The Science of Sweat with Dr. Drew Best
In this episode of the Science of Slink podcast, Rosy is joined by Dr. Drew Best (@shreddy_professor), an assistant professor of biology at Massachusetts College of Liberal Arts. Dr. Best specializes in the study of human sweating. Together, they explore the evolutionary history, biological mechanisms, and practical aspects of sweating, especially in relation to physical activities like pole dancing. They discuss the differences between eccrine and apocrine sweat glands, how humans have adapted to high heat environments, and the genetic and acclimatization factors that influence sweating. Dr. Best offers practical tips for managing excessive sweating, including pre-cooling methods and the use of antiperspirants. The episode underscores the importance of movement in human evolution and biology, making it a must-listen for both fitness enthusiasts and anyone interested in the science behind sweating.
Chapters:
00:00 Introduction and Episode Overview
00:25 Exciting Announcement: Essentials of Slink Membership
01:38 Meet Dr. Drew Best: The Science of Sweating
03:14 The Evolution and Function of Sweat Glands
11:30 Human Adaptations to Heat and Sweating
17:23 Practical Tips for Training in the Heat
18:22 Optimizing Recovery in Hot Environments
18:51 The Role of Electrolytes and Sports Beverages
20:08 Understanding Sweat Loss and Sodium Replacement
22:57 Dietary Influences on Sweating
26:11 Individual Variation in Sweating
28:19 Managing Excessive Sweating
33:45 The Uniqueness of Human Sweating
35:19 Final Thoughts and Call to Action
Links:
Join Essentials of Slink now! Use code “ESSENTIALFOUNDER” for a $5 off discount for the life of your membership (expires Sept 1 2025) https://www.slinkthroughstrength.com/essentials-of-slink-home-pole-membership
Dr. Best’s Google scholar: https://scholar.google.com/citations?hl=en&user=ViuK774AAAAJ
Transcript:
[00:00:00] Welcome to Science of Slink. This episode is so good. I think you're gonna love it. I'm talking with Dr. Drew Best, who is a scientist who studies sweating and we had such a wonderful conversation. It's really changed my perspective on sweating, and Dr. Best shared some great tips about how to handle being too sweaty, including some that I've never heard before. So definitely stick around. I think it's gonna be a fabulous episode, but I'm gonna borrow your ears just for a second. Because, I'm very excited, Essentials of Slink my membership is live. And this is a very lightweight online home pole membership. It is one hour of class per week. You can attend live. You get the recording, you can do both. And it's designed to walk you through a cohesive curriculum. Science backed, you know how raw, I'm a big old nerd about it.
And it's a little bit of a lighter weight option than Science of Strength, which is my full membership, which is six classes a week, which I realize is a lot of classes and not everyone has that much time. And it's also less [00:01:00] expensive. So it will be $45 a month starting September 1st but if you sign up before then you can lock in the launch price of $40 a month. That's US dollars for my international friends. Only until September 1st.
Link is down there if you're interested. If you wanna learn more, check it out. I've tried really hard to build something that I think is gonna be super accessible for a lot of different folks.
Provide you a lot of flexibility but also community, support, structure, just like the feel of being in a studio from your home pole. 'Cause that's really what I wanted when I started as a home pole. So, with that out of the way, I'm not gonna talk your ears off. Let's get into the science. Such a good episode.
I hope you love it.
Rosy: Welcome to the Science of Slink podcast with a very exciting episode. I think y'all are gonna be as interested in this topic as I am as pole dancers 'cause I'm joined today by Dr. Drew Best, Andrew Best assistant professor of biology at Massachusetts College of Liberal Arts, whose specialization is human sweating. And I came across your [00:02:00] work because as pole dancers, we think about sweating a lot because there's, there's really a sweet spot, right? You don't want your hands to be too sweaty or you're slippery, but you want like a little bit of sweat on your body, so you're sticky.
And, you know, it's, it's a, a constant, particularly right now we're filming this in the summer. It's a constant struggle for us. And I was, I had come across a, a discussion about how like sometimes during lactation you'll get lactation from the armpits. And I was like, oh yeah, of course everyone knows that lactation comes from from sweat glands.
And then I thought about it for two seconds and I was like, wait a second. Sweating is not that basal, right? Like, who sweats like some primates, horses. Hippos kind of, but like, dogs don't sweat. Chickens don't, well, chickens are mammals, but dogs don't sweat. Pigs don't sweat. And I think that's all like general knowledge that like most mammals don't sweat.
