Getting a good night's sleep (open in new tab) is linked to improved performance and cognitive function. Sleep is also thought to affect appearance, leading to the popular concept of "beauty sleep." (opens in new tab) As an experiment, Greg and Mitch of the Channel decided to stay awake for 36 hours, took pictures every 6 hours, and tracked whether sleep deprivation (opens in new tab) affected appearance. The results were... . were astounding.

"Scientists don't actually know why we look so messed up when we don't sleep," Greg says in the video, citing the two most famous theories in evolutionary biology that might explain it. [The first theory goes like this: when we are sleep deprived, our immune system is weakened, making us more prone to accidents. This weakened state is reflected in your face, causing other well-slept community members to avoid you; the second theory is that sleep deprivation makes you more pessimistic and less adept at expressing your emotions.

Greg and Mitch woke up at 8:00 AM and started their day as usual (except, aside from morning coffee, no caffeine for the entire 36 hours). The first 10 hours or so went well, but Greg, who likes to nap, began to struggle after that.

At 4:00 a.m. (around the 14-hour mark), Mitch feels his cognitive abilities slowing down. He says, "When you're trying to learn or remember something, the part of the brain called the hippocampus is very active and basically takes in all the information and processes it." But when you look at brain scans of sleep-deprived people, the hippocampus is basically nonfunctional. On top of that, the proteins needed to actually build the connections between neurons become unavailable in an overworked state, making it really difficult to even effectively, physically, create memories."

When the sun rises again, they both begin to feel slightly more energized as their bodies try to regain their circadian rhythms. Mitch explains, "As the sun rises, the body begins to release hormones that are attuned to daylight, waking the body up." However, that second wind doesn't last, as adenosine levels rise quickly and the effects of the all-nighter begin to show on the face.

By the end of the challenge, they both looked distinctly different, especially Greg's face, which looked inflamed. 'You look so sad!' He says. 'I'd like to distance myself 100% from the right person,' he says." Mitch also struggles to keep his eyes open, and the wrinkles around his eyes are more prominent, making him look deeply unhappy.

The takeaway from this video is, as one might expect, very simple. Not only to look your best, but also to be your best self (or to go about your day functioning as a human being).

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