It’s spring in Alaska, and I’m on a multihour run in the temperate rainforest. Moss clings to the branches of old-growth forests, and waterfalls cascade from the precipitous mountainsides above. The rain is ceaseless. Combined with an ambient air temperature of around 35 degrees, these are the type of conditions where I can’t stop moving without risking hypothermia in a remote setting.
Pausing briefly for a snack break, I pull out my three extra layers and don them under a large Sitka Spruce. Carried in the Hyperlite Pemi 15, my extra layers are safe and dry, allowing me to comfortably enjoy another outing in some of the harshest conditions possible for a backcountry run.
For years, the name Hyperlite Mountain Gear has been synonymous with durability, high performance, and excellent craftsmanship. With its first foray into the running vest market, it continues that legacy. After over 100 miles of testing, I can confidently say that the Pemi 15 is a worthwhile addition to any mountain athlete’s arsenal.
In short: The Hyperlite Pemi 15 is a purpose-built running vest for fastpacking, mountain running, and long days on backcountry trails. Its 15L capacity offers enough room for extra layers, food, and technical gear while maintaining a stable, bounce-free fit thanks to its full connection harness and welded foam back panel. The ALUULA 97 fabric and thermo-welded construction deliver exceptional durability and water resistance without unnecessary weight.
Multiple front storage pockets, trekking pole and ice axe carry options, and a roll-top closure make it well-suited for everything from trail ultramarathons to high alpine objectives. It does have flaws, including chest pocket configuration and breathability. But at 12.4 ounces, the Pemi 15 strikes an impressive balance between lightweight performance and heavy-duty carrying capability.
Materials
ALUULA 97, Thermo-welded construction
Best for
Rugged trail runs, big mountain scrambles, fastpacking
Pros
- Extremely light
- Durable materials
- Bounce-free carrying system
- Supportive and protective back panel
- Multiple pole carry configurations
Cons
- Sweaty back panel
- Small chest pockets
Hyperlite Mountain Gear Pemi 15 Review
Design and Construction
Named for New Hampshire’s legendary Pemi Loop (short for Pemigewasset Loop), the Pemi 15 is one of the burliest running packs I’ve tested. It’s ideal for runners and fastpackers who need the carrying capacity of a lightweight backpack and the stability and comfort of a running vest.
With 15 L of storage, it has enough space for extra clothing, food, hydration, and gear. It’s well-suited for ultramarathons, long alpine traverses, and self-supported mountain adventures. Despite its generous capacity, the Pemi 15 maintains a close, body-hugging fit that minimizes bounce and keeps the load secure over rough terrain.

The Pemi 15 is constructed from ALUULA 97, an ultralight composite material that delivers an exceptional strength-to-weight ratio while resisting abrasion and shedding moisture. Thermo-welded seams eliminate unnecessary stitching, reducing weight and improving weather resistance. A molded foam back panel adds structure, enhances comfort, and helps protect the back from any hard objects inside.
The vest-style harness has two elastic sternum straps that fine-tune the fit and keep the vest secure. Each shoulder strap has a water bottle sleeve, a zippered pocket, and two stretch mesh stuff pockets. This array of pockets is great for keeping soft flasks, snacks, or a phone within easy reach.
A roll-top closure compresses the load and lets you adjust the pack’s volume depending on your objective. A hook strap over the top adds compression if needed, or can be easily removed.
The Pemi 15 includes dedicated attachment points for trekking poles and ice tools, allowing you to securely stow equipment when your hands are needed. An external stuff pocket offers quick gear stowing. A vertical side zip — an unusual offering in running packs — offers easy access into the main compartment.
In the Field

I tested the Hyperlite Pemi 15 on the trails and peaks of the Chugach Range surrounding my home in Anchorage, Alaska. On my first adventure with this vest, I wore it for a multihour trail run in 35-degree weather and heavy rain to test its carrying capacity and water resistance. Over the course of 2 months, I put in over 100 miles with this pack, ranging from off-trail alpine scrambles to long trail runs.
During my testing, I experimented, from trying different trekking pole carrying configurations to intentionally overloading the pack to test its comfort under load. My process is based on real-world testing. I also tinkered with the pack in a more lab-like setting to isolate specific aspects of the pack I was seeking to examine.
What I Loved

As an admittedly longtime admirer of Hyperlite Mountain Gear products, I love the roll-top system found in most of its bags. This is an excellent way to increase or decrease the volume quickly as needed.
The vertical side zip is also an excellent feature. While I was at first skeptical about how much I would use it, it quickly became my go-to method to access the main compartment, and I now rarely unroll the top.
While Hyperlite is renowned for using Dyneema materials in higher-volume packs, the new ALUULA fabric has proven to be excellent. Running in heavy rain, it kept my extra layers dry. It also boasts an impressive weight-to-strength ratio. So far, it has held up to bushwhacking and scraping against rocks with no signs of slowing down.

For a running vest, the Pemi 15’s comfort while under load is more like that of a dedicated backpacking pack. I easily carried loads that would crumple other vests. It’s perfect for carrying heavier items like rock climbing gear or extra food and water for longer efforts.
For me, no technical adventure is complete without trekking poles or an ice axe. The Pemi 15 has a couple of different ways to carry these essential tools. The side compression straps can carry the poles vertically, or the dedicated bungees carry them horizontally across the bottom of the pack. Either way is a secure, streamlined attachment.
Room for Improvement

The Pemi has a couple of small things that I would like to see improved. The first being its chest pocket system.
The dedicated bottle pockets are noticeably small. I struggled to fit a bottle over 450mL in this pocket without the top flopping out. While it does come with elastic loops to help keep the tops of the bottles in place, larger bottles still flopped around awkwardly. While Hyperlite does make dedicated bottles that may fit better, the three different bottle types I tried all struggled to fit in these pockets.

I also had a hard time fitting my usual amount of items in the chest pocket system. At minimum, I carry one soft flask, my cellphone, and about 800 calories in the form of bars, gels, and snacks.
While the zippered pockets are great for keeping items secure, they are too small for a phone when a water bottle is also carried. Additionally, the stretch pockets are slightly small.
The other area that I would like to see improved upon is the back panel. While it is the most supportive back panel of any running vest I’ve used, it lacks breathability. I frequently found my back soaked with sweat after a run with the Pemi 15, as the sturdy back panel does not allow much airflow. While the back panel is great for protection from hard items inside, like climbing gear, the trade-off is a lack of breathability.
Conclusion

The Hyperlite Mountain Gear Pemi 15 is a premium-priced running vest built with premium materials, and its price reflects that. Its 15L capacity provides enough space for everything from ultramarathons to fastpacking trips and alpine objectives, while its vest harness delivers a secure, bounce-free carry even when fully loaded.
Thoughtful features like a roll-top closure, accessible front storage, side zip access, and trekking pole and ice tool attachments make it an exceptionally versatile option for moving quickly through technical terrain. While its premium price may be difficult to justify for casual runners or those just getting into trail running, those willing to spend the extra money will appreciate its lightweight construction, outstanding durability, and carefully refined design.
With a little room for improvement, Hyperlite’s first foray into the running vest market is off to a solid start. For those willing to invest, the Pemi 15 is an excellent choice built to handle years of demanding use.
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