Self-Care Science: Why it Feels So Damn Good to Pull on Your Sweatpants

It all boils down to the fibers, man.


We mostly all agree that hot tubs, massages and the like feel good, but ask anyone why and you’ll get a shrug (which is fair! That person was trying to relax, after all). Understanding what these self-care activities are doing to your body — and more importantly, why they feel so good — can actually help you reach peak relaxation, though. That’s why we’re looking at the science behind various feel-good pursuits. Today’s focus: Putting on sweatpants.

Sliding into a pair of sweatpants feels nice for several reasons, the most obvious being that cotton — the material most often used to make them — is a natural fiber and soft by nature. “The cotton fabric is much more breathable and is a natural fiber, which is good for wicking away moisture,” dermatologist Anthony Rossi explains, adding that silk (if you’re the fancy lounging type) is also a natural fabric.

The nice thing about cotton and similar fabrics is that the natural fibers they consist of have much more space in between them than the fibers that generally make up synthetic fabrics, like polyester. Since polyester fibers, for example, sit relatively flush against one another, more fabric rubs against your skin while wearing polyester clothes, which inevitably equals more irritation. With cotton clothes, the extra space between the fibers creates less contact with your skin and allows for more airflow, both of which contribute to the cushion and feathery feel of them.

Likewise, as Rossi already mentioned, that extra space serves to keep your temperature regulated and reduce any uncomfortable sweating. Since cotton is a natural fiber, it absorbs moisture, keeping it away from your skin and reducing your chances of developing any unpleasant, moisture-related rashes. Synthetic fibers, on the other hand, tend to repel moisture, which means rather than absorbing sweat and holding it away from your skin, all that grossness builds up on the inside of the garment.

Another perk of cotton absorbing moisture is, when you sweat while wearing cotton sweatpants, some of that sweat soaks into the fibers, cooling the air that flows through them on hot summer days. Gross, I know, but at least the sweat isn’t just sitting on your skin, like with synthetic fibers. Plus, if you give yourself and those sweatpants a good wash after sweating in them, your skin should be just fine.

Speaking of sweating, in the hot summer months, that space between the natural cotton fibers acts as a barrier against the heat that accumulates on the surface of the fabric. As I explained earlier, synthetic fibers tend to sit more flush against the skin, so when the sun heats them up, your skin heats up, too. But since natural fibers leave more space between themselves and the skin, when they heat up, your skin gets less of that heat. Meanwhile, in the winter months, that same open space between the fibers can retain at least some of your body heat, keeping you warm and comfy.

In those cases, heat is a good thing — as I wrote in our scientific exploration of why steamy showers feel so good, “heat is just plain reassuring.” This could be because, as some studies suggest, heat activates the parasympathetic nervous system — sometimes called the rest and digest system — slowing your heart rate, increasing your intestinal activity and relaxing your sphincter muscles. Chill!

What’s not so chill, however, is that tight clothes, like certain jeans and briefs, can compress the nerves in the thighs, causing pain, tingling and numbness. A loose pair of sweatpants, on the flip side, is much more comfortable for obvious reasons. Not to mention, eating in a pair of pants that presses up against your abdomen can trigger heartburn and acid reflux, “particularly and especially when somebody overeats,” reflux specialist Jamie Koufman warned Everyday Health. So you can see how sweatpants would help when you decide to eat a day’s worth of calories in one sitting.

Besides being good raiding-the-pantry attire, donning a pair of sweatpants (or no pants) after a long day in your restraining work clothes can help your mind make that important transition from working to relaxing. This is something my colleague Magdalene Taylor recently confirmed when looking at scientific studies (and talking to actual nudists) about why it feels so good to fling off your work clothes the second you walk through the front door.

That relaxing effect can help you sleep, too, a phenomenon “The Sleep Doctor” Michael Breus once explained to my colleague, Brian VanHooker. “You want to sleep in loose-fitting PJs. Clothes weren’t designed to be worn while sleeping, as buttons, zippers, etc. aren’t particularly sleep-friendly,” he said. He also added that cotton in particular is a good choice, since, as we already know, it breathes incredibly well.

Essentially, sweatpants do your body all kinds of good, and because they take such amazing care of you, make sure you do the same for them, too.