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Arc'teryx Rho Bottom - Women's Review

This lightweight synthetic long underwear bottom can do it all, thick enough to perform on its own or within your cold weather kit
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Arc'teryx Rho Bottom - Women's Review (This photo displays the merrow stitch seams above the pocket that became fuzzy from the friction from interacting with...)
This photo displays the merrow stitch seams above the pocket that became fuzzy from the friction from interacting with our ski bibs.
Credit: Trish Matheny
Price:  $100 List
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Manufacturer:   Arc'teryx
By Trish Matheny ⋅ Review Editor  ⋅  Apr 12, 2024
78
OVERALL
SCORE


RANKED
#6 of 22
  • Warmth - 25% 7.5
  • Breathability - 20% 8.0
  • Comfort and Fit - 20% 9.0
  • Durability - 15% 6.5
  • Drying Speed - 10% 8.0
  • Layering Ability - 10% 7.5

Our Verdict

The Arc'teryx Rho Bottom is our favorite layer for multi-sport performance thanks to the exceptional fit, complete with a high-rise waistband and minimalist design features such as a gusseted crotch and articulated patterning for increased mobility. The Torrent stretch fleece and brushed interior amp up the comfort of these leggings, enhancing wicking capabilities and overall breathability. The stretchy fit is functional on its own, whether out for a run or during yoga, and it's easily layered with your ski bibs to increase cold-weather performance without losing a ton of breathability. We're confident these lightweight bottoms will quickly become a go-to layer for your cool-to-cold weather activities. For a look at some of the top competitors when it comes to layering, check out our best women's long underwear review, where we investigate a wide range of options.
REASONS TO BUY
Lightweight
Versatile
Ample warmth
Great fit and waistband
Soft synthetic fabric
Thigh pocket
REASONS TO AVOID
Pricey
Merrow seams accumulate fuzz from friction
Editors Note: We updated this review on April 12, 2024, to include new purchase recommendations for other high-performing long underwear bottoms.

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Bottom Line The slim-fitting design is not only flattering but also enhances thermoregulation and overall moisture-wicking capabilitiesWhile not recommended as a stand-alone piece due to the see-through polyester fabric, we love the superior breathability that helps keep us warm and dryThese bottoms offer a ton of warmth and substantial comfort at a more affordable priceThese lightweight tights feature a soft and stretchy fabric that is easy to layer and maintains substantial warmth when dryWhile these bottoms lack warmth for the coldest months of the year, they are a great option for those seeking a three-season stand-alone legging
Rating Categories Arc'teryx Rho Botto... Patagonia Capilene... Minus33 Franconia M... REI Co-op Midweight... Baleaf Fleeced Line...
Warmth (25%)
7.5
8.5
9.0
7.0
4.0
Breathability (20%)
8.0
9.0
7.0
6.0
7.0
Comfort and Fit (20%)
9.0
8.0
9.0
8.0
8.0
Durability (15%)
6.5
6.5
8.0
7.0
7.0
Drying Speed (10%)
8.0
8.5
7.0
8.0
7.5
Layering Ability (10%)
7.5
7.0
6.0
7.0
8.0
Specs Arc'teryx Rho Botto... Patagonia Capilene... Minus33 Franconia M... REI Co-op Midweight... Baleaf Fleeced Line...
Measured Weight (Size Small) 4.80 oz 4.90 oz 7.52 oz 6.40 oz 8.80 oz
Material 84% polyester, 16% elastane 92% recycled polyester, 8% spandex 100% Merino wool 92% recycled polyester, 8% spandex 87% polyester, 13% spandex
Insulation Weight Class Lightweight Midweight Midwewight Midweight Midwewight
Smelly Over Time? Yes Yes No Yes Yes
Odor Control Fabric Torrent HeiQ Fresh Naturally odor resistant No No
Cuts Avaliable Full-length Full-length, boot-length Full-length Full-length Full-length
Listed Fabric Weight (g/m²) 190 g/m² 129 g/m² 235 g/m² Not disclosed Not disclosed

Our Analysis and Test Results

Thanks to their high-performing and minimalist design, the Arc'teryx Rho is one of our favorite pairs of long underwear bottoms. The next-to-skin fit is flattering and functional when considering the warmth these lightweight bottoms offer, whether worn alone or within a layered system. We love the high-rise waistband and stash pocket on the thigh, especially when out for a long run or Nordic ski. We're confident these leggings will impress you with their versatility, whether doing yoga or skinning uphill in the backcountry.

