How to Sweat Like an Olympian

Have you ever felt embarrassed by the need to carry a towel, or even a fresh shirt, with you during the most sweltering months of the year? You shouldn’t. Sweating is one of the most remarkable ways our bodies protect themselves when the mercury heads north.

With summer temperatures spiking around the world as the sweat-filled Olympic Games begin in Paris, we’re joined by Sarah Everts, a Smithsonian contributor and the author a marvelous book called The Joy of Sweat: The Strange Science of Perspiration. She explains why the body’s thermostat is so ingenious, and how it cools athletes—and the rest of us.

Plus: A series of snack-sized anecdotes about the Olympics!

A transcript is below. To subscribe to “There’s More to That,” and to listen to past episodes on the complex legacy of Sojourner Truth, how a new generation of high-end West African restaurants is revealing the roots of “Southern” cuisine, why Colombian conservationists are now trying to sterilize the hippos descended from drug kingpin Pablo Escobar’s personal menagerie and more, find us on Apple Podcasts, Spotify or wherever you get your podcasts.

Chris Klimek: I want to tell you that I received this book as a gift before you were ever a prospective guest on our show, because of my incessant commentary of my own effusive sweating via social media. Someone gave this to me and said, “If I’m the first person to give you this book, then your other friends have not been paying attention.” So thank you for writing this and making me feel seen.

Sarah Everts: Well, thank you for being a fellow sweater who doesn’t actually seem to need a perspiration pep talk.

Klimek: Yeah, well, I just turned the thermostat up to 74 to keep the HVAC from kicking on and ruining the recording, so I’m prepared. I have a towel here. I have water. I’m ready.

Klimek (narration): Sarah Everts is the author of The Joy of Sweat: The Strange Science of Perspiration. While many people may be embarrassed by their sweat, Sarah says we should embrace it.

Everts: We all sweat. It’s keeping us alive. We should stop worrying so much about it and stop being humiliated by it, and move through life being a little less perplexed by the fact that we all are probably sweating right now.

Klimek: Sarah even says that sweat defines us.

Everts: Evolutionary biologists count sweating amongst the characteristics that make us human, and, in fact, they’ll go as far as to say that it’s one of our distinguishing features that set us apart in the animal kingdom. And then also, I write a lot about chemical communication between animals, like pheromones, and it begs the question: Do humans also communicate with smells? Do we find love in the armpit?

Klimek: From Smithsonian magazine and PRX Productions, this is “There’s More to That,” the show that can stick the landing to bring you solid gold history, pop culture, science and more. In this, our Olympics episode, we’ll tell you everything we know about sweat. Plus, some Olympics-themed trivia to bring to your watch parties all throughout the Games this summer. I’m Chris Klimek.

Klimek: Hi, it’s Chris. I hope you’re enjoying “There’s More to That.” We hope that our episodes are giving you a sense of what the world of Smithsonian magazine is all about, and we’d love to hear from you what you think of this season. More importantly, we want to know what you’d like to hear more of. Your input is key. If you have the time to help us design our future episodes, please take this survey. You can find it at smithsonianmag.com/podcastsurvey. We’ll also put a link in our show notes. It should take about five minutes. Thanks again, and as always, thanks for listening.

Klimek: What are some common misconceptions about sweat that you’ve encountered?

Everts: Oh, my God, there are so many. Let me count the ways. Probably the No. 1 misconception about sweat is that it is a detox, that when we are sweating that we are actually getting rid of bad stuff, and that is absolutely not the case. Effectively, our salty floods come from our blood, so when our body gets an overheated cue and starts to freak out that we might overheat and die, it tells our sweat glands to open up and ascend liquid to the surface of our skin, and our hot bodies evaporate that liquid up and in that process cool us off. We’re effectively dumping body heat into the atmosphere.

But where does that come from? And it turns out it comes from the liquidy parts of your blood. So your body makes a decision when you’re overheating that it is wiser to cool down than to keep the liquid in your blood. What it does is it filters out all the red blood cells and the immune cells and the platelets, all the big stuff, and sends all the liquidy stuff to the surface. And so it’s much more than just salt and water—it is sugar and glucose, stuff that you need. It’s vitamins, it’s hormones. It’s also some crap stuff that your body wants to get rid of, like urea or lactic acid. But it’s everything, everything is coming out in your sweat that is actually in your blood.

