Merrell Agility Peak 6 Initial Review

In 2023 I feel head over heels for the Agility Peak 5: a high stack trail running shoe from Merrell with rock solid grip that performed well on anything from a fast 5k to an ultra marathon.

We've had a shaky relationship: the high drop (which feels much higher than the reported 6mm) led to a lot of instability for me, including some knee pain after using them for a few years, but they also got across the line of my first 100 miler, and helped me beat my nemesis race The EDDUM in a time I'm damn proud of.

Late 2025 they announced the successor would be coming out early 2026 and I couldn't wait. Would they change the drop? Would they fix the upper durability? Would they get that fit locked down better.

In fact the fit really was the main downside for the 5s, they were generously sized but that lead to a bit too much movement inside the shoe, especially on descents.

Along comes 2026, I start seeing some early reviews whilst waiting for mine to arrive, and I hear something that worries me: "They are now based on the Skyfire last". I'm familiar with the Skyfires: a technical low stack mountain racing shoe from Merrell that is mean to have great lock down, but also fits small and narrow with most reviews recommending sizing up.

Will the new shoe size differently? Will it be more narrow? Will this kill my love of the shoe? A box arrived on my doorstep and I guess we'll find out.

Features

In terms of technical specs very little has changed on the Agility Peak 6s, which is great news as the 5s were a rock solid base to work from, we have:

• 32mm at the heel and 26mm at the forefoot for a 6mm drop
  • I believe Merrell don't count the lugs in this so the functional stack height is 37mm to 31mm
  • The Agility Peaks 5 reportedly had a higher drop than advertised too, so be aware that may be the case here as well
• A stronger, more durable upper this time
• The same gusseted tongue, fairly thin but the laces cause no irritation
• A more structured heel counter to hold your heel better
• The same FloatPro midsole that lasts well after hundreds of km
• 5mm Vibram Megagrip outsole with Traction Lug (the little nobbly bits on the lugs that are meant to help with grip further)
• Weighs 270g

Fit and Feel

I'm not going to lie: on putting these on I immediately knew I was going to have issues.

The fit is a much slimmer profile that the 5s, a more racey, traditional fit that you'd expect from a Nike or Hoka.

The length is true to size I'd say, however the toe box is slimmer. If you have a wide forefoot I'd have said the AP5s were a good pick, but the AP6s no longer are.

It feels closer to Merrell's MTL Adapt and Skyfire fits now, rather than the Longsky 2 wider forgiving toe box.

On the plus side, for folks that found that toe box too wide and fit too sloppy, Merrell have fixed that here: the shoes lockdown much better, the heel holds well especially with a heel lock, and in general it's a more precise fit.

First Run

One thing I noticed quickly was these feel much firmer underfoot, less of that soft bounce of a fresh pair of AP5s. From other reviews I've heard the midsole softens a little with time, but out of the box they are stiff.

Definitely felt that better locked down fit.

However on the first downhill descent my big toes were immediately unhappy, feeling the edge of that slimmer toe box. After a pretty short relaxed run my toes were already starting to complain.

Cinching the upper down helped a little, and to be fair I could tie the laces pretty tight without discomfort, but didn't solve it completely.

Grip wise it's exactly the same, solid amazing grip through mud.

Drop wise they feel exactly the same as the Agility Peak 5s, which is to say they feel higher drop than 6mm for sure.

I did feel that firmer midsole wasn't giving as much oomph on hill climbs as the previous version did, though again this may improve with some breaking in.

The firmness and new grooves cut into the midsole do mean a better ground feel. I believe this would improve stability despite them being a high stack shoe.

Final Thoughts

I believe this will be a divisive update for many lovers of the Agility Peak 5s. Some folks are going to love the more dialled in fit, the firmer ride with more ground feel, and the improved durability. Some folks will find these too slim and constrictive now, or too firm underfoot.

For me, there won't be a full review of the Agility Peak 6s, as they are on their way back to Merrell for a refund. It's a real shame, I can see what Merrell were aiming for here, and time will tell if it was a popular decision. For me I'm looking elsewhere