So for, for cooling down. Mm-hmm. So then where is this like story about sweating and lactation coming in? And then I, I went down a rabbit hole about reading about the evolution of sweat which is of course. Your specialty and how I came across your work. So do you wanna [00:03:00] talk a little bit about what it is that you do?
And then yeah, what is sweat?
Why is sweat, et cetera.
Andrew: I mean, I, I already have a question. I want to hear the story about sweating from the armpit. Sweat glands. So sweat glands, and there's two types are very similar in origin to mammary glands, right? They all start as the same kind of tissue when you're a tiny little embryo, but the differentiate into obviously different types of glands.
So I'm wondering if, is this a common thing or, because I have never heard of that.
Rosy: I genuinely don't know. I was just I ran across someone who was discussing it and it was like a thread online, and so I was like, oh, yeah, that happened to me when I was lactating. Sometimes it comes outta your armpits.
And I was like, huh, that's wild.
Andrew: I did not know that. Okay.
Rosy: Yeah. Oh, well did I feel like I've already made this worth your while, right? This has already been great.
Andrew: Yep. This is great.
Rosy: So, you know, linking sweating and lactation, same types of sweat glands what's going on there? Then if there's this, something that's like, it's what makes mammals, [00:04:00] mammals, but also there's this other thing that is maybe a little bit more human possibly.
Andrew: Yeah, so one thing all mammals do have in common other than lactation is we do all have eccrine sweat glands. So there's two types of sweat glands. There's eccrine and apocrine. Some would argue, I don't know if folks do anymore, but some would argue there's kind of this hybrid type, at least that was back in the seventies and eighties.
But anyway rein sweat glands and humans cover our, pretty much, our entire body surface just about. And the apocrine sweat glands that we do have are pretty much confined to our armpits or axilla, which is a great word in the pubic region. So. Those are, I guess in some ways those are the more primitive sweat glands.
Other other animals have, other mammals have those sweat glands all over their whole body. So you mentioned horses, sweating. Horses actually repurposed those acr sweat glands into glands that are useful for cooling. But for most animals that [00:05:00] have them, including us they secrete a, an oilier sweat.
That really isn't meant for cooling. They're associated with body hair, so actually apocrine sweat glands, they have a duct that empties onto a hair shaft. So the contents of that sweat are, you know, orodrific to make it positive. And, you know, the hair maybe helps to communicate that scent. So in humans, they are now basically relegated to those parts of our body.
But back to mammals. Yeah. So all mammals do have eccrine sweat glands on their hands and feet, and the thinking is that. Those first evolved in early mammals for frictional, gripping, and seems kind of counterintuitive 'cause when your hands get too wet, they're obviously very slippery. Right? And that's mm-hmm.
Kind of what brought you to this topic. But if your hands and feet are just a little bit moist it kind of softens the skin and actually provides more traction. There's been some studies in small animals, small [00:06:00] mammals, that actually demonstrate this, I believe. So the thinking is that that's where those sweat glands started, and they evolved from the same tissue type that, you know, mammary glands come from.
And in primates, in some primates. So there was a split, I'd have to look at my notes 40 million years ago. Might be a good estimate. When what we used to call old world monkeys which we would now, I guess just refer to as African and Asian monkeys split off from other primates like the ones that now live in South America, say the eccrine sweat glands started to spread to the body surface.
Just, you know, moving away from the hands and the feet. Now these don't fossilize, so we don't have direct evidence of that. But if we look at. The descendants of those primates today. So basically African and Asian monkeys, they do have reed sweat glands on their body surface as do apes. We are apes, so we are further descended from that lineage.
But we have [00:07:00] actually not any, any more sweat glands than them, but actually less hair. Right. And with humans, that trend has really continued. Obviously, most of us are far less hairy, not in terms of number of hairs. We actually have. As many hairs per square inch or whatever as, as other apes. But or, and as and as other old world monkeys.
But the hairs are much smaller and we sweat a ton and those is like 40 million years and two minutes. So if you want me to back up, just tell me. But basically with humans, we see at some point in the last, like probably one to 3 million years, we're not really sure when. This explosion of sweat glands on the body surface.
Like earlier primates and our primate relatives now have them on the body surface, but we have 10 times more per square centimeter, which is huge. I mean, anytime you see something change tenfold in biology, there's obviously a really good reason why that evolved. And so for humans it is totally cooling.
[00:08:00] Yeah,
Rosy: yeah, yeah, absolutely. Which I think, i, I think that's probably, especially for my audience, I think that's just sort of like general knowledge. Like that's why we decided to, to cool off, right? Mm-hmm. Yeah. And I think that the, the thing that you mentioned about like helping grip if you're like a little bit sweaty, very much I think is something that pole dancers are familiar with, not just with the hands, but the rest of the body, right?