And if you were in fact to detox by sweating, if the purpose of sweating was to get the bad stuff out of your blood, then you would literally have to sweat out all of the liquid in your blood. That would leave you dehydrated and most likely dead. And so instead, what your body does is it filters your blood using kidneys and then takes the filtered crap out and sends it out in urine. And really when you’re sweating, all you are doing is trying to cool down, and so anything that comes out is just incidental.

Klimek: So if our bodies could not cool themselves through sweating, what would happen?

Everts: Oh, we would die. Heatstroke is a terrible way to die, and in fact, humans are unique in the animal kingdom practically by using sweat as a way that’s super efficient at cooling down. And it’s super efficient because we are naked, we are known as the naked ape, which means we have a huge real estate of skin to evaporate that wet heat up into the atmosphere.

If you think about the places where you have hair, water doesn’t evaporate really well off of hair or fur, and so most other animals that have fur, including humans’ closest evolutionary neighbors, the chimps, they cool down by evaporating water off of naked areas like their tongues. So effectively a chimp will pant just like a dog to evaporate the saliva off their tongue to take the body heat out into the atmosphere that way. We’ve got so much more area to cool down.

Klimek: How much does the average person sweat? Is there a range that’s considered normal?

Everts: What is normal? There are the extremes. The extremes are when you don’t actually have sweat glands at all, and those folks generally are born with a slight mutation in a gene that effectively means they don’t have any sweat glands. That can be really brutal. They have to be enormously careful not to die of heatstroke. Then you have folks on the other side of the spectrum, folks with what’s called hyperhidrosis, which is extreme sweating, and that level of sweat is: You can’t even hold something in your hand without it slipping out because you’re so wet. So it’s hard to hold a pencil, it’s hard to hold a cellphone. And about 15 million Americans have hyperhidrosis.

And then all the rest of us are in the middle. There are some folks who really annoyingly seem to have very little drips of sweat coming down. I say this as a super sweater. And then you have folks like me, possibly you, that the moment it gets hot, you’re just pouring. That normal range is dictated by two things. Unsurprisingly, nature and nurture. So genetically, some families are a little sweatier, and it probably means that they have a slightly higher number of sweat glands on their body. Most humans have between two and five million sweat glands, so maybe you’re on the five million side.

And then also there’s this nature side. You can blame your parents for this, as you would blame the genetic side. It’s where you spent the first years of your life. When you’re born, you’re born with sweat glands, but they’re not very active. It takes until the toddler years before your body really susses out the environment in which you live and how much you really need to sweat in order to maintain your optimal body temperature. So those first early years of your life, your body is figuring out the climate that you live in and figuring out those sweat rates, like how much to release.

Klimek: Why do we sweat even when we go for a run in the cold? How does the external temperature affect our body’s efforts to regulate our internal temperature?

Everts: I think your body learns from its history. Even when you run, your core temperature is getting hotter. Even if your extremities feel cold, the inside of your body is effectively heating up. And so your body just thinks to itself, core temperature rising, need to sweat. That’s the primary reason.

Also, we can start to sweat for other reasons. Those floodgates open based on adrenaline. So sometimes, if you’re scared and it’s maybe not even hot outside but your hands get clammy or your armpits get wet, and although we don’t know specifically why that happens, many people have speculated that if you think about it in the heydays of our history, if you are scared, typically that means there’s a predator or maybe a warring party that is trying to kill you, and it would behoove you to run very fast. And so your body’s likely figuring out from stress that you’re about to exercise really hard, and so it’s probably a smart thing to get the cooldown started pronto.

Klimek: This is a question for Washington, D.C. summers: Do higher-humidity climates make it harder for sweating to accomplish its biological function?

Everts: Absolutely. It’s actually very similar to when you cook down a sauce. If you’re trying to make a réduction, as the French would say, you use a small amount of heat on your saucepan to effectively evaporate the liquid water up and out into the atmosphere. And as you notice, stuff gets left behind in your reduction, and if you’ve sweat a lot, you notice that you can have a salty residue on your skin.

The same sort of thing is happening in that your body heat is evaporating the liquid sweat up into the atmosphere, and that evaporation process consumes energy, it needs heat to happen. And so effectively what your body is doing is it’s using your body heat, which it wants to get rid of, to evaporate those water molecules up and out into the sky.

Now, if it’s super humid out there, there is no more room for water molecules to go up into the air. So you can sweat all you want, but there’s no room in the air around you for those water molecules to evaporate away. And so yeah, humid circumstances are actually really hard and dangerous for folks to cool down.

