What Actually Happened: I booked an evening barre class in the middle of the experiment. Earlier in the day I had applied a thin layer of a lightweight tinted moisturizer, a coat of mascara, a hint of blush and tinted lip balm. I generally don't sweat much during barre, so I wanted play it safe. I was also paranoid that people would stare at me if I looked too made-up, so I kept things relatively natural. Since I didn't get super-sweaty, my makeup was still intact at the end of the class. I dutifully slept in my makeup that night, and besides the few whiteheads that popped up during the course of the week, I didn't notice anything out of the ordinary the next morning.

Later in week, I hit up a morning Zumba class at my local gym sans makeup. I've never left a Zumba class without sopping in sweat, and this time was no different. To really ensure I wasn't washing my face, I hopped in my bath when I got home and rinsed off my body but didn't wash my hair (dry shampoo, FTW). I could've totally used a splash of cold water to cool down my face, which did look slightly flushed. This subsided after a few minutes, though, and I went about my makeup routine before going for a walk with my BF.

Image courtesy Christina Heiser

What an Expert Said Could Happen: On the last day of the experiment, I was ready to set myself up for major skin failure.

"Applying makeup over one day of makeup that has been caked into pores and has trapped dirt and free radicals could potentially cause a huge acne flare, cause significant irritation to the skin and eyes, and may takes weeks to recover from," says Marcbein.

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What Actually Happened: I forged ahead against dermatological advice (and my better judgment) and swiped on another coat of foundation (I chose one with SPF 15 so that I didn't feel too awful about not applying sunscreen in the morning), mascara, eye shadow and lip gloss on the last day of the experiment. Not only did my skin look crazy-shiny by midday, my foundation started to pill around my nose. What's more, my lashes felt really dry and my eyes started to itch. I had dinner plans with friends that night, so I decided to take off my makeup in my office bathroom before leaving work. I was officially done with the experiment and was excited about getting back to living my makeup-free life.

Image courtesy Christina Heiser

I'll be real: There are still going to be days when I pass out in bed without washing my face -- and luckily, I now know that if it happens occasionally, the results won't be that awful. Of course, washing your face is always the better option than not doing it. But if you can't summon the energy to use face wash and water, cleansing wipes are a great option, says Marcbein. My faves are Yes to Blueberries Brightening Facial Wipes, $5.99 (and here are some other top-rated face wipes to try). Now if only I could get myself to wash my makeup-stained pillowcase.