Scrolling through our social media feeds, it's not surprising to see our female BFFs and fitness influencers posting workout selfies while—yep—wearing makeup. We understand wanting to hide a daunting pimple or two, but going for a run or hitting the gym in a full face of makeup doesn't seem like the greatest idea for your skin. After all, can a layer of product really allow your skin to breathe as you sweat through your favorite class?

But,what if you work out on your lunch break (we applaud you) and don't want to remove your makeup just to reapply it an hour later? Is it that bad? Well, our experts really, really want you to think twice. Here, dermatologists explain why exercising in makeup is a huge no-no. 

Exercising causes blood vessels to expand, increases blood flow to the skin, and opens pores. Sweat and bacteria get trapped under layers of makeup, preventing the skin from dissipating heat properly and leaving it prone to pore-occlusion (or becoming majorly clogged!), explains New York-based dermatologist Rachel Nazarian, MD. "The trapping of bacteria and sweat in the (now dilated) pores can enlarge pores over time and cause blackheads, while the trapping of heat can flare temperature-sensitive conditions such as rosacea, ultimately causing redness and uneven skin tone," Dr. Nazarian adds. Bottom line: makeup covers up our sweat glands, which can clog pores and lead to acne or irritation, which is just so not worth it. 

Although the goal is not to exercise in makeup, sometimes we are crunched for time or simply forget to take off our foundation before spin class (hey, it happens). For situations like this, it's important to keep in mind that not all makeup is created equal. Dr. Nazarian tells us that if you have no choice or time to remove and reapply makeup when squeezing in a quick lunch workout, use makeup labeled as "non-comedogenic" (won't clog pores) and stick to lighter powders as opposed to heavy oil-based liquid makeups. And if you do wear makeup during a run or class, be sure to wash your face immediately after with a gentle cleanser like unscented Dove Sensitive Skin Body Wash ($6; amazon.com) or Cetaphil Gentle Skin Cleanser ($14 for 3; amazon.com), Dr. Nazarian suggests. We also like these Cetaphil Gentle Skin Cleansing Clothes ($17 for 3 packs of 25; amazon.com), which are perfect for stashing in your gym bag to make the process even easier.

If you do have to wear makeup to the gym, keep your movements light so you won't be dripping in sweat. But if you're religiously wearing makeup during your workouts to conceal pesky breakouts or uneven skin, try switching over to a tinted moisturizer or a CC or BB cream, since they are usually very light, says Debra Jaliman, MD, a New York City-based dermatologist. "Tinted products can add that hint of color and give you that glowy look without the use of makeup," she says. For those who want to cover up acne or blemishes they're insecure about, Dr. Jaliman suggests dabbing on a small amount of spot concealer instead of a heavy foundation.

At the end of the day, dermatologists agree that the best thing you can do for your skin is to completely remove makeup pre-workout. All. Of. It. Even seemingly minor threats like your perfectly winged eyeliner, mascara, and lipstick need to be wiped clean. "They're likely to smear and smudge during a vigorous workout, and can clog delicate pores around the eyes and mouth, leading to styes of the eyelids and blackheads around the lips," says Dr. Nazarian. 

Want to break the dirty habit of sweating it out in a full face of makeup? We've got a couple of hero products that make cleansing on-the-go way more manageable. Our beauty editor loves Sweat Skin-Balancing Cleansing Towelettes ($18; anthropologie.com), which contain ingredients like coconut water and green tea to help quickly refresh and revitalize your skin pre- and post-workout. Plus, they're individually packaged, so you can just throw one in your bag and forget lugging around an entire drugstore of products. St. Ives Glow Apricot & Manuka Honey Cleansing Stick ($8; amazon.com) is another easy and portable option—just dampen skin, massage  face in circular motions with the stick, and rinse. You'll never worry about spillage or a sticky situation in your gym bag.