Montane Trailblazer LT 20 running backpack review: super light storage for long trail runs

This body-hugging, lightweight design provides tons of gear storage for when you want to move light and fast

Montane Trailblazer LT 20
(Image: © Julia Clarke)

Advnture Verdict

This ultralight running backpack fits great and holds tons of gear for fastpacking adventures, but is unnecessarily complicated to get the hang of.


  • +

    Super light

  • +

    Body hugging design stays in place

  • +

    Fully waterproof

  • +

    Loads of storage

  • +

    Pole attachments

  • +

    Hydration bladder compatible


  • -

    Too many dangling straps

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    Unnecessarily complicated

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    Hydration bladder slot is too small

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    Shoulder straps may not fit flush (multiple sizes may be needed)

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    Shoulder strap pockets not large enough for all phones

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Montane Trailblazer LT 20 running backpack: first impressions

This running backpack combines ultralight weight with a body-hugging design, meaning you can run far and fast without your gear bouncing around or slowing you down. Montane has cut way down your typical zips and buckles to get this pack weight down to just 300g, and in their place has used innovative (if initially complicated) solutions for adjusting the carrying straps and sealing pockets.

The roll-top opening makes way for 20 liters of space within the main body that is complemented by four extra pockets. Once you fit it to your body, it stays in place even on technical trails, and the mesh backing and straps don't get you overly sweaty on hot, humid days.


• List price: $130 (US) / £100 (UK)
• Weight: 10.6oz / 0.3kg
• Materials: Main: 100% nylon; back pad / shoulder straps / hip fins: 100% polyester
• Hydration bladder compatible: Yes
• Gear capacity: 20L
• Colors: Orion blue
Compatibility: Hiking, trail running, fastpacking 

This backpack features taped seams for a fully waterproof design, meaning you can trust that your sleep system is kept dry on fastpacking adventures. Wraparound pockets plus small pockets on the shoulder straps mean you can keep running gels and other snacks close, although none are large enough for your phone, and it’s hydration bladder compatible so you can carry all the water you need without foregoing space for your waterproof jacket

The bungee cord design works as both compression, to keep you more aerodynamic, and also holds extra gear along with pole attachments in the shoulder straps for those of you who run with poles. This lightweight and comfortable running backpack is competitively priced compared to other running backpacks we’ve tested, and features an innovative – if a little complicated – design that you’ll like once you get the hang of.

Montane Trailblazer LT 20 running backpack: in the field

Montane Trailblazer LT 20 on the trail

This backpack features taped seams for a fully waterproof design, meaning you can trust that your sleep system is kept dry on fastpacking adventures (Image credit: Julia Clarke)

I have a master’s degree and I like to think that I’m smarter than a backpack, but this one had me thinking otherwise, and not for all the right reasons. Montane has come up with some innovative solutions for fastening and adjusting the various straps on this running backpack that help shed weight, but I found them quite difficult to figure out, and therefore it actually took me a few weeks to even get out the door with it. 

Every so often I’d put it on, but I couldn’t quite figure out how to secure the roll top and I seemed to end up with loads of loose straps everywhere, so I’d take it back off and just go for a run. In the end, I ended up scrolling through pictures and a short video on Montane’s website to try to figure it all out and, while I made some progress, I’m pretty sure there are details I’m still missing. What I’d really like is an instructional video. All that’s to say, I didn’t get off to a great start with this backpack, and perhaps I’m the problem – maybe I’m just way behind in running backpack technology – but once I did finally get out the door with it, things improved.

What I love about this running backpack: it’s crazy lightweight, comfortable, stays in place when I’m moving fast, and has tons of storage. Obviously, it’s going to get heavier once you put gear in it, but a starting weight of 300g means you’re not going to question whether or not to use it if you’re going on a run with gear and lots of water.

Even though I don’t think it fits me superbly, it still feels great on. I’ve had no rubbing or chafing from it, the mesh back and shoulder straps mean I don’t get too sweaty and I’ve had it out in some pretty humid conditions, and the body-hugging design really does stay in place when it’s packed with gear. Big bonus.

Montane Trailblazer LT 20

I’ve had it out in some pretty humid conditions, and the body-hugging design really does stay in place when it’s packed with gear (Image credit: Julia Clarke)

It really does have a lot of storage for such a small pack. The main body expands (and compresses, thanks to the bungee cords) so you can pack it full of overnight gear and it has wraparound expandable mesh pockets that are reasonably easy to reach, and small zip pockets on the shoulder straps for gear you want close. These just fit my phone, but they’re not quite big enough for a larger iPhone, unfortunately. There are also loops to hold running poles which work quite well once you figure out what and where they are (I had to watch a promotional video).

It is hydration bladder compatible, but the opening for the bladder isn’t all that big, so I had trouble getting mine in once it was filled with water and ended up putting it in empty then trying to fill it, which is a bit of a nuisance.

As I’ve mentioned, I seem to have loads of loose straps everywhere with this pack that don’t show up on promotional photos. I’m not sure if they’re just tucked in or if I’m missing something, but they’re a bit annoying when I’m running along an overgrown single track. Also, once I’ve fastened the waist harness and chest harness, I find that the shoulder straps don’t sit flush to my body. I’m 5’4” and not a particularly unusually dimensioned person, so again, I’m not sure if I’m missing some adjustment strategy or if Montane could do with making different versions for different torso lengths, but I will say that this doesn’t seem to impact its performance.

If you’re a long distance trail runner or fastpacker, I really think you will love the weight, fit and storage this backpack provides, once you figure out how to use it.

Comfort and fit

This backpack is really comfortable on, even when it doesn’t fit properly. There is no rubbing or chafing and it stays in place and doesn’t get you too sweaty. It’s very adjustable, but I found that the shoulder straps aren’t flush to my body and I might do better with it in a smaller size. 

Close up of the straps on the Montane Trailblazer LT 20

The shoulder straps aren’t flush to my body and I might need it in a smaller size (Image credit: Julia Clarke)

Features and storage

Waist and chest straps secure it to your body. Pole carrying straps, four accessible pockets plus a large, roll-top storage compartment fits loads of gear and a separate compartment holds your hydration bladder (though the slot for the bladder is too small).


Completely waterproof with taped seams.

Ease of use

Straps and buckles are a bit complicated to figure out initially.

Julia Clarke

Julia Clarke is a staff writer for and the author of the book Restorative Yoga for Beginners. She loves to explore mountains on foot, bike, skis and belay and then recover on the the yoga mat. Julia graduated with a degree in journalism in 2004 and spent eight years working as a radio presenter in Kansas City, Vermont, Boston and New York City before discovering the joys of the Rocky Mountains. She then detoured west to Colorado and enjoyed 11 years teaching yoga in Vail before returning to her hometown of Glasgow, Scotland in 2020 to focus on family and writing.