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Running Debate: Lined vs. Unlined Shorts

If you're a runner, you probably stand in one of two camps — running shorts with liners, or without. I am firmly entrenched in the 'no liners' camp. My co-worker loves liners. We fight it out.
two men holding up running shorts(Photo/GearJunkie)
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It’s 4 p.m. on a Thursday afternoon and spring is in the air in the front range of Colorado. Along with half the city, I cut out early from work and blast to the trailhead, eager to spin some quick trail miles on my winter-softened running legs.

I park my car in the busy lot, whip off my work pants, and throw my shorts on over my underwear. There is no moment of nudity, no awkwardness. And in one quick moment, I’m tying my shoes and on the trail.

two men holding up running shorts

I’m no prude, but I do try to be respectful of other trail users. And flashing random strangers while taking off my underwear to put on “lined” trail shorts could lead to a visit to the police. Yes, I know I can awkwardly scooch into them inside my truck, or wrap myself in a towel or robe. But why, when nonlined shorts, coupled with great underwear, are just as good for 99% of my runs?

We’ll talk about the other 1% in a bit.

If you’re wondering what the case is for lined versus unlined running shorts, my fellow GearJunkie editor and I go toe to toe — or, dare I say, cheek to cheek — to sort it out.

Running Debate: Lined or Unlined Shorts?

Why I Don’t Like Liners in Running Shorts (Usually)

For some, this may look like the unhinged rant of a madman. No liners? You must be nuts.

Just look at our buying guide for best running shorts, written by someone I respect in the running space. Every pair of shorts listed has a liner. Every. Single. One.

Paths Project unlined running shorts
Sean McCoy loves Paths Project’s unlined shorts; (photo/Mary Murphy)

But my favorite shorts on the market do not have a liner. Made by Paths Project, they are perfect, to me, in every way. Instead of a liner that functions as underwear, I just wear underwear that functions as a liner — read good-quality boxer briefs. Paths Project also makes liner shorts you can buy separately, but to me, quality underwear is ideal.

Boxer briefs are what every pair of running shorts wants their liner to be. Soft, form-fitting, and comfortable for many hours on end, I wear my underwear all the time without a second thought. You probably do, too.

So, why remove it in exchange for a liner that may, or may not, be as nice against the skin? I have trouble with the logic. A good pair of Saxx or other supportive underwear, that you can wear to the office before or after your run, makes sense.

This is how I run at least once, sometimes twice, every day, year-round.

Oh, and let’s not forget the elephant in the room. For half the year, serious runners in cold climates don’t wear shorts. In winter, I continue wearing underwear that works well in the summer, too. That’s because my running pants don’t have a liner. Ain’t no way you’ll catch me running commando in winter. Brrrr!

The 1% Caveat: I Like Liners for Very Long Runs

OK, so I’ve presented a lot of my case against liners here. However, there is one good case for liners — very long runs.

I mention this as “1%” because most runners only run over, say 20 miles, on rare occasions. Sure, there are some high-mileage runners who do back-to-back 20+ mile runs in a week. But even in training for 100-mile races, I rarely top 20 miles on long runs outside of a few very high-mile weeks in the core of my training cycles.

And on those long runs, as well as in races, I often shift over to liners to avoid the eventual chafing that anything but compression-style shorts results in.

And at enough miles — say, more than 50 — for me, there is nothing that will stop eventual chafing. Bring in the Body Glide and apply liberally.

Sean McCoy during the Grand Canyon 100 ultramarathon
Sean McCoy grabs a selfie during the Grand Canyon 100 back in 2015. In this ultra, he mostly wore tights, which were unlined

But to me, that’s the point. No amount of support will defeat the onset of chafing eventually. And let’s face it: For most runners, getting out the door and taking that first step is often the hardest part of training. By removing a small barrier, getting out that door is possibly just a little easier.

If you find that liners are your favorite, go for it. Whatever floats your boat. But if you haven’t made up your mind, or just haven’t had the chance to try fantastic unlined shorts like Path’s Project, I’d urge you to give it a try. You just might become a convert, too.

