Merrell MTL Long Sky 2 trail running shoes review: lock in for technical trails

Merrell MTL Long Sky 2 trail running shoes: first impressions

Merrell describes its latest trail running shoes as ready-for-anything, and after testing them out, we’d have to agree. These trail runners are lightweight for when you want to go fast and far and with an internal bootie that pulls on like a sock, you get an instant locked-in fit without having to retie your laces. Easy to pull on, the snug fit around the cuff is balanced with a roominess around the toe box which adds to the light, airy feel of these shoes.

Breathable mesh uppers with a TPU overlay manage to be durable and keep your feet cool when you’re out in hot weather, plus they’re quick drying for when you’re splashing through puddles. Once you hit uneven, rocky terrain, you’ll really appreciate the stability provided by the low 4mm drop combined with 5mm lugs on the MegaGrip soles, which hold up even in slick conditions. They’re not waterproof, but with gaiter attachments you can easily protect your feet in a deluge. 

The FloatPro Foam midsole strikes a nice balance between cushioning and a decent trail feel. These aren’t big and bouncy for super long runs, nor are they barefoot and minimal – they’re great for handling technical terrain and mixed conditions with confidence.

Merrell MTL Long Sky 2 trail running shoes: in the field

These shoes arrived just as the uppers on my last pair of trail runners separated from the sole, so I was eagerly anticipating them. I’ve been hiking in Merrell shoes for a couple of years and really like their handling on the trails, waterproofing and robustness, so I had high hopes for their running shoes and I have not been disappointed.

I will admit I was a little skeptical of the internal bootie which gives the shoes a sock-like construction. I have a pair of hiking shoes with this same construction and with high arches, I find them quite hard to pull on. However, these ones slip on fairly easily and once on, I get a tight, firm, locked-in heel without having to tie a heel lock, which is great for running over rocky terrain.

Once I headed out in these, there were two things I noticed straight away that I really like. The first is that they have a really perceptibly airy feel thanks in part to the breathable uppers, but mostly due to the extra room in the toe box. My previous running shoes have tended to be a bit snugger around the toes, which can actually impact my ability to use my toes and move optimally, and I was surprised that these have so much room while being so snug around the cuff. Anyway, the result is that they feel really comfortable, especially on hot days. They also have a little reinforcement around the toes for bashing into rocks (or long talons).

The other thing I really like is the FloatPro Foam midsole, which I found strikes a perfect balance between cushioning and trail feel. I’ve been running in big, bouncy shoes for the past two years which felt very cushy, but meant I didn’t get much sensation of the ground beneath my feet, and while I don’t like a lot of trail feel, I appreciate getting just a little more with these. Initially, I thought they wouldn't be as comfortable as a result but I definitely prefer them. The low drop and good lugs means I feel really stable, even when I’m on tough terrain.

I’ve had these out in a few downpours and, no surprise, the Vibram soles definitely deliver the mega grip they promise. The uppers aren’t waterproof (which helps with breathability) but they dry quickly and though I haven’t tried them out, they come with hooks in the heel for your gaiters if you’re out for a long distance dash in a deluge. 

Overall, I think Merrell has done a fantastic job of combining just about everything I’d want in a trail runner, from weight and breathability to stability and comfort, for a really technical shoe.

Here’s how they performed:

Sizing and fit

These fit true to size and are snug around the cuff, but roomy around the mid foot and toe box. They might be too wide for narrow feet.

Comfort

Locked-in fit prevents rubbing and provides a snug fit, while the mid-sole gives enough cushion for protection against rocky trails without impact trail feel. Roomy toe box gives a light, airy feel.

Breathability

Breathable mesh uppers are quick drying and offer plenty of ventilation.

Durability

Only time can truly tell, but all signs point towards a pretty durable shoe with good construction and TPU lined uppers.

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