According to Gonzalez, reality star Khloe Kardashian doesn't wear underwear when she works out/screenshot, Khloe Kardashian/Instagram
Exercise is known to be great for the skin: it increases blood flow to all organs - including the skin - and delivers oxygen and nutrients along with it.
But if you exercise with a face full of makeup, you may harm the health of the skin, not help it.
To find out what makeup does to the skin during exercise, researchers from Texas applied face cream to the forehead and under-eye areas of 43 university students.
They left the lower halves of everyone's faces makeup free.
Then all the students ran on a treadmill for 20 minutes.
Too much moisture
"Our hypothesis was that makeup could partially or fully block pores, and since pores are important for evaporation, sweating, and waste removal, makeup would negatively affect skin health," said Suho Lee, a professor in the Department of Counseling, Health, and Kinesiology at Texas A&M University-San Antonio and senior author of The study published in the Journal of Cosmetic Dermatology.
The skin plays an important role in helping the body regulate temperature - especially during exercise, when the heart rate increases and the metabolism increases.
Allowing the pores to expand so that sweat can escape is just one of the ways that the skin releases excess heat from the body.
Using a device that can scan the skin for moisture levels, oil amounts and pore size, the researchers compared the parts of people's faces with and without makeup.
Moisture levels on the makeup side were higher than those on the bare side - and while that may sound like a good thing, it actually indicates a negative effect of the foundation.
"Moisture on the skin is evidence of poor evaporation, so a lot of moisture on the skin is not a good sign, as it needs to evaporate," says Lee.
People's pores were also smaller in the areas where they wore makeup, indicating that the skin wasn't able to open up and properly regulate moisture and remove oil and debris as it normally does, Lee says.
Practice Natural/ShutterStock
Sebum levels - skin fat - were also higher on the sides with make-up compared to the sides without make-up.
Sebum is a marker of the accumulation of debris, dirt and bacteria on the skin, which can contribute to conditions such as acne.
The findings also raise questions about other products people apply to their faces, such as sunscreen that is meant to act as a barrier to the skin against UV rays.
With the help of dermatologists, Lee hopes to expand the research to include other types of foundation that contain different ingredients — such as oil-free formulations — as well as sunscreen to determine what they do to the skin during exercise.
More on the same topic:
capacity
Exercise
makeup