— Sean McCoy, crusader for the unlined short

Counter Opinion: Lined Shorts Are a Worthwhile Luxury

I like my running shorts how I like my roads: lined. They provide control and guidance.

To clarify, I prefer my running shorts to be lined with boxer-like shorts. They provide support with compression and a next-to-skin layer that can help wick sweat. I’m not saying I need a ton of support but I don’t want my runs to mimic tennis balls in a dryer either.

In contrast, brief-style liners can work on training runs, but the edges of the brief rarely match my anatomy and evoke memories of bad bathing suit chafing as a kid.

Lined running shorts
Lined running shorts; (photo/Mary Murphy)

A seam in the wrong place can prove to be a constant annoyance or worse, chafe so bad it takes days to recover. Going linerless means testing out underwear, even boxers, to figure out which brand won’t irritate me. That process likely involves being annoyed (or chafed) several times.

For some, Saxx is the solution. Saxx started making lined running shorts once it realized so many runners were wearing the brand’s underwear, with its “Ballpark” pouch, underneath other running shorts.

In fact, those lined running shorts helped put me squarely in the lined camp. Other lined short favorites have been made by Smartwool and the more ultra-serious Montane.

The running shorts debate comes down to personal preference. But when it’s time to get serious, purpose-built lined running shorts are the way to go.

Why I Like Liners in Running Shorts (Usually)

Lined running shorts are made for running. Liners have a specialized fit and construction, with an emphasis on wicking, and often have anti-odor treatments as well.

Conversely, random underwear under run shorts can mean sweating against a fabric made for a tough day at the office.

Ultra-distance runners will acknowledge that liners can help prevent chafing and actually garner the benefits of their slight compression.

Personally, there’s something about that snug fit that just puts me in the zone. I change into them and my brain knows it’s time to run.

Note: I usually put on run shorts before driving out to my spot, but yes, I’ve dabbled in that temporary nakedness after a run to put on drier clothes.

On cool-start mornings, the liners hold some heat next to bits I prefer not to freeze. By mid-summer, my concern shifts to staying dry in the same areas, and mesh liners have performed admirably there.

Compression liners often include a smartphone pocket. I prefer a belt to hold my phone. However, as far as built-in pockets go, the liner pockets are infinitely more preferable than the bouncy, one-size-does-not-fit-all phone pockets on unlined and brief-lined running shorts.

With most gear, I prefer compartmentalization. If one aspect fails, you don’t have to replace it all. But with running shorts, the liners should tear well before the polyester or nylon of the outer shell fails.

My Caveats

As mentioned before, I can tough out a 3- to 5-mile run in brief-lined shorts, but the thought of underwear and unlined shorts seems like too many variables and would challenge the way I pack on trips. Does this all boil down to laundry?

I do see a potential laundry benefit in separate layers. A short run in boxers and unlined shorts may mean you send the boxers to the hamper and get away with another run in the outer shorts (in arid climates, at least).

A glaring exception is winter running. That’s when I’m wearing tights as my liner, with unlined shorts over them. Really, it’s a windbreak layer and pockets for stashing gloves in if my hands ever warm up.

— M.T. Elliott, fearless defender of brief linings

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A Consensus?

Our debate here at GearJunkie seems to be about whether or not we run with liners or with underwear. None of us recommend running commando, especially for any great lengths.

Runner In Best Men's Running Shorts

I get that some out there want to run with the least amount of anything on. There will always be someone out on the trails in feather-light shoes, no shirt, tiny socks, and brief-lined shorts. Yet, that’s not where either side, internally, has landed.

Internally, our debate has been more about boxer briefs versus long-lined shorts. Those who have found boxer briefs that remain comfortable on long runs are free to wear a wider variety of simpler, and less expensive, running shorts over their underwear. Those who prefer a built-in liner made specifically for running (or workouts) are willing to pay more for an all-inclusive short and bask in its luxurious performance.

So, which camp do most runners fall into? If the running short market says anything, the vast majority choose lined running shorts. And if trailhead parking lots say anything, most runners are excellent at wiggling into their shorts, undetected, behind the wheel.

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