Performance Comparison


Our favorite pair of long underwear for multi-sport performance are the Rho Bottoms, thanks to a stretchy and comfortable design that features a handy stash pocket and can be worn on its own or within a cold weather layered system.
Credit: Trish Matheny

Warmth


While the Rho is not designed to provide warmth for the coldest months of the year, our testers love the ample warmth it has when worn as a stand-alone piece during spring and fall training runs, in addition to the effective warmth when layered below additional ski bibs and puffy pants during winter. Arc'teryx recommends these bottoms for cool to cold weather, and we would agree.


During our extensive testing period, we recorded the temperature ranges where these bottoms provided enough warmth to remain comfortable. We found the sweet spot to be somewhere between 30-50 degrees Fahrenheit, depending upon the conditions. They were even comfortable down to the teens while backcountry skiing with ski bibs layered over the top. Anything above 60 degrees in these bottoms, and you'll wanna dial back the intensity. Overall, we were impressed with the lightweight and slim-fitting synthetic design that enhances the thermal efficiency of these long underwear bottoms.

Our testers love this layer for added warmth during spring training runs when you're surrounded by snow but they've plowed your favorite road.
Credit: Trish Matheny

Breathability


The 84% polyester and 16% elastane material, combined with the Torrent stretch fleece and Polygiene treatment, help to manage moisture generated during activity. The fabric truly wicks moisture away from the body and allows the vapors to escape when exposed to fresh air. We love that the fabric is thick enough to be worn on its own yet remains lightweight and porous enough for airflow to penetrate the synthetic fibers.


During our testing period, we noticed that though the waistband is very minimal and low profile, this is often the spot where sweat would pool. This is likely because that's the area often covered up with another layer or a heavy backpack, thereby preventing any fresh air from aiding in breathability. Overall, we gave the Rho high marks for its effective moisture management capabilities.

arc'teryx rho bottom for women - this lightweight bottom doesn't breathe as well as other more air...
This lightweight bottom doesn't breathe as well as other more air permeable options in our lineup, however, we appreciate that they can be worn in a greater range of temperatures.
Credit: Trish Matheny

Comfort and Fit


The Rho has one of the most functional fits we've tested, perfect for a wide variety of activities. The design is minimal and next-to-skin, yet includes very thoughtful details such as an elastane fabric that is brushed for softness and allows for stretchy comfort. The first time we tried on these bottoms, they almost felt compressive, though, over time, they stretched enough to increase comfort without losing any support.


The fit in the Rho is true to size, yet slim, so it's perhaps best to size up if you find yourself in between sizes. We love the thick and high-rise waistband that is both flattering and functional, as these bottoms never required adjusting, whether we were backcountry skiing, trail running, or doing yoga. The design also features a gusseted crotch and articulated patterning, which we found to aid in a full range of motion and increased mobility. We highly recommend the Rho if you're after a versatile bottom with exceptional comfort and stretch performance — it even has a stash pocket for energy gels, bars, or a smartphone.

We love the high waisted design and slim fit offered by this...
We love the high waisted design and slim fit offered by this lightweight bottom.
Moisture wicking capabilities made the Rho one of our go-to's for...
Moisture wicking capabilities made the Rho one of our go-to's for shoulder season training and this stash pocket really came in handy for energy gels, bars, or a smartphone.

