We humans are a sweaty bunch. Everything from heat, nerves, fever and stress can wring us out like a wet rag. This almost constant state of perspiration left us wondering what sweat actually does to your skin when you don’t wash it off. Turns out, according to dermatologists, sweat is a lot like grandma’s casserole — great right out of the oven, but really not good for you after sitting out for a day.
First, the good: Sweating is one of the most efficient ways your body detoxes itself (way better than that nonsense £1,000 juice cleanse your annoying friend is putting himself through). According to a 2011 study published in the journal Archives of Environmental and Contamination Technology, the act of perspiring excretes a truly nasty mixed bag of toxins, including alcohol, cholesterol and even high levels of sodium. Awesomely, those droplets of salty sweat are simultaneously acting like pipe cleaners for your pores, pushing out any dirt and grime that would otherwise cause you to break out like a hormone-pumped 13-year-old.
There is, however, a catch. Letting that sweat dry directly on your skin allows it to settle back into your pores, complete with whatever zit-causing toxins it carried with it in the first place. What does this mean in practical terms? “You want to hop in the shower or, at the very least, wash your face immediately after a workout or any heavy bout of perspiration,” says dermatologist Anthony M. Rossi. “Or else you’ll be looking at a pretty nasty breakout.”
So, as they say, sweat it out — but also wash up afterwards, for your own sake, as well as whoever you’re about to share an enclosed space with.