And the converse, a very arid, dry environment, where sometimes you can be really hot but it doesn’t feel like you’re sweating at all, you’re just so dry, when in fact you’re actually sweating a huge amount. It’s just that it’s so dry out there that the evaporation happens so quickly, which is why in arid environments you’re recommended to wear loose clothing. That’s actually to save water and reduce the amount of water you need to drink, because by having loose-fitting clothing, you create a little subtropical environment that has higher amounts of water molecules nearby, so it doesn’t lead to the fast evaporation of your sweat—so fast that you are dehydrating far quicker than you need to be.

Klimek: Is sweat inherently fragrant?

Everts: No. Up until now we’ve been talking about one kind of sweat gland, but there is another. We’ve been talking about eccrine glands, and these are the sweat glands that are responsible for cooling you down, and they are sourced from the watery parts of blood.

The other kind of sweat gland is called the apocrine gland, and it shows up in armpits at puberty. In fact, it shows up anywhere that you grow hair at puberty. And its sweat is not salty or watery at all. It’s kind of waxy. In fact, it’s probably more chemically similar to earwax than anything else. And it doesn’t actually have an inherent odor when it emerges from your armpit pores. What it is, though, is a delicious food for the bacteria living in your armpits, in particular corynebacteria, and it eats that waxy sweat and then metabolizes it into stinky odors. “Metabolize” is kind of like scientific jargon or euphemism for “poop” or “fart.” So effectively the reason you stink is not your fault—it’s the fault of the bacteria living in your armpits.

That being said, sometimes there are other odors that come out in sweat, that liquidy, salty part. What comes out in the cooling-down sweat is anything that’s circulating in your bloodstream. So if you’ve had a hard night of drinking or a hard night of hummus, you might smell like garlic or you might smell like alcohol, and that’s because your body is digesting it, there’s all sorts of things circulating in your blood, including the smelly molecules that are inherent to garlic and alcohol.

So yes, sometimes your salty floods do have an odor to them, but the vast majority of human odor comes from these apocrine glands that are in your armpits.

Klimek: Does sweat play a role in how humans perceive one another?

Everts: Oh, absolutely. There’s all sorts of nostalgia associated with smell. I think we’ve all had the experience of walking into a place—maybe it’s our hometown, maybe it’s our grandmother’s house—and having a very strong reaction, maybe positively, maybe negatively, to a certain odor.

But the thing that most folks are interested in is: Are we sniffing out our mates? Are we using noses to detect a date or a partner? And there’s all this really interesting evidence to suggest that we do. Probably the most famous one is a T-shirt study from a guy named Claus Wedekind, who gave men T-shirts to wear. And then he took those T-shirts and he gave them to women to sniff and asked the women to effectively rate the ones that smelled good to them.

At the same time, he took blood samples from everybody. And what he found was that the women found men more attractive from that T-shirt odor when the product of a coupling, i.e. a child, would have a really good immune system. So effectively humans, or at least women, find men more attractive if we’d make a baby with them that would have a strong immune system. Unfortunately, that is not very sexy at all. That’s very functional, which, of course, is actually how evolutionary biology typically works, is it behooves us to make babies with somebody where those babies are going to survive. And again, throughout human history, we have been troubled by plagues, we’ve been troubled by infections, and so that’s a really smart thing to pick as an identifier for the person you’re going to mate with.

I’d also like to point out that most of this research has been done in super heteronormative circumstances. And so the greater diversity of how we smell and how that leads to coupling has unfortunately just been in male-female couples.

Klimek: Well, we’re talking about all this information that gets conveyed through scent and how it may or may not draw people to one another, so when did people start using deodorant?

Everts: It’s funny, because almost a better question is when did deodorant and antiperspirants get invented? Because they were on the market for decades before people started using them.

They start coming on the market at the end of the 1800s, and they’re coming on the market because it’s the same time when a lot of antiseptics used in medical applications are coming in, and some doctors are like, “Oh, if we’re using this to get rid of odors on kitchen tables or medical surgery tables, why don’t we put them in a place where it’s really stinky, namely, our armpits?”

Deodorants are pretty much just antiseptics with a bit of perfume, and what they do is they kill the corynebacteria and other bacteria in your armpit that would eat that waxy sweat and turn it into stink. And then there’s antiperspirants that do a slightly different thing. Instead of killing the bacteria living in your armpit, they block all the sweat pores, effectively cutting off the food supply to all the bacteria that would eat your sweat and make you stinky.

These two kinds of products are around from the 1800s, but it’s not until about the late 1919s where it really takes off. And that’s thanks to a product called Odorono and a woman who really, really, really wanted her product to take off.

