel best when you stay up front, and runners who like to get on their toes will feel at home immediately. If you have midfoot stability issues, look elsewhere: the Pebax foam compresses quite a bit and the narrow midfoot offers little correction.

Weight and Midsole: Super Shoe Feel at 4.3 oz

The headline number is 122 g in a men’s size 10, which is remarkable. Outside of the Adidas Adizero Adios Pro Evo 1, nothing in this space is lighter, and the Merrow manages it at $220 rather than $500. The midsole is a full-length Pebax construction with a full-length carbon fiber plate, and the result is a genuinely bouncy, energetic ride. Despite how thin and light the shoe is, there is real cushioning underfoot, with a pleasant rockered feel and a bevel at the heel that smooths landings. The stack height is tall, with self-measured estimates suggesting around 41.5 mm at the heel and 35 mm at the forefoot for roughly a 5 to 6 mm drop, though official figures are scarce. The offset feels moderate in practice, and the height is more than offset by how light the shoe is.

Durability: Lightweight Comes With Trade-offs

This is where caution is warranted. The Merrow carries a large amount of exposed Pebax midsole, and after 20 miles there is already some digging into the foam and minor lifting near the forefoot edge. That is not terrible for a shoe this light, but it is not great either. Runners with a heavier or harder stride should not expect long-term longevity.

One honest piece of feedback for 361: a fuller outsole would improve durability without adding much weight. Until then, treat this as a race day shoe. The good news is that it has held up better than some options costing twice as much, and lighter runners should be fine.

Ride and Handling: Fast Transitions and Track-Like Feel

On the track, the Merrow is a revelation. It turns over with almost no effort, grips well on track and road surfaces, and rewards aggressive pacing. Tempo runs feel wonderful once you settle into a rhythm, and the shoe has a habit of making everything else feel heavier afterwards. It genuinely evokes classic ultralight racers like the Mizuno Wave Universe, but with far more cushioning.

The forefoot is the cushioned, centered sweet spot, with tall sidewalls on both sides, especially medially, that help offset the narrow heel and keep you centered when rolling through the front of the shoe. The midfoot is very narrow and the heel is narrow too, while the forefoot runs a bit wider. One small caveat: the prominent sidewalls in the forefoot may cause blisters for runners sensitive to pressure there.

Fit and Upper: Snug, Minimal, Track-Spike-Like

The fit is snug and anatomical, holding the foot very close without being a toe cruncher. The forefoot is straight on the medial side and rounded elsewhere, with a small amount of volume that keeps the big toe comfortable. There is not a lot of room overall, so this is not the shoe for wide-footed runners.

The upper is so light that putting the shoe on requires some care, but once laced it locks down with minimal effort. The heel area has a touch of added structure, not quite a counter, that holds the back of the foot nicely with some padding. Overall it feels like a track spike with a lot more foam underfoot.

Buying Advice

At $220, the Merrow sits in an interesting position: expensive by everyday standards, yet a strong value against the handful of shoes it competes with at this weight. If you race 5K and 10K distances and want super shoe bounce at record-setting weight, it is one of the best options available. Save it for race day and fast workouts, keep it off trails, rocks, and soft surfaces, and it will reward you every time you lace it up.

Conclusion

The 361 Merrow is the most exciting short-distance racing shoe of its year: insanely light, genuinely bouncy, and fun in a way modern racing shoes had lost. Durability is the only real question mark, but for runners who treat it as a race day weapon, it is hard to beat.