Do You Wear Underwear With Running Shorts? (Why The Liner!)

If you’ve ever tried on a pair of running shorts, you likely noticed that they have a strange built-in underwear system. It’s often a mesh-like fabric that has an elastic band to stay fitted to the body. But it begs the question: Should you still wear underwear with these types of shorts?

The short answer is no, you don’t need to wear underwear with running shorts. That’s because most running shorts will come with that built-in liner and adding a pair of underwear can lead to some noticeable discomfort.

We’ll go over why running shorts have liners and how you can find the right pair for your body type and your running style.

Why Are There Built-In Underwear in Running Shorts?

If you’ve ever tried on a pair of running shorts, you likely noticed that they have a strange built-in underwear system. This is referred to as a liner and it provides a few key functions:

Reduces Chafing

One of the biggest benefits of having a liner in your shorts is less chafing. (Source)

Chafing is caused by skin-to-skin or skin-to-fabric friction and is only made worse with excess moisture (like sweat or water).

The liner helps prevent this chafing by providing a barrier against the skin and helping to absorb sweat.

Breathable Fabric

The liner in your shorts is likely far more breathable than any type of underwear you can wear. The lining is typically made from loose-knit fabric, almost like mesh, which helps promote air flow.

This keeps you cooler and (ideally) less sweaty.

More Comfortable

With running shorts, you won’t have to worry about your underwear riding up into places you don’t want it.

If you’ve ever run with underwear, you likely know this feeling – liners can help you avoid it.

Less Hassle

All you need to do is put on your running shorts. No need to figure out which underwear works best. As an added bonus, you’ll have slightly less laundry to do!

Of course, some people will still prefer the feeling of running with underwear on. Sometimes it can provide more comfort.

You can always experiment with different liner types, shorts, and underwear until you find the option that’s most comfortable for you.

Why Do Running Shorts Have Liners?

The main reason running shorts have liners is to help wick away sweat and moisture in order to keep the body cool. Here are a few other reasons why liners exist (Source):


Liners can help provide support and motion control, especially for those with male genitals. The liner can keep things in place and prevent excess bouncing, keeping you comfortable and modest.

Won’t Ride Up

In addition to the added support, liners make it less likely for your shorts to ride up. This can be a major annoyance for anyone whose hips are larger than their waist. Typically, elastic shorts will work their way up until they can’t go any higher. With liners, there’s only so far they can migrate.

Fewer Layers

Running shorts with liners means one less layer to wear on the run.

If you’re running in a hot environment or tend to get extra warm when exercising, this can be a huge benefit.

It may not seem like underwear would make you that much warmer, but the fabric tends to trap heat which can lead to serious discomfort and chafing.

Should I Cut out The Liner in My Shorts?

If you don’t want the liner in your running shorts, it’s best to buy a pair that doesn’t have it. Cutting it out can lead to excess fabric left behind, which can rub against your skin in an uncomfortable way.

However, if you got a pair of shorts with an unwanted or uncomfortable liner installed, there are ways to effectively remove it :

  • Step One: Flip the shorts inside out and cut straight through the middle (crotch) portion of the liner
  • Step Two: Cut along the inside part of the liner, where it connects to the shorts – be careful to not accidentally cut the shorts themselves
  • Step Three (Optional): If there are any stubborn pieces left behind, take a seam ripper and try to remove the liner from the seams (this won’t work with all liners, so look closely to see if it’s a separate piece or if it’s sewn directly into the seams of the shorts)

Do You Need to Run in Running Shorts?

No, you don’t need to run in running shorts if you hate the feeling of the liner. There are no rules to running (except in some cases, like certain races). Always choose your own comfort over what people say you “should” run in.

That being said, if you’ve never run in a pair of true running shorts before, it can be worth a try. You don’t need to spend a ton of money on the fanciest pair at the running store.

Instead, try less expensive options to see if it makes a difference in your overall comfort. This can be especially beneficial as you start to increase your running distance – the longer you run, the more likely you’ll start to notice some discomfort.

If you do decide to buy a pair of running shorts, you may notice that there are a few different lengths to choose from. Running shorts typically come in lengths ranging from 2 to 9 inches – this refers to the inseam length (Source).

The smaller the number, the shorter the shorts. Longer shorts are great for casual running and chafe prevention, while many runners who race tend to prefer the shorter options. Try a few different types to see how they feel while you run.

Final Thoughts

Running shorts are made to provide extra comfort and support on the run, but they aren’t a requirement for running.

Many runners will have different short material, length, and style to choose from depending on what kind of running they’ll be doing that day.

Like all things, it ultimately comes down to experimentation and personal preference.

Aprill Emig

Based out of Duluth, MN Aprill loves to write about the outdoors, education, and all forms of adventure. You can find her mountain biking, running, or playing roller derby.

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