Durability


While we haven't experienced any major durability with the Rho bottoms, we don't recommend them for activities like rock climbing or trail running through technical rocky terrain. The polyester fabric is incredibly durable, especially considering its lightweight construction, but we could imagine it being prone to rips or snags when encountering sharp rock. This is not a bottom we'd recommend for off-trail, either. We consider these bottoms more of a versatile base layer rather than tights or yoga pants, but we're psyched that they perform both inside and outside of our ski bibs. The merrow stitch and flatlock seams effectively hold the layer in place, but we did notice a bit of fuzz on top of the seams after layering beneath our bibs.


Though Arc'teryx really boasts about its odor-resistant Torrent fabric with Polygiene treatment for long-lasting odor control, we experienced quite the opposite. After a couple months of testing, we found that these bottoms really hang onto odor post activity. This is true of most polyester synthetic bottoms though, and we found that it wasn't noticeable enough for partners to complain. If odor-free construction is what you're after, we'd recommend a Merino wool option for better performance.

arc'teryx rho bottom for women - we can appreciate the durable seams on the rho, strategically placed...
We can appreciate the durable seams on the Rho, strategically placed in high traffic areas prone to friction.
Credit: Trish Matheny

Drying Speed


When considering drying speed for base layers, we wanted to simulate what it's like to wash and dry the layers while on an extended backcountry trip. We soaked, wrung out, and hung the Rho on a line to dry before recording the speed. These leggings dried in a speedy 43 minutes on the line.


We really enjoyed the Rho while on training runs in the spring, so after an hour of intense movement, we started our timer to record their drying speed on the body. While results varied, it often took around 40 minutes to dry completely, usually taking the longest time around the waistband. We attribute this performance to a quick drying and moisture-wicking polyester/elastane combination.

arc'teryx rho bottom for women - these lightweight synthetic bottoms only needed 43 minutes to dry on...
These lightweight synthetic bottoms only needed 43 minutes to dry on our climbing rope and only 40 minutes on body post activity.
Credit: Trish Matheny

Layering Ability


The Rho is surprisingly easy to layer thanks to its minimalist design. The next-to-skin fit makes for easy layering over the top, and the high-rise fit allows for additional layers to fasten at the natural waistline with minimal bulk.


While we love the addition of the stash pocket on the thigh, we found that it was best not to use this pocket with our ski bibs layered over the top because it was in the same location as our beacon pocket. As you might imagine, using both pockets in the same location was pretty bulky and distracting while skinning uphill.

arc'teryx rho bottom for women - these lightweight bottoms were easily layers beneath our ski bibs...
These lightweight bottoms were easily layers beneath our ski bibs, we just noticed it was easier without anything in the stash pocket because it was in the same location as our beacon.
Credit: Trish Matheny

Should You Buy the Arc'teryx Rho Bottoms?


If you're after a lightweight synthetic pair of long underwear bottoms that can really do it all, the Rho is a great choice. The minimalist design features thoughtful patterning and a flattering and functional fit that increases comfort and thermoregulation. Though a little more of an investment, we're confident you'll be impressed with these bottoms, whether worn on their own or within a layered system.

arc'teryx rho bottom for women - multi-sport long underwear performance at its finest, whether...
Multi-sport long underwear performance at its finest, whether logging road miles during the shoulder seasons or worn at the base of your cold weather kit, these bottoms don't disappoint.
Credit: Trish Matheny

What Other Long Underwear Should You Consider?


If you are interested in a synthetic long underwear bottom with a more stripped-down design, check out the Patagonia Capilene Midweight Bottom. The Midweight offers a ton of durability and is our lead tester's favorite overall workhorse when it comes to year-round use. If breathability is more important than versatility, but you don't want to sacrifice synthetic comfort and fit, check out the Patagonia Capilene Thermal Weight. If you want to throw down for the very best Merino wool option that we've tested, consider investing in the Icebreaker 200 ZoneKnit Merino Leggings. These high-waisted bottoms offer high performance in breathability and year-round warmth without retaining any odor from your efforts. And if you're curious about what a Merino wool and synthetic blend is all about, check out the Smartwool Intraknit Thermal Merino Bottom. These bottoms are a better choice for super cold weather and can be worn on their own or below your ski bibs.

Trish Matheny