Klimek: Edna Murphey was the daughter of physician Abraham D. Murphey. Abraham invented a product to keep surgeon’s hands from sweating during surgery. Edna found it was also good for armpits. She began selling Odorono in 1912 and launched a big national advertising campaign a few years later.

Everts: It was still the Victorian era then, and most folks were like, it’s fine enough to use soap and water and bathe and then add some perfume. That was, over human history, pretty much how humans have controlled our B.O. Instead, she was trying to argue that they needed to be using these products to further control their body odor, and nobody was buying it. Also, people were embarrassed to buy things to control body odor. And so she hired a former traveling Bible-salesman-turned-copywriter, and he came up with this really brilliant strategy of not arguing that people just needed to buy this product because it was a great product, but he put the fear of stink in America.

Klimek: That copywriter, a man named James Webb Young, found there was a lot of money to be made in making people embarrassed of their sweat.

Everts: He first started targeting women and said, “Listen, ladies, you think that bathing is enough, you think that perfume is enough. You think that you’re going on dates and that everything is going fine, but actually it’s not. There’s a problem: The problem is that you stink. And, worse than that, you stink and people are talking about you behind your back, especially the men who you would seek to date and to marry. And, frankly, if you don’t get control of your body odor, you’re not going to find yourself a man or a husband, and you’re going to be stuck in social isolation forever.” And it worked!

Klimek: Odorono sales skyrocketed. And once every woman owned some, the company turned its attention to men.

Everts: Late ’30s, early ’40s is when there’s a massive economic crisis, the Great Depression, and so the marketing strategy is pretty much, “Dudes, you think you have a job and that your job is secure, but when you come into the boardroom stinking like a farm boy, you are going to lose your job, and then your whole world is going to come crumbling down. So, don’t let that happen—use our products.”

Klimek: Wow. So what were those first antiperspirants like? Are they chemically different than what’s sold now?

Everts: Yes and no. The deodorants, the ones that were antiseptics, they used all sorts of weird things like formaldehyde, which is a bad idea to put on your body in any amount. But they’re also using things like zinc oxide, which is actually something that we use for diaper rash and also still is used in some natural deodorants. It kills bacteria that would make your armpits smell.

But in terms of antiperspirants, things that actually stop you from sweating, that has always been aluminum-based. So Odorono is actually an antiperspirant. It had a form of aluminum in it, and that’s because aluminum forms these little complexes that clog your pores. And these days if you are buying antiperspirant from a pharmacy, it usually has something called aluminum chlorohydrate. So yeah, if you are stopping sweat from coming out, it is always aluminum-based, and that has never been different, it’s just the slight formulation of aluminum that has changed.

Klimek: So is it bad or unhealthy to stop yourself from sweating with antiperspirant?

Everts: It is not a good idea to put antiperspirant over your whole body, because this is the way that your body cools down. There’s been obviously a lot of concern about aluminum as an ingredient in antiperspirants, because aluminum is not a really great metal, it’s a neurotoxin.

However, the earth is full of aluminum. We actually eat a lot of aluminum. It’s in things like spinach. Because it’s one of the most common metals in our mantle, anything that we grow on earth has it in there, and so our bodies, in particular our kidneys, are really good at filtering aluminum out of our system when it gets into our system. I think if you’re using a little bit of antiperspirant on the surface of your skin in your armpits, that small area, I don’t worry too much about it.

Klimek: Well, we’re speaking as we look ahead to the summer Olympic Games. Can we say how sweating affects an athlete’s performance?

Everts: Sure. An athlete in the middle of a competition needs to be at their peak. And so ideally their body has gotten used to the environment where they’re competing so that their body’s not trying desperately to cool them down while also trying to do its peak performance, whatever that is, whether it’s running or jumping.

And so a lot of athletes will actually train in areas that have a very similar climate as the place where they’re going to compete to get their bodies ready to sweat more, when they know they’re going to compete in a place that’s hotter or more humid than where they normally train. Ultimately, they try to do that to get their sweating up so that they can be as cool as possible while they’re performing.

Klimek: Sarah Everts is a journalism professor at Carleton University. She’s a contributor to Scientific American and Smithsonian magazine, and the author of a great book, The Joy of Sweat: The Strange Science of Perspiration. Thank you, Sarah, for a fascinating conversation.

Everts: My pleasure.

