Altra StashJack Review


Basic description:  A lightweight hooded external shell designed to be worn with a hydration pack, with the capability to be put on and taken off without removing the hydration pack. The entire jacket also compresses down into a very small pocket that is stashed on your front waist area for easy access when conditions require an extra layer.

MSRP: $130

Quick summary: The Altra StashJack is a unique piece that is ideally functional for specific conditions: namely, running with a hydration pack in variable conditions that require you to apply and remove a weather resistant layer multiple times. The innovative design allows quick application and removal, while lightweight design and high compressibility are excellent for “just in case” stowability.


  • Unisex style
  • Fabric: 100% Nylon ripstop
  • Weight 3.3 oz
  • Trimmed and flat lock seams
  • Wind and water resistant
  • Loose fit
  • Stowable hood
  • Back length: 26.5” (based on size Medium)
  • Reflective logo
  • Velcro attachment on rear waist
  • Two color options

Deep dive:

Convenient Front Storage

Convenient Front Storage

The premise of the Altra StashJack is to solve the inherent difficulty of combining a jacket and hydration pack on a long run. Altra’s co-founder, ultrarunner Brian Beckstead invented the StashJack so he could put on or take off a jacket in seconds without taking off his pack and with minimal need to slow his running speed.

Stashjack Pouch

Stashjack Pouch

For that purpose, the StashJack is rather brilliant. You wear your backpack like normal, and fasten the StashJack around your waist with an elastic band and clip fastener. When the first chill comes on, unfurl the StashJack from its waist pouch, pull it over your head like an apron, and connect the tails with the Velcro fasteners below your pack and above your waist.  When the weather gets warm, simply reverse the process and stash the jacket back into the front pouch without breaking stride.

Stashjack Rear

Stashjack Rear

The StashJack is extremely simple to use, and saves significant time in preventing the need to get in and out of your hydration pack each time you want to add or remove your external layer. The jacket is superlight and highly compressible, and the elastic waistband prevents any bouncing of the jacket when it’s stowed in the front pouch.  When the jacket is being worn, the deep front zipper allows you to access front-side pockets or water bottles.  It’s an ingenious option for hikers, mountain bikers, or anyone who wears a backback in variable weather conditions.

Easy Access to Front Pockets

Easy Access to Front Pockets

A few limitations to note: From a weather resistance standpoint, the StashJack is on the light end of the spectrum, so this is definitely more of a spring/fall jacket than a true cold-weather piece. Although the hood is easily opened or stowed, it is not adjustable or fastenable around your face; an elastic trim band holds it in place fairly well during mild to moderate breezes, but high winds can twist it or blow it off. And aside from the pouch itself (which rides on the inside when the jacket is worn), there aren’t any pockets on the front to stow small items or briefly warm your fingers.

Obviously the biggest consideration to using the StashJack is whether you use a hydration pack often enough to justify it. If you do the majority of training and racing with a waist pack or handhelds, the StashJack serves little purpose beyond providing extreme ventilation on your backside – which actually isn’t such a bad idea either.


Altra’s StashJack is a highly innovative, ingeniously simple product to regulate your temperature and provide weather resistance in variable conditions without losing time along the way. However, if you don’t use hydration packs frequently and don’t want a jacket with a big hole in the back, look elsewhere for your lightweight shell.


About Author

Donald is a physical therapist, California native, barefoot aficionado, and father of three with more than 25 years of experience in endurance sports. He was a collegiate rower at UCLA, then dabbled in marathons and Ironman-distance triathlons before falling in love with ultras in the early 2000s. His favorite locations to run include Marin County, CA, and the Sierra Nevada mountains, and he loves exploring America's National Parks. When he's not training for ultramarathons, he enjoys hiking or slacklining with his family in Monterey County, CA.

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