Like if you're totally dry, you're super slippery. If you're a little bit sweaty, you're sticky. If you're too sweaty, you're also sticky. Mm-hmm. You're also slippery. So. We're really trying to to thread that, that needle sort of all over our bodies. And I think the, the first thing we can take away from this is like, spider monkeys can't pole dance.
Sorry. They're gonna have to get some, some different, different sweat situation to, to make that work.
Andrew: So many things they can't do. And we're just adding that to the list. Yeah.
Rosy: Thumbs up, pole dancing. Those are some other things we can think about. Yeah. So let's talk about that thermal regulation. Yeah.
So you mentioned it's something that arose 4 million years ago. Seems to be pretty like, I'm, I'm just gonna say sort of like in the, the homo genus more, more generally. Why did [00:09:00] we suddenly need to be cooler? I mean, like, obviously in the Anthropocene being able to cool ourselves is a pretty big evolutionary advantage.
But historically, why was that the case?
Andrew: Yeah. So. I mean, lots of animals have always thrived in really hot environments, both hot, humid, and hot dry. I would say especially primates, I mean, primates are, not all of them, but most of them really are tropical species and humans are no different. But most animals, I mean, their solution, one of their ways to stay cool in a hot environment is to just not make very much heat in the first place.
And you know, I like to tell my students, think back to a, a nature documentary you that you saw, you know, the lions hunting the antelope or whatever. When are they doing that? Right? It's actually probably not the middle of the day. That stuff is usually not happening then it's too hot. And any movement you do, you are increasing the metabolic rate of your muscle.
You're generating a lot of heat as a byproduct. So to answer your question, why did humans suddenly need to start cooling [00:10:00] off way more than primates that came before us, probably because we started moving more, and it's a bit contentious as to exactly when and why, but I think it's pretty safe to say that by 2 million years ago, or a million and a half years ago with Homoerectus some, which is probably a direct ancestor of our species.
From the neck down, they looked almost exactly like us. So they had bodies that were built well for moving long distances and for cooling off like a pretty good surface area to volume ratio, right? So we've got long, slender limbs fairly slender torso. So relative to our body volume, we have a lot of skin, nearly naked skin covered in sweat glands that can get wet and evaporate that heat off.
So it probably had to do with movement, you know, and I'm, I'm fairly enamored with the very difficult to test hypothesis, admittedly, that humans were using a mixture of walking and running to acquire food. And, you know, all of that [00:11:00] movement requires getting rid of heat. I mean, you really cannot perform.
Any, any sport, any activity very well, if you're not able to dissipate heat, and there's an additional idea that maybe humans were, were exploiting a new ecological niche by doing this in the, in the heat of the day when almost no other animals can. So if humans are more active during the heat of the day, we're less, you know, susceptible to being eaten by something and we're better able to maybe hunt down something that can't cool off as well.
Rosy: And I, as I recall, there's also some evidence about that because modern humans can, with exposure to movement during heat, actually find like fairly short term adaptations in sweating and thermo regulation. Do you wanna talk about that a little bit?
Andrew: Yeah. Yeah, so I mean we, it's funny, I was, I was thinking, I think today on my bike ride, it's really hot here today.
I'm in the northeast US, it's like 95 and humid, and I was out in the woods, but it was still really hot. And, you know, we [00:12:00] can acclimate really well. You can go from really not being able to tolerate heat at all to being able to do your full three hour workout in the heat, but there's always a price to pay.
We are still so limited. We're really good at this as compared with other animals, but we're still so limited. I mean, I was a mess for the first hour after my mountain bike ride today. I've, I've had probably half a gallon of Gatorade, you know. So how much can we acclimate? You can. Almost double I think increased by maybe 50 plus percent your sweat rate.
So that's one of the first things that happen. So like, let's say, let's back it up a few months, summer starts, you haven't been getting yourself very hot. Maybe when you exercise it's really cold, or you haven't been exercising, whatever, and now you're outside in the heat and you're exercising, you're, you're, you're making heat that you have to get rid of and you're absorbing heat from the environment, especially the sun.
This is a real problem. You have to keep your body temperature really within like four degrees Fahrenheit or you start to cook. That's really [00:13:00] it.
So first of all, your body detects your kidneys, detect that you're getting really dehydrated.
So you are going to make some hormones called aldosterone. That are gonna help you to conserve more water and salt in your urine. So right away your urine gets darker and it should actually get less salty as well. You should be retaining more water and salt and your body's basically saying, this idiot is gonna keep getting dehydrated.
