Is Sweating Good for You?

What Is Sweat, Anyway?

By the time you feel beads of sweat forming on your brow, your body has gotten the message that its temperature has notched slightly over 98.6 degrees, whether it originated from muscles working to stoke the heat from within or a sauna warming up the surface of your skin. "Sweating is a cooling mechanism that keeps our internal core temperature in a safe zone," says Thad Wilson, Ph.D., a physiology professor at the University of Kentucky College of Medicine, who has done extensive research on sweat. (Wait, how much should you really sweat during a workout?)

Our sweat glands are located one to two levels below our skin's surface — within the dermis and hypodermis layers, respectively — with ducts that travel up to the surface and widen at the end to form our pores. These sweat glands transport salt and other trace substances (more on those later) from the blood and fluid around cells into the central cavity of the gland; it is this salt movement that in turn pulls water into the cavity. "As sweat is released through our pores, it evaporates, thereby cooling the skin." The blood within the just-under-the-surface capillaries is able to offload heat and recirculates through the body, lowering our internal temperature.

"It seems as if we sweat more in our armpits or groin area, but that's because those areas are covered with clothing and not exposed to the air for evaporation," says Patti Christie, Ph.D., a lecturer in chemistry and biology at the Massachusetts Institute of Technology. The apocrine sweat glands in those hot spots also get a lot of attention because (researchers aren't sure why) they also release fats and other cellular debris that bacteria on our skin love to chomp on, creating that unmistakable musky odor. The real cool-down? That comes from eccrine sweat glands, which blanket the rest of our body.

Besides keeping you cool and comfy, is sweating good for you? Here, experts break down the benefits of sweating that'll have you signing up for another HIIT class.

Hydrates Skin

Get this: "We're always sweating a little, whether we sense it or not," says Wilson. "Part of the reason is to make sure the outer- most layer of skin stays hydrated." Within its mostly water-and-salt mix, sweat also contains very minute amounts of other substances found in the fluid around our cells. Two of those are natural moisturizers: urea, which is a byproduct of protein metabolism that's predominately excreted in urine; and lactate, a molecule produced by muscles during intense exercise. Thanks mostly to that urea and lactate content, sweat helps keep our skin supple, says Erin Kil, M.D., the founder of New Bloom Dermatology in New York. "Hydrating our outer layer of skin, the stratum corneum [aka epidermis], is particularly important since it's the final barrier between outside pathogens and our body," she says. "If it gets too dry, it can't do its job as well." (A timely reminder to add moisturizer: Winter air and indoor heating can dry out skin despite this benefit of sweating.)

Fights Off Bacteria

There's also an antiseptic effect to sweat thanks to other trace components within its cocktail. "Sweat contains antimicrobial peptides — cathelicidin, lactoferrin, and dermicidin — that can protect the skin from infections and conditions like acne and eczema," says Dr. Kil. But that doesn't mean that the longer you hang out sweaty, the better off you are. "The antibacterial benefits are meant for temporary protection—if you have a lot of sweat that sticks around for too long, it can become a bacterial breeding ground," she says. When you hit the shower, forgo traditional soap for a sulfate-free wash that cleans without stripping skin. (Showering isn't the only thing you should do within 30 minutes of a workout.)

Improves Workout Performance

The better your body is at sweating, the better it maintains its internal temperature — one key factor in your workout performance. Folks who are fitter sweat more in anticipation of a rise in core temperature and an increased need for cool- ing, says Wilson. "That means they can often exercise longer and more comfortably," he says. The good news is you can train your sweat glands the way you train your heart. "We've done research showing that people who trained on an exercise bike for eight weeks subsequently have improved capacity to sweat," says Wilson. "They improved their fitness 20 percent and their sweating capacity by 30 percent," he says.

Relieves Pain

Got a kink in your neck that won't quit (and no one around to massage it out)? Working up a sweat just might soothe the soreness, experts say. "Exercise stimulates neurochemical pathways in the brain, resulting in the production of endorphins that act as natural painkillers," says James Ting, M.D., a sports medicine physician at Hoag Orthopedic Institute in Irvine, California.

Clears Out Skin

Another key benefit of sweating for your skin: "When you sweat, your pores open and release the grit and grime that has built up inside of them," says Whitney Bowe, M.D., a dermatologist in Briarcliff Manor, New York. Caveat: Don't just sweat and go. All of that dirt from your pores accumulates on the surface of your skin, so aim to wash your face three times a day, especially if you frequently play sports or work out.

Controls Mood

Maybe you've already noticed — before a workout you're on edge, but afterward, you feel like giving everyone hugs and high fives. It seems natural to associate feeling warm with a sense of well-being and relaxation, but there may, in fact, be a scientific explanation for this feeling, says Dr. Ting. "Research has suggested that temperature-sensitive neural circuits to specific regions in the brain exist and may play a significant role in controlling mood," he explains. So the next time you sense yourself being short, take a break for a Bikram yoga session or a run for a get-happy fix.

Prevents Colds and Other Infections

If you've ever wished you could walk around dousing everything in sanitizer wipes to prevent illness, you might be in luck, thanks to this benefit of sweating. A study from Eberhard Karls University Tubingen in Germany suggests that human perspiration contains a naturally occurring antimicrobial peptide called dermcidin, which has been proven to fight tuberculosis germs and other dangerous pathogens, says Dr. Bowe.

What's more, when your body turns on the sprinklers, it's a good sign you're likely raising your core temperature up enough to benefit your immune system. "When your core temperature goes up, your body increases the number of white blood cells," says Christie. Indeed, one reason your body runs a fever during a viral or bacterial infection is because many pathogens' proteins have a lower tolerance to heat than your own proteins, so the spike in heat helps knock out the invaders. (

Regulates Body Temperature

The evaporation of sweat off of the skin prevents you from overheating during an intense workout, says Dr. Bowe. So, what would happen if you didn't sweat? "In extreme cases, the lack of sweat during a seemingly strenuous workout could be due to a condition called anhidrosis that can lead to dizziness, a skin rash, or loss of consciousness during exercise," says Morin.

Lowers Kidney Stone Risk

Research from the University of Washington found that regular exercisers sweat out salt and tend to retain calcium in their bones, rather than having them — salt and calcium — go into the kidneys and urine where stones form. Frequent sweaters also tend to drink more water and fluids, which is another stone prevention mechanism.