With ‘skeleton-inspired lugs’ and a quite flexible sole, the Agility Peak Flex trail running shoe excels on rocky, slick, or muddy trails. We tested them more than 100 miles for this initial review.
On a narrow muddy ridge, I pushed past the urge to walk. Rain pounded down as I ran along a near-vertical drop. Now would not be a good time to slip and fall. I didn’t.
Merrell touts its newest trail runner as supremely flexible. Grooves cut in both the top and bottom of the midsole let the shoe bend up or down. A stiff heel lock keeps feet in place. A rock plate protects from hard edges.
In testing, we had a hard time noticing anything out of the ordinary under foot. Most shoes flex, and these do too. But this is a good shoe that delivers as a protective trail runner.
Aggressive lugs follow the lines of long bones in the foot on the outsole. The “skeleton-inspired” lugs grip soft earth or rock, and provide excellent traction.
Review: Merrell Agility Peak Flex
The shoe consists of a mesh and TPU upper and a thick sole with a 6 mm drop (33.25/27.25mm heel/toe). The upper does decently well to keep water and debris out of the shoe. But it is not waterproof.
Intended for off-road running, the shoe also cushions nicely on harder surfaces and paved terrain. It’s average weight for a trail shoe, 11 ounces, but doesn’t feel bulky.
The unique lacing system adapts as your foot shifts within the shoe. The green strands stretch when tightening and, as your foot adjusts to its natural position, they relax and bend with it.
This makes it hard to tighten certain parts of the shoe, though. It tends to even out the tension along the laces throughout the upper. However, I enjoyed the fit, and my foot sat comfortably within the shoe with no pressure points as I ran.
Where To Test
Optimal running spots for the Agility Peak Flex are dirty, wild trails. The big tread and modest weight should make them a fit for big mountain trails with rocks, roots, or groomed-out dirt goodness.
They are OK on pavement, as the big stack height dampened the harsh paved impact. However, the shoes yearn for uneven terrain.
Boring But Important
Flexible trail running shoes are nothing new. Each can flex sideways and lengthwise, some more than others. These were notably flexible, but nothing out of the ordinary.
The 6 mm drop results from a 33.25 mm heel to 27.25 mm footbed. Each shoe weighs 11 ounces.
These fit true but a little narrow. They fit my narrow feet with medium arches well. Another editor with wider feet found they were a little tight for the size. Those with medium or narrow feet will fit better.
When on muddy terrain, It felt like the shoe expanded and flexed under my foot, increasing surface area and contact with the ground for superior grip. A weird phenomenon to be sure, but one that left me confident on muddy ground.
Who Should Buy It
Those who like a variety of trails should consider the Agility Peak Flex from Merrell. While not waterproof, they do handle well on dusty, rocky tracks in addition to muddy, grassy, and rooty trails.