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Outdoor Research Enigma Bottoms Review

If you like to move fast and light, these impressively breathable bottoms can keep up
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Outdoor Research Enigma Bottoms Review
Credit: Backcountry
Price:  $69 List
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Manufacturer:   Outdoor Research
By Aaron Rice ⋅ Senior Review Editor  ⋅  Nov 19, 2019

Our Verdict

Superman's leggings? They might as well be, as the Outdoor Research Enigma Bottoms easily take our Top Pick for Lightweight/Aerobic Activity. These are one of the lightest pairs of long underwear in our review, but prove themselves worthy with a distinguishable level of warmth backed up by unmatched breathability. Designed for running up mountains — not standing on top of them — these fun-loving leggings are purposefully designed for ambitious ski tours, fall mountain running, and fast-and-light alpine climbing when you need to fight off just a bit of a chill on the approach. Built with OR's proprietary driRelease blend of Merino wool and polyester, these fast-wicking bottoms will dry off on your body as quickly as you can produce sweat.
Fast wicking and quick drying
Thin material is not warm
Articulated seams could create constrictions

Our Analysis and Test Results

The Enigma bottoms were a bit of a mystery when they first arrived on our doorstep. But throughout our testing process, they proved themselves time-and-again as masters of aerobic adventure. Whether it was running, climbing, or backpacking through steep terrain, this pair of slim-fitting long underwear worked efficiently to keep us continuously dry. A skillfully designed merino/poly blend pairs with the tight, athletic cut of these bottoms to wick-up and quickly evaporate sweat, while at the same time achieving a comfortable next-to-skin softness.

Certainly not our first choice for endeavors into the cold — not unless you're going to be working up some serious body heat — we loved these bottoms for cold morning trail runs, and cannot wait to take them out for long, spring ski tours. The thin material is definitely susceptible to snags and tears, but these bottoms proved surprisingly abrasion-resistant during our lab testing. While an overly articulated seam design could present issues for some muscular builds, for the skinny-legged, fast-and-light alpinist, these bottoms could be the future of long underwear.

Performance Comparison

outdoor research enigma bottoms - fast and fun, these bottoms are perfect for cool fall weather, and...
Fast and fun, these bottoms are perfect for cool fall weather, and any activity in the winter that works up a sweat.
Credit: Aaron Rice


Considering that these are easily defined as a lightweight pair of long underwear, we were impressed by the warmth afforded by the Enigma bottoms. They perform very much like other, similarly weighted base layers — those in the ballpark of 150 g/m² — in that they are not meant for standing around in Arctic conditions, but rather are designed to thermoregulate when we work up a sweat efficiently.

The main difference between these bottoms and other, similarly weighted options, is that these achieve the same level of warmth without the same level of bulk. The secret to a warm base layer, a warm puffy, or a warm sleeping bag is that material loft creates a space to trap air, which is then warmed by our body heat. So it is impressive to have a layer that can be both skin-tight, and effectively trap enough warmth to keep your muscles in motion.

outdoor research enigma bottoms - did someone say alpine start? these bottoms were enough for the...
Did someone say alpine start? These bottoms were enough for the warm-sleeper, but required us to get up and moving to stay warm.
Credit: Jill Rice


These bottoms rock and the proprietary driRelease is the reason. This lightweight fabric is meant for athletics — slim fitting, moisture wicking, and quick drying. The 12% Merino wool is the piece you can thank for bringing to the table the superior moisture-wicking capability we all seek in a baselayer. The rest of the driRelease fabric is made up of fully-recycled polyester, which takes over after that sweat is wicked up and works its magic to evaporate any and all moisture quickly.

The Enigma bottoms dry off on your body at a rate that will make you believe that you aren't even sweating. We couldn't believe how well these performed, even when the temperatures really heated up during testing. Perfectly designed for any highly-aerobic activity, we loved long trail runs in these bottoms, and cannot wait to get them out in the spring for long, sunny spring tours — where lightweight breathability truly shines.

outdoor research enigma bottoms - you too can feel as fast as a superhero when running in these...
You too can feel as fast as a superhero when running in these awesome leggings!
Credit: Jill Rice

Comfort and Fit

We believe it's worth mentioning, right off the bat, that these are not 3/4-length bottoms, nor are they available in a boot-cut option — we're pretty confused as to why they are being marketed as such through some sellers, but we don't want you to be fooled!

