Reviews You Can Rely On

Mammut Alnasca Review

A great lightweight harness for gym climbing or sport cragging
mammut alnasca climbing harness women review
Credit: Mammut
Top Pick Award
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Price:  $120 List
Manufacturer:   Mammut
By Jane Jackson ⋅ Senior Review Editor  ⋅  May 11, 2020
  • Hanging Comfort - 30% 7.0
  • Standing Comfort - 25% 9.0
  • Features - 20% 7.0
  • Versatility - 15% 5.0
  • Adjustability - 10% 5.0

Our Verdict

The Mammut Alnasca gets our Top Pick for Gym Climbing for its simplistic design, breathable waistband and leg loops, and lightweight feel. It provides the bare essentials needed to safely go climbing, but in a slimmed-down package — ideal for the gym. If you don't need to carry a bunch of quickdraws, cams, or personal gear, this harness is very comfortable. It's not bad to hang in, though we wouldn't want to wear it on a big wall. Sometimes we forgot we even had the Alnasca on and ended up walking around in it all day without hardly noticing it.
Excellent standing comfort
Relatively good hanging comfort
Tiny belay loop
Lacks versatility

Our Analysis and Test Results

A combination of Mammut's split-webbing design and TPU-coated mesh fabric make the Alnasca both lightweight and comfortable. The ergonomically shaped waistband is highly breathable — great for a sweaty, crowded gym session, and comfortable to hang in. With two solid gear loops in the front and two flexible loops behind, the Anasca doesn't have a ton of room for gear, but more than enough for a gym session.

The downside to this super-light harness is its limited versatility. The Alnasca works great for sport climbing and gym climbing but is too flimsy to feel comfortable wearing on burlier, longer outings. The gear loops are fairly small too, limiting the amount of gear you can carry on it. The leg loops don't adjust and have a small amount of elastic, so the range of adjustability on this one is also relatively limited.

Performance Comparison

mammut alnasca climbing harness women review - the lightweight alnasca is our top pick for the gym - slim and easy...
The lightweight Alnasca is our Top Pick for the gym - slim and easy to use!
Credit: Eric Bissell

Standing Comfort

Weighing in at just a hair over 11 ounces for a size medium, the Alnasca is one of the lightest harnesses in this review. For your lead burns, gym days, or climbing trips to locales with mostly fixed draws, the Alnasca is the ticket. We found this harness to be incredibly comfortable to wear around — practically forgetting it was on! This is the type of harness you can put on at the beginning of a gym session, and still be wearing as you chat with friends hours later — when you realize you're still lingering at the gym.

mammut alnasca climbing harness women review - the mesh panels on the leg loops and waistband make this harness...
The mesh panels on the leg loops and waistband make this harness very breathable in a sometimes stuffy gym.
Credit: Eric Bissell

The mesh panels on the leg loops and waistband make it breathable and thin. Plus, the other materials used make this harness feel sleek against the body when walking or moving around.

Hanging Comfort

In terms of hanging comfort, it makes sense that the Alnasca falls a little bit short, in comparison to harnesses designed for multi-pitch climbing and trad climbing. There is simply less padding on this model since its purpose is to be lightweight and sleek. That said, the ergonomic, thoughtfully designed shape of the leg loops and waistband disperse weight well and make for a comfortable hang when working your project. We also didn't mind giving long catches in this harness, as the wide backs of the leg loops spread the load evenly, without digging in anywhere.

mammut alnasca climbing harness women review - moments before testing the hanging comfort of the alnasca on another...
Moments before testing the hanging comfort of the Alnasca on another pumpy gym route.
Credit: Eric Bissell

Discipline-Specific Features

This harness is designed specifically for sport climbing and gym climbing. It is lightweight, breathable, comfortable to walk around in, and has minimal features. The sport climbing specific features are mainly the thin leg loops and the small gear loops. The front two gear loops are rigid, while the back two are flexible to cut weight. We didn't mind this set up for shorter climbs since we mostly racked all of our gear on the front loops anyways.

Another small hang-up we had with the gear loops is the fact that the loops are attached to the top of the harness waistband. This means that there is less than an inch of clearance between the gear loop and the waistband, making it hard to clip and unclip draws. Most other harnesses have the gear loops attached to the bottom of the waistband, allowing for more clearance. This is a fairly minor detail but can get annoying, especially when cleaning routes.

mammut alnasca climbing harness women review - the tiny belay loop on the alnasca.
The tiny belay loop on the Alnasca.
Credit: Eric Bissell

The Alnasca also has a small haul loop but it is hard to fiddle a carabiner into, so we rarely bothered with it during testing. The belay loop is another area where Mammut slimmed down when making this harness. It's one of the skinniest belay loops we've ever used, which could be a durability concern in the long term — just keep an eye on it as the harness ages! Much like Mammut's other lightweight models, this belay loop is half the width of a standard belay loop, which definitely raises concerns about longevity.


Because it is designed for such a specific use and designed with saving weight in mind, the Alnasca is not the most versatile harness we've tested. If you are mainly climbing sport routes and climbing in the gym, it is a no brainer, but we really wouldn't recommend multi-pitching in this harness due to its simple, featherweight design. The haul loop is not really functional, and the gear loops feel a bit tight once you start loading them up with gear.

mammut alnasca climbing harness women review - the gear loops on the alnasca are very small and narrow - it would...
The gear loops on the Alnasca are very small and narrow - it would be challenging to put a rack of cams on this harness without it feeling overcrowded.
Credit: Eric Bissell


The leg loops on the Alnasca, while not being fully adjustable, are stretchy enough to provide plenty of movement and clearance over climbing pants. The waist belt covers a wide range of sizes and is easy to adjust. It takes some work to remove the leg loops though, so we rarely took off our leg loops when walking around in this harness. Luckily, we didn't need to, since it was so comfortable to wear around.

mammut alnasca climbing harness women review - the alnasca doesn't have adjustable leg loops and is not very...
The Alnasca doesn't have adjustable leg loops and is not very versatile in general.
Credit: Eric Bissell


This harness costs a pretty penny, especially for one that isn't very versatile. When you buy the Alnasca you are paying for Swiss engineering applied to a lightweight climbing harness. This one will fit well, feel incredibly light, and breathe on warm days. If you are seriously concerned about shedding weight on your sport proj, or just want a light harness to have in your gym bag, the Alnasca could be worth it.

mammut alnasca climbing harness women review - though it looks flimsy, the alnasca has a plastic reinforced tie-in...
Though it looks flimsy, the Alnasca has a plastic reinforced tie-in point, adding a bit of durabilty to this ultra-light harness.
Credit: Eric Bissell


For sport climbing and gym climbing where you don't need a ton of storage space on your gear loops or a ton of padding on your leg loops, the Alnasca is hard to beat. This is a well-designed lightweight model made for gym climbing. Its wide mesh waistband distributes weight well, without inhibiting movement. The leg loops are sleek enough to wear this harness around for hours without hardly noticing it's there. The belay loop is definitely sleek — almost to the point of worrying about its durability. The gear loops are also so small that it's hard to fit a lot of gear on them. These downsides are not a huge deal if you plan to mostly use this harness in the gym, though. For that reason, the Alnasca is our Top Pick for Gym Climbing.

Jane Jackson
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