Merrell MTL Long Sky 2 Matryx Review

Alastair explores the rugged agility and responsive design of Merrell's latest trail running shoe for mountain runners.


All opinions are our own and never influenced by brands. If you buy through links, we may earn a commission.

I’ve been out on the trails testing the Merrell Test Lab Long Sky 2 Matryx to see how these trail running shoes handle the rugged terrain of Northern California, and without giving too much away too soon – OMG, these trail running shoes are immensely good! Designed for rugged, unpredictable mountain running with frequent changes in speed, direction and elevation, the MTL Long Sky 2 Matryx provides lightweight agility and rapid responsiveness.

I can’t wait to share my experiences running in these beauties! Let’s go!

Who are the Long Sky 2 Matryx for?

Let’s start off by identifying who they’re going to be best for based on their design and effectiveness over different distances and terrain, if this sounds like the type of running you enjoy doing, or that you would like to do more of, then keep reading, otherwise head over to my best trail running shoes roundup to find a pair better suited to you and your requirements.

The Long Sky 2 Matryx are very lightweight, minimal and built for the rough and tumble of rugged terrain. These are for the scramblers, the speedsters, and anyone who thrives on sudden changes in speed, direction, and elevation. Dubbed ‘Long Sky’ for a reason, these are crafted for Skyrunning style trail running.

The MTL Skyfire 2 is Merrell’s even lighter elite trail racing shoe which also has some incredible attributes – you’ll just have to read my MTL Skyfire 2 review next to learn more about that one.

Merrell MTL Long Sky 2 Matryx Review | Trail and Kale Running Co.
Merrell MTL Long Sky 2 Matryx Review | Trail and Kale Running Co.

For those new to the term, in its basic form, Skyrunning is a thrilling high-altitude sport that starts at the base of a mountain and involves intense climbing and swift descents – many of these races are around half-marathon distance, which happens to be my personal favorite distance.

Technical specifications

  • Price: $160 at
  • Weight: 8.9 oz (252g), 15% lighter than its predecessor
  • Sizing and fit: True to size in length with a medium width
  • Upper: Matryx upper fabric combines Kevlar and high-tenacity polyamide to create a lightweight, breathability and abrasion resistant mesh.
  • Midsole Cushioning: Two part, dual density FloatPro™ Foam midsole
  • Outsole: Vibram Megagrip with 5mm lugs
  • Heel-to-Toe Drop: 4mm, for a natural foot position and trail control
  • Stack Height: Low profile with 23.5mm at the heel and 19.5mm off the ground at the toe

My performance review after real world testing in the mountains of Northern California

As a professional running shoe reviewer, I don’t believe in cutting a shoe in half or putting a Dremel sander to a shoe’s upper material 🤣 – I’m mean that’s probably the most useless way you can spend your time “reviewing” a shoe because ultimately, the true test of outdoor performance gear, is actually taking them out in the environments and putting them under the stresses that they’re actually designed to be put under – not a sterile lab with a scientist poking at their midsoles, lol.

With that said, I’ve been having so much fun experiencing the MTL Lab Long Sky 2 on our local trails, so that I can share my expertise and insights into how they perform, and whether you may enjoy them too. And damn, are these something special! Merrell Test Lab, I see you, and I’m loving your work!

It’s immediately clear these aren’t your ordinary trail running shoes, they’re designed specifically for the demanding dynamics of Skyrunning style running; they promise a blend of lightweight design and rugged durability. Over the course of several runs, including steep ascents and swift descents typical of a sky race, I put these claims to the test.

Overall the fit is noticeably secure, a crucial feature when the trail demands abrupt changes in direction and speed
Overall the fit is noticeably secure, a crucial feature when the trail demands abrupt changes in direction and speed

The moment you slip into the Long Sky 2 Matryx edition, overall the fit is noticeably secure, a crucial feature when the trail demands abrupt changes in direction and speed. This secure fit is largely due to the innovative Matryx upper, which integrates Kevlar and polyamide for a single-layer material that’s both breathable and extremely durable.

I did notice however that there is some slip in the heel lock, and unfortunately the Racers Loop Heel Lock lacing method wont work here as the tongue is short and so the laces will be placed over the top of your foot – this is best explained in my video. This very small amount of slip became a non-issue after running in them for a few kilometers – and did not affect performance in any way.

The collar and heel counter are also nicely padded as you can see in the photo below.

The collar and heel counter are also nicely padded
The collar and heel counter are also nicely padded

They feel responsive under foot, with a great amount of protection from sharp terrain, two attributes that shine as I tackle varying trails.

Here’s a closer look at that Matryx upper mesh, with extra durability in areas where it’s needed, like where your big toe wiggles for example.

A closer look at that Matryx upper mesh, with extra durability in areas where it's needed
A closer look at that Matryx upper mesh, with extra durability in areas where it’s needed

Skyrunning is as much about the climb as it is about the descent, the Long Sky 2 excels in uphill challenges. The shoe’s design seems to anticipate steep climbs, offering substantial support and traction. The Vibram Megagrip outsole, with its 5mm lugs, provides exceptional grip, allowing for confident, aggressive pushes up the hill.

Even on loose gravel and slick mud, the shoes manage to claw into the terrain, propelling me forward without slippage.

FloatPro foam midsole and a 4mm drop from heel to toe
FloatPro foam midsole and a 4mm drop from heel to toe

The FloatPro foam midsole, though less cushioned than some might prefer, offers a dual-density build that balances comfort with ground feel. This responsiveness is critical on uneven surfaces where a high degree of proprioception (sensing the ground through the shoes) is required. It ensures that each step is planted firmly and no energy is wasted.