outdoor research enigma bottoms - fit of the or enigma bottoms: slim-fitting and athletically cut all...
Fit of the OR Enigma Bottoms: slim-fitting and athletically cut all the way through. Our tester is 5'10", 160lbs wearing a size medium.
Credit: Jill Rice

The Enigma bottoms might as well define next-to-skin comfort. These are hip-hugging, butt-hugging, knee-hugging… you get the idea. They are cut like yoga leggings, designed to offer athletic mobility regardless of what type of pants you are wearing them underneath. Considering the fit and colorway, when we wore them as running tights, we sort of felt like Spiderman — and that felt kind of awesome.

Outdoor Research has a history of working to improve access and preservation of our outdoor playgrounds, and by incorporating what they call Environmentally Correct Origins (E.C.O.) fabrics — like sustainably produced Merino wool, blended with 100%-recycled polyester — the Enigma bottoms further that cause. On top of all that goodness, this blended fabric is super smooth when worn next-to-skin.

outdoor research enigma bottoms - soft and breathable?! the merino and recycled poly blend makes these...
Soft and breathable?! The merino and recycled poly blend makes these a great option for wearing next-to-skin, with no uncomfortable heat pools or sweat spots.
Credit: Jill Rice

These bottoms employ flatlock seams to help promote the stretch of the poly-infused driRelease knit, and these seams run all over this base layer. We would say that the Enigma bottoms are approaching over-designed in this regard. While the articulation — including a gusseted crotch and isolated knee panels — allows for ninja-like flexibility, there are some pitfalls. It is really cool that designers could eliminate the outside seam of the pant by inserting these knee panels. However, the top seam of the panel runs directly across the muscular part of the thigh above the knee. This didn't present a problem for the skinny-mountaineer legs of our head tester, but we could foresee this being a point of constriction for other athletes (cyclists, for instance.)

outdoor research enigma bottoms - future-tech. these bottoms had more articulation than any other pair...
Future-tech. These bottoms had more articulation than any other pair in our review: a functional fly, gusseted crotch, and isolated knee panels makes for a lot of seams.
Credit: Jill Rice


The Enigma bottoms certainly mystified us when it came to expectations of durability. We expected the ultra-thin material to be susceptible to punctures and easy tears — but even on off-trail runs through the snag-heavy sagebrush and cactus-covered desert plateaus of the southwest, this layer walked away practically unscathed. The only spot where we noticed wear is that a few of the seam ends became exposed around the cuffs.

We gave these bottoms the benefit of the doubt after our abrasion test. Although they showed signs of surface scuffing, in no way did they show any signs of forming a hole. In fact, a few days after the test, we even had a tough time finding the exact spot that we had rubbed so aggressively. Besides the typical stretch — particularly around the ankles — that comes with the inclusion of wool in any blended knit, the compression factor of these bottoms was re-invigorated after a wash and line-dry.

outdoor research enigma bottoms - after extensive field-testing and a few washes, we noticed a few of...
After extensive field-testing and a few washes, we noticed a few of the flatlock seams separating along the cuffs -- pretty minor considering the heavy use (or is it abuse?)
Credit: Jill Rice


Is the Enigma the future of lightweight long underwear? It just may be, offering a unique Merino/poly-blend that offers impressive warmth, breathability, and surprising durability considering its ultralight weight. Not quite as expensive as 100% Merino layers, but not quite as wallet-friendly as full-synthetic options, these bottoms seem to hit a Goldilocks zone in terms of performance for the price — particularly for those engaged in highly aerobic activities.

outdoor research enigma bottoms - we couldn't help but feeling like a superhero every time we pulled...
We couldn't help but feeling like a superhero every time we pulled these on. You can see it on our face -- stoke for the day's adventure!
Credit: Jill Rice


Great for Halloween costumes, great for long runs up mountains, the Outdoor Research Enigma bottoms are a versatile tool designed for practically everything but the coldest of days. It doesn't take a Colonel Mustard to figure out how these lightweight bottoms snagged our Top Pick for aerobic activity, and we're excited to see how the technology that goes into these bottoms continues to develop. Go confidently knowing that the sustainable goodness is equally matched by the performance of this super-pair of long underwear.

Aaron Rice