By definition, sweat is “a mixture of water, salt, electrolytes, and a protein called urea which is a waste product of protein metabolism,” explains Melissa K. Levin, MD, a New York City-based dermatologist.
That glow you notice after exercise can be attributed to heat capillaries that dilate when you sweat, says Kavita Mariwalla, MD, a dermatologist based in West Islip, New York. “Sweating also activates the production of sebum, a natural lipid-based oil,” says Levin. Both urea and sebum can soften and moisturize the skin, she notes. Urea is, in fact, also a hydrating ingredient in many skincare products.
Sweat also opens the pores, pushing dirt and debris out. “When we exercise, we get a rush of blood to the skin, which carries oxygen and nutrients that can nourish the skin cells,” explains Ashlyn Morris, an area spa manager at Equinox in Southern California. “That blood flood also carries away waste products and free radicals from healthy skin cells to keep skin plump, radiant, and functioning properly.”
Some research even suggests sweat is protective against strains of bacteria such as staph infections and E.coli, Levin notes.
But even though sweat is sterile, it isn’t meant to be left on the skin for prolonged periods of time. “Mixed with dirt, makeup, and pollution, it can accumulate and clog pores, triggering or worsening acne and causing inflamed hair follicles,” says Levin.
Here, four tips to maximize sweat’s benefits.
“When the pores are open, anything that’s on the skin such as dirt and makeup is going to penetrate,” says Sarah Garland, New York City-based senior manager of planning for The Spa at Equinox. Washing your face and body before you sweat can give you a clean slate so there’s nothing bothersome entering your pores during exercise.
If you’re draping your towel over machines or leaving it on the floor, then using it to wipe off, you’re exposing your skin to more germs and bacteria. Always use a clean towel, and, if you’re acne-prone, consider using a cold, wet towel to wipe away sweat, lowering the likelihood of any build up, suggests Garland.
“It only takes about a minute for toxins to reabsorb back into the skin,” notes Morris. Rinsing off immediately post-fitness helps ensure sweat (and anything it mixed with on your skin) doesn’t return to the follicles and cause congestion, she notes. Take a cool shower or rinse with cold water; lower temperatures close the pores and decrease capillary activity which can contribute to redness, notes Garland.
To maintain homeostasis, if you’re sweating water out on a regular basis, you need to replace it. Experts recommend aiming for half of your bodyweight in ounces each day, increasing that amount and incorporating electrolytes when training more intensely.