Let's try to conserve as much water and salt as we can in our urine. And that happens within a couple sessions, right? So a couple days in the heat, you're already getting better at conserving water and salt in your urine. You are getting better. I, this is really all within the first week, week to two weeks.
All these things start happening. Your body is responding more quickly to increases in both skin and core temperature. So you have some thermal receptors in your skin. And more importantly probably you have thermal receptors that are detecting very tiny changes in blood temperature. And blood [00:14:00] is, I mean, it has a lot of jobs, but one of them is kinda like the coolant system of your body.
It is a liquid, obviously, so it will really easily absorb. Any heat that your body makes and move it all around pretty efficiently. So something like a, I actually have notes here somewhere. Something like a 0.01 Fahrenheit temperature increase or something. Yeah, 0.02 degrees Fahrenheit. Temperature increase of your blood.
The thermo receptors can detect that and they will tell your hypothalamus, Hey, body temperature somewhere is going up already, so let's start sweating. So basically the onset of sweating during heat exposure will happen more quickly as you acclimatize. So you might notice by the end of the summer you start sweating right away.
I mean, not to be gross, but I can't get in the car by the end of the summer without, you know, I get up in the seed sweat, you know, I've been in the car for two minutes. My body knows right away. Start sweating. Let's see, some other things. If you continue, if, if you really exercise in the heat too. So if it's not just a thermal [00:15:00] challenge, but you're really getting super dehydrated, not only do you get better at, you know responding more quickly to these temperature exchanges and conserving water.
You also get more thirsty by the way, so you drink more. But you. Basically you have more blood volume. So because you've been sweating so much, now you're conserving all this water That translates to more blood plasma and more interstitial fluid. So that means that you can sweat for longer before you're dehydrated, but maybe even more importantly, it means that your heart can continue to pump the necessary blood around because you're not losing blood volume as quickly.
So every drop of sweat that you sweat out, that ultimately is coming from your blood. So as you sweat, your blood gets thicker and actually a bit saltier. We can talk about this, but you lose more water than you do salt. And that's a real challenge during exercise in the heat because not only do you have to cope with getting dehydrated, but right away your body is sending more blood to your [00:16:00] skin to try to dissipate this heat that you're making.
So from the first minute of exercise in the heat, really the first couple minutes, your heart is pumping blood, not just to your muscles, but also to your skin. So we have this competition for blood flow. So cardiac output has to increase, so this becomes an even more strenuous cardiovascular workout. So we'll see heart rate increase pretty dramatically in an effort to.
Get blood to the muscles and the skin. And so we're gonna have the heart beating faster and probably pumping more per pump. That's called stroke volume. So that's happening right away. So that was a long answer for like, how, how well can you acclimatize pretty well. I mean, you can go from being, you know, like getting really sick in the heat to being able to do your normal workout in the heat, but there are absolutely limits to it.
I mean, there, there's a reason why. You know, in any like sporting event, that's just a simple, like how long does it take to do this thing, right? Like running, biking, whatever. It, those [00:17:00] records are never set if it's over like, well, for running, I mean, records are like under 50 degrees Fahrenheit, just to show the huge impact that that heat has.
So acclimatization has its limits and for a lot of people in the world, unfortunately, in the next couple decades. If if their economies and technology do not permit them to have air conditioning, there's gonna be a lot more heat related deaths.
Rosy: Hmm. Yeah. And I think that's also helpful even like today for, for those of us who are maybe training without air conditioning or are used to training in air conditioning and have a time when you were training without it, right.
So pretty common to do like pole in the park. Right. And if you're doing that and you're used to training. Exercising, even if you're spending your time outside, if you're not exercising at a lower temperature, it's probably gonna be a little bit rougher. Huh. And I think that is a, a normal thing to know.
And also whenever there's a big, you know, heat spike even if you do have air conditioning, if it can't keep up or, you know, you, you just have this sort of general heat stress in your body overall in your days you're, you're moving in [00:18:00] and out. Good to know that it's gonna, you know, maybe plan to reduce the intensity of your, of your training a little bit proactively.
Yes. So that you're not pushing yourself to the point of a heat exhaustion or heat stroke. 'cause that's really you know, as a, as a fitness professional, that's the thing I'm really worried about, right. Is that like you were working out and then that's leading to heat related heat related injury and illness.
Andrew: Yeah. And then if, if you can try to spend the rest of your time in a cool environment so you can recover and, and sleep well. I don't think there's a lot to be gained from being hot all the time. Like you, you want your heat exposure during the workout. Great. Especially if you can't avoid it, but then you have air