What goes up must come down, and descending is where the Long Sky 2 truly proves itself, as you’ll see in my video review. The combination of the shoe’s low stack height and the 4mm heel-to-toe drop keeps the foot in a more natural position, enhancing stability when speed and precision are paramount.

Vibram Megagrip with aggressive 5mm lugs
Vibram Megagrip with aggressive 5mm lugs

As I navigate down steep trails, the shoes offer reassuring grip, with the 5mm deep Vibram Megagrip lugs digging into the dirt and providing the control needed to manage rapid descents safely. See below for a closer look at the lugs and how they wrap up around the toe for extra grip on steep climbs.

A closer look at the fantastic outsole
A closer look at the fantastic outsole

The breathability of the upper also comes into play here, as climbs and descents can generate a significant amount of heat inside the shoe. Despite the rigorous pace and the warm California sun beating down, my feet remain relatively cool, courtesy of the Matryx fabric’s ventilation.

While primarily designed for mountainous trails, the Long Sky 2 Matryx are versatile enough to handle flatter, more technical sections as well. On hard-packed dirt and rocky paths, the shoes perform very well. That firm, responsive midsole translates to quick, agile movements, essential when dodging rocks or jumping over roots.

However, runners looking for a plush ride on long flat stretches might find the firmness less comfortable over extended periods. In these scenarios, a shoe with a higher stack height and more cushioning, like the HOKA Speedgoat 6, might be more appropriate. See the images below to get an idea of how they differ:

After multiple runs, the durability of the Long Sky 2 is evident, the Matryx upper shows minimal wear, and the Vibram outsole looks ready for many more miles, which I am going to willingly oblige – I’m keeping these for half marathon races and fast training runs! This durability is crucial for trail shoes, which often suffer from quicker degradation due to harsh running conditions.

The Merrell Test Lab Long Sky 2 is a great choice for anyone who demands a shoe that can handle the rigorous demands of fast and light trail running.

Its design facilitates quick, agile movements and solid footing on both ascents and descents, essential for the high-intensity nature of mountain races. The shoe is lightweight, and the breathable upper does not compromise on durability, making it a reliable choice for rugged terrain.

Inside the shoe

For runners who prioritize a deep connection to the trail and a shoe that responds as fast as they do, the Long Sky 2 Matryx is undoubtedly worth considering. Whether it’s sprinting up a rocky incline or navigating a technical downhill, these shoes are designed to maximize performance where it counts.

Are they worth buying?

Are the Merrell Test Lab Long Sky 2 trail running shoes worth the $160 price tag? Absolutely. For anyone who loves the raw challenge of Skyrunning-style running, these shoes are a stellar companion. They excel in what they’re designed for: fast, high-intensity mountain races. Whether you’re powering up a steep incline or navigating a gnarly downhill, the Long Sky 2 Matryx will handle it all with finesse – and yes, they look awesome too.

If you’re planning your next sky race or just love exploring mountainous trails, the Long Sky 2 should definitely be on your radar. And while you’re at it, why not swing by our Youtube channel for more running shoe reviews and drop into our Instagram ‘@trailandkale to catch all the latest action from us as we receive new running shoes and explore new trails!

Got a specific running shoe you’d like myself or Helen to review?

Got a running shoe you’re itching for one of us to review, or need tips on conquering those sky-high climbs? Drop a comment below or hit us up on social media – let’s get the conversation going! Oh, and if you’re familiar with the Morzine area; I’d love to hear your top trail spots and coffee stops as we’re visiting in a few weeks and haven’t explored that area before 🙂

Remember, whether you’re a seasoned ultramarathoner or a weekend trail warrior, it’s all about enjoying the run. Catch you on the trails!

As the founder of Trail & Kale, and seasoned marathoner & ultrarunner, Alastair loves bringing our readers independent running shoe reviews and gear insights to help you run your best. Learn more about Trail & Kale here.


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.

New Shoe Reviews
Fresh drops from our reviewers

Nike Pegasus 41 Review: The Flying Horse...

Is the Nike Pegasus 41 still the go-to daily trainer for runners seeking a dreamy balance of cushioning, responsiveness, and durability? Well, yes... yes it is. I'm not one to keep secrets from you ;)

La Sportiva Levante Review: Toe Bumper &...

This women's-specific trail running shoe is designed for all-mountain performance and technical, rocky, terrain.

Brooks Ghost 16 Review: Updates Further Enhance...

With an improved fit, lighter design, and continued reliability, Brooks has just reaffirmed why the Ghost line is their most popular daily trainer.

Updated Roundups
Top performing gear

These Are The Best Carbon Plate Running...

Find the best carbon plate running shoes for YOU. Shoe entries are ranked in order of performance and include links to in-depth reviews

Best Brooks Running Shoes of 2024 Ranked...

Welcome to the ULTIMATE Brooks Running shoes buyer's guide, complete with reviews + rankings of the best Brooks shoes | YES, I've reviewed them all!

Best HOKA Running Shoes of 2024 Ranked...

ULTIMATE HOKA Running shoes buyer's guide, complete with reviews + rankings of the best HOKA running shoes. YES, I've reviewed them all!
Trail & Kale Running Co logo Email Newsletter

Join Our Community

Gear Reviews + Stories

Master Running Cadence To Run Faster And...

Trail & Kale's ultimate guide to improving your running cadence for a faster, safer, and more efficient running technique.

Father’s Day Gifts For Dads That Run...

The most thoughtful gift ideas for dads who run, whether it's his birthday, Father's Day or another special occasion, there's a cool gift for your run-loving dad on this list.

LEKI Ultratrail FX.One Trail Running Poles Review

Having tested them thoroughly in the mountains of Northern California, Alastair shares how these premium running poles improve trail performance

Training Plans
5K, 10K, Half Marathon, Marathon, Ultramarathons