REASONS TO BUY
Flexible waistband
Very warm
Stretchy
Soft on the inside
REASONS TO AVOID
Too warm for hot summers
Not fully waterproof
REI Co-op Activator - Women's Review
These pants are great for keeping cozy in cold, windy conditions
Credit: Elizabeth White
By Elizabeth White ⋅ Senior Review Editor ⋅ November 15, 2025
Our Verdict
The REI Co-op Activator Pants are rugged, wind-resistant, warm hiking pants that feel more like sweatpants—making them perfect for comfort in cold conditions. We love the stretchy waistband and elastic blend of nylon, polyester, and spandex. While the outer layer of these pants is tough enough to prevent wind from puncturing through and provide non-PFAS water repellency, the inside is soft and velvety, like a cozy pair of thermals. While we cherish these pants' comfort and love them both in and outdoors, we couldn't imagine wearing them in hot, muggy climates, as they're more of an insulating pant. But, these pants are perfect for spring and fall hiking, and even kept us comfortable while trekking through the snow.
Our Analysis and Test Results
These pants gave us the flexibility we needed to cross streams and climb over rocks with ease.
We felt safe crossing streams knowing our phone was safely zipped away in the deep hand pockets.
Credit: Elizabeth White
Comfort and Mobility
If you're looking for a pair of hiking pants that feel like the perfect blend of yoga pants and sweatpants, these are the ones. High-stepping is no problem—we could lift our foot over our head and it wouldn't be any burden on the seams (if we were that flexible). They also kept us incredibly warm in the late fall while trekking in the windy Sierra Nevadas.
We appreciate the flexible waistband in the back of the pants, which is great for those whose weight fluctuates a lot, or who frequently experience bloating.
These pants are super stretchy, allowing us to move freely.
Credit: Elizabeth White
Venting and Breathability
These pants are built specifically for blocking the wind, so they aren't the most breathable, and they don't come with a ton of venting features. But, they have a low-profile, built-in cinch cord that allows us to adjust the hem to our preferences. So, if you want to let in more airflow, you can. But, it's not much.
Weather Resistance
We wore these pants in whipping winds and pouring rainfall. We also hiked around in these in the late fall when temperatures had dropped below 40°F. In high winds and cold temps, these pants kept us cozy and fairly warm. We almost felt like we were wearing a light pair of thermals underneath. While these pants do an okay job of repelling water, they wouldn't be our first choice for a rainy day.
The main draw of these pants is their impressive insulation. We wore these pants in 40 mph winds, and they held up shockingly well.
When walking in sprinkling rain, we were able to walk for about 40 minutes before we noticed any sort of seepage. But when we were in the pouring rain, it took about 20 seconds to feel some wetness against our skin.
The REI Co-op Activator Pants after 2 minutes of being drenched in water. These pants are quite water repellant, but not fully water-proof.
Credit: Elizabeth White
Construction Quality
We bushwhacked through manzanita fields and scooted our butts down granite rocks in the Activator pants, and they made it out without a scratch thanks to their durable outer shell. These pants are made up of 11% spandex, 63% nylon, and 26% polyester. The high percentage of nylon makes these pants unsusceptible to tears, and the design makes it so that there aren't many protruding components to snag on a bush or branch—apart from the belt hoops, but we haven't had any troubles with it thus far.
These pants easily weathered bushwhacking and brushing up against granite.
Credit: Elizabeth White
Versatility and Features
The Activator pants can be worn from the trail to the brewery. Because they come in plain, neutral colors, we would feel comfortable wearing them while running errands and even in a more casual workplace. These are so comfortable that we even found ourselves lounging around the house in them. However, we don't love how visible the REI symbol is; otherwise, these pants are great in most situations.
We'd happily bring these pants both hiking and climbing, as they have pretty good stretch. Though, we wouldn't bring them to the gym, since the material is thick and we'd probably get too warm. We'd also be happy in these pants whether we were hiking Mount Whitney or walking the dog, as the material is thick and sturdy enough to withstand even technical terrain, and comfortable enough for a stroll around nearby trails.
We were happy to take these pants anywhere we went, whether it was backpacking, hiking with the pup, or grabbing beers with friends.
Credit: Elizabeth White
As mentioned, while these don't come with a belt, we love that they have a built-in waistband—and they have belt loops that feel pretty sturdy. It also comes with two snap buttons, and while we usually aren't fans of snaps, they never came undone, even when high-stepping and making technical maneuvers in the mountains.
We were able to fit our phone and laughably large keys in the front hand and back pockets, while we fit smaller items in the lower leg pocket. With pants like these, who needs a bag?
There are five pockets in total, with three zippered pockets in the front (two large enough to fit an iPhone 13 and some other small accessories, and one zippered pocket that's bit enough to fit small items like AirPods or doggy bags. Finally, there are two less-secure back pockets with snap buttons.
The cinches at the hem stay put. We love that they can be tucked away inside the pants for a low-profile look. We also never felt the cinch chafe against our ankles.
Should You Buy the Womens REI Co-op Activator Pants?
If you plan to hike in a cold, windy place, these are the pants we recommend the most. The soft-shell material on the outside is perfect for blocking wind, while the inside is soft and insulating enough to keep us happy and warm. But, we don't recommend these pants if you're planning to hike around in hot, humid places.
What Other Hiking Pants Should You Consider?
Some places experience significant temperature swings throughout the day, especially in midsummer. You could be sweating and chugging water at noon, and shivering by 8 PM. For these conditions, zip-off pants (pants that convert to full-length pants to shorts) can be a great solution. The REI Co-op Sahara Convertible are a comfortable, versatile pair of hiking pants that will keep you comfortable throughout the day.
If you're adverse to the idea of zip-offs but still want a versatile, breathable pant, the Outdoor Research Ferrosi Pant allows your legs to breathe while also blocking out wind and rain with its durable water repellent material.Side-by-Side Comparison
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—Elizabeth White
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