Klimek: Since the Olympics only come around every couple of years, we thought we’d take advantage of the 2024 Summer Games and all the reporting on the Olympics we’ve done here at Smithsonian magazine. Here are some rapid-fire dinner party facts to throw out while you’re out with friends cheering on Team USA.

Brian Wolly: I’m Brian Wolly. I’m the digital editorial director for Smithsonian magazine. I love the Olympics, and I’ve edited many Olympic history and science and technology stories over the years I’ve been here. But one of the ones that stuck with me the most is a piece we did about the fact that the Olympics used to give out, for 40 years, Olympic medals in the arts. So from 1912 to 1952, 151 Olympic medals were given out for excellence in architecture, music, painting, sculpture and literature.

But the caveat is they all had to be about sports. The guy who created the Olympics, Baron Pierre de Coubertin, had a hard time getting buy-in. No one else really believed that the measure of a true Olympian would be incomplete without recognizing artistry. And he was so worried about getting in enough entries that he actually submitted entries himself, anonymously, to the jury. The art world faced it with a good bit of distrust, and they thought that being a part of the Olympics would sully their reputation. They also didn’t like the idea that they had to create art that had to do with sport.

Jeff Campagna: Hi, I’m Jeff Campagna, and I’m a photo editor at Smithsonian magazine. I always wondered who the first athlete was to grace the cover of a Wheaties cereal box. Maybe Babe Ruth? But it turns out it was an athlete you probably haven’t heard of: Bob Richards, the two-time gold medal winner for the United States in pole vault. He picked up his second medal in 1956 and then had his Wheaties close-up in 1958. Now, you’re probably thinking there were some pretty good athletes doing their thing before Bob Richards. How was he the first to appear on the front of the box? The thing was, prior to 1958, athletes were only shown on the back of cereal boxes, so Bob Richards definitely benefited from this change in policy.

Sarah Kuta: Hi, I’m Sarah Kuta. I’m an online writer for Smithsonian magazine. My dinner party fact is that this year athletes will be competing in a brand new sport at the Olympics. Most people know it as breakdancing, but I actually learned that the people who do this sport prefer the term “breaking,” and they actually find “breakdancing” a little bit offensive.

The athletes themselves are called B-boys and B-girls. The dancers will go head to-head in these dance battles or dance-offs, if you will, and judges will be watching those battles and scoring the athletes on things like musicality and technique. And this is a really big deal, because breaking will be the first dance sport that’s ever been included in the Olympics. It’s actually a really difficult sport.

Joe Spring: Hi, my name is Joe Spring. I’m the digital features editor for Smithsonian magazine. And my Olympic fact is that the only event that will take place outside of France for these Games is the surfing competition, at a spot called Teahupoʻo in Tahiti, which is in the South Pacific and is part of French Polynesia.

This is only the second time in the past 100 years or so where an event won’t be held on the same continent for the Olympics. And so I did a little digging to find out what that other Olympics was and what the event was. And in 1956, I think, in Melbourne, the equestrian events were held in Stockholm, Sweden, because horses had to be quarantined for, I think, six months before they were allowed into Australia. And the Olympic Organizing Committee didn’t want to deal with that, so they just held the events in Sweden.

There are big waves on the coast of France, but not at the time the Olympics are being held usually, so there’s a better chance for good waves in Tahiti during the Olympics.

Megan Gambino: I am Megan Gambino, and I’m a senior web editor for Smithsonian magazine. We might take for granted that transportation signs come in the form of pictograms, not text, but we actually have the Olympics to thank for that. Back in 1972, a graphic designer and typographer by the name of Otl Aicher actually designed more than 150 pictograms for the Munich Olympics. These took the form of stick figures portraying all the different sports, like running and cycling, and also symbols of simple things like stairs and buses and taxis. After the 1972 Olympics, the pictograms went on to inspire sign makers outside the sports world, starting with the U.S. Department of Transportation, which developed its own symbols in 1974. Ten to 20 years out, this style of pictograms spread worldwide, and you can see them on streets and cities all over the world.

Klimek: “There’s More to That” is a production of Smithsonian magazine and PRX Productions. From the magazine, our team is me, Debra Rosenberg and Brian Wolly. From PRX, our team is Jessica Miller, Genevieve Sponsler, Adriana Rozas Rivera, Ry Dorsey and Edwin Ochoa. The executive producer of PRX Productions is Jocelyn Gonzales.

Our episode artwork is by Emily Lankiewicz. Fact-checking by Stephanie Abramson. Our music is from APM Musicound effects from Epidemic Sound.

I’m Chris Klimek. Thanks for listening.