Welcome! Ultralight backpacking is my passion, and keeping up on new technologies, gear, and techniques relevant to UL backpacking is what floats my boat. I'm always looking for the lightest, most functional gear to improve a lightweight or ultralight backpacking kit, and report my impressions and field testing results here. For hikers wanting to keep up on the latest and greatest ultralight backpacking gear, this is a good place to hang out. Also, there is a lot of information here (and on our informational website Southwest Ultralight Backpacking) on useful techniques and backcountry etiquette -- food for thought for hikers wanting to lighten their load and their impacts.

My goal for Ultralight Insights is to understand, test, and report on new technologies and gear of interest to lightweight and ultralight backpackers. It's a passion after all, so we just plain enjoy talking about it. I hope readers will add their own wisdom and comments, respond to my questions, ask their own questions, and correct me if I get something wrong. Happy hiking! Will

Thursday, March 2, 2017

Men’s Performance Underwear for Hiking and Backpacking

By Will Rietveld

What do you wear under your kilt? Well, that’s a pretty personal thing, ranging from au natural to something with pretty good support. I’m sure some advocate the former, and its very convenient for women, but men have a different sort of need...

I don’t find many articles on this subject, but it’s a valid question to bring up. Should you wear your normal everyday cotton undies, or is “performance underwear” that much better? Maybe you haven’t thought about it that much. So let’s get this topic out into the open, so to speak.

Men’s performance underwear comes in different styles, from shortest to longest: briefs (not shown), trunks, boxers, and long-leg. Brands tested for this article are MyPakage (left) ExOfficio (center), and Saxx (right). I personally prefer trunks and boxers, but I assume each individual has a personal preference.

Since we pay big bucks for high-tech outerwear – jackets, wind shirts, pants, shells, rainwear – why should underwear be any different? Does it matter that much?

It does matter:
  • Don’t wear something that soaks up moisture and dries slowly, so forget cotton.
  • Stay away from thongs!
  • Synthetics are much better for moisture management and quick drying, just like a baselayer top.
  • Wool is good for the cold months, but it’s slower to dry compared to synthetics.
  • Flat seam construction avoids abrasion.
  • On a multi-day trip, you can wash out synthetic underwear and dry it overnight.
  • They have stretch to conform to the body and provide a snug fit.
  • They prevent your bells from clanging against your thighs, in other words they’re supportive.
  • Many have a wider waistband to distribute pressure (but adds weight).
  • You can actually wear them as a hiking short or swimsuit, which makes them multi-purpose.

  • Briefs typically have no inseam.
  • Trunks have a 3 to 4-inch inseam.
  • Boxers have a 5 to 6-inch inseam.
  • Long-Leg styles have an 8 to 10-inch inseam.

A lot of garment manufacturers make performance underwear in a wide array of styles and fabrics, and the inseam length within an individual style varies by manufacturer.


For years I wore cotton briefs before synthetic performance bottoms came out. Then I discovered synthetic briefs by Patagonia and Terramar for backpacking, and found them to be a good improvement. The revelation came for me when I got some Saxx trunks at the Outdoor Retailer trade show to try when the first came out. Their claim is “life changing underwear”. They did, I love them, and have worn them ever since.

Saxx. What is unique about Saxx underwear (and My Pakage below) is they have an engineered pouch at the front that provides excellent support for the male anatomy during active sports, just like a sports bra does for women. Specifically, their BallPark Pouch, Three-D Fit, and Flat Out Seams combine to provide great fit, support, friction prevention. Saxx has numerous fabrics and styles for different seasons and sports, and a range of colors and patterns from mild to wild. I have worn Saxx trunks and boxers and like both of them equally well. In particular, I especially like the Quest 2, which is a lightweight highly breathable summer version. (Saxx photo)

Saxx also has the Kinetic Tight, which is a synthetic calf length tight for active sports in cool weather. They are a combination underwear and tight. I tried these for backcountry skiing on cold days and really like them. I don’t overheat in them as I would wearing wool tights.

MyPakage. This brand came out soon after Saxx, as I recall, and has been well received. Their underwear has a front pouch similar to Saxx that they call “Keyhole Technology”, and their underwear is available in a range of styles, fabrics, and colors, some pretty wild. I have tried MyPakage trunks and boxers in several fabrics, like them just as well as the Saxx bottoms, and favor lightweight breathable synthetics. (MyPakage photo)

ExOfficio. I recently tried ExOfficio Give-n-Go underwear on a 2-week February trip to camp and hike in the southern Arizona Sonoran Desert. ExOfficio does not have the defined pouch technology like Saxx or MyPakage, but they do claim to have “ergonomic support and active fit”. I tested the Sport Mesh version (lightweight and breathable) and Sol Cool version (cooling), both in a boxer style. Although both versions were the same size, the Sport Mesh fit me perfectly and performed well, but the Sol Cool version was too loose and did not perform very well at all. Fit really matters. Interestingly, the packaging does not reveal what the fabric makeup is, but the garment labels reveal the Sport Mesh boxers are 92% nylon and 8% spandex and the Sol Cool boxers are 54% cotton, 42% nylon, and 6% spandex. Overall, the Sport Mesh was a hit and the Sol Cool was a miss.

Saxx and MyPakage offer many versions of their underwear with or without a fly. The flyless version seems to support a little better but the fly version is more convenient. Not a big difference, so personal choice. Both brands perform well for me, and I don’t have any particular preference between the two. The ExOfficio boxers have a fly and don’t have the specific pouch “technology” of the Saxx and MyPakage underwear.

It’s important to size underwear to get a snug-but-not-tight fit, and definitely not loose. Most have a soft stretch to fit a range of shapes and sizes, so most men would wear one size smaller than their regular pant size. I normally wear a size Large in a pant (34-35 waist), but I wear size Medium trunks and boxers.


There are loads of options (brands, fabrics, styles) in the performance underwear category, and it is difficult to test all of them. So this article will suffice as an introduction to the topic and a testimonial to my experiences and personal preferences. Perhaps readers would like to add their testimonial on brands and styles they like.

This reminds me of a story in the book “I Hike” by my friend Lawton “Disco” Grinter: he ran into a foreign hiker on the CDT called Speedo who was pleading for water. Speedo was complaining of “schayfing” (chafing) and needed the water to shave his “durf”, a private area which had gotten inflamed from many miles of hiking. He was in serious pain. Chafing can be a serious problem while hiking a long trail. The solution is to avoid the problem by wearing performance underwear of the types described above, and use Bodyglide as needed.

My personal preference is the Saxx and MyPakage underwear, which have a well-designed pouch to support and isolate the male anatomy so it doesn’t jostle or rub, avoiding discomfort and chafing. I have a slight preference for the trunk style because they are a bit lighter and cooler, but boxers work just as well. Both are a bit expensive at about $25/pair, but well worth it.

Bottom line, if your undies are in a bundle, causing discomfort or chafing, consider switching to synthetic trunk or boxer style performance underwear with flat seams. My personal experience and preference is the brands (Saxx and My Pakage) that have a well designed pouch to support and confine the male anatomy, but there are likely other brands and styles that have a strong following. This is a topic for some good discussion; what works best for you?


  1. I've been wearing synthetic underwear for 6-7 years now. Once I made the change in my outdoors life, I changed fairly quickly to synthetic on an everyday basis. The fact they are cooler and very breathable, kinda keeps them off the radar since you don't really notice or think about them.

    I personally have just bought the cheaper compression shorts in the 6" length at Big Five and been very pleased; usually around 2 oz/pair. I have noticed that the few cheaper brands very in material stretchability and I like those that are less stretchable because they have better support. I could see how a properly shaped cup, like in the Sax or My Package brands would also provide great benefit. Your article me a bit curious now.

    As far as fit, they just need to be basically skin tight so that they move with you. Because of the way my thighs are formed, they rub together just under my package and with the 6" length, I am totally protected from rash. I found the shorter versions, though long enough to be pulled down to provide coverage, to ride up and so I was still susceptible to rash. The 6" length does not ride up on me and is perfect. In this department, YMMV will be very applicable. But moving to a fitted synthetic brief, at least for me, is a non-negotiable. I'll never go back.

    Lastly, they are great swim suits. If I don't want to get my outer layer wet, I just strip it off and swim in the undies. Really, it is no different than women with their swim suits. And the mixed company I go with into the back country has never complained either.

  2. Thanks for your comments Warren. I will check into the 2 oz/pr synthetic boxers at Big Five. I'm heading toward the same conclusion as you -- I like the 6-inch boxers better than the shorter trunks. After I wrote the article, I noticed that the trunks tend to ride up while the boxers don't, and skin tight is needed to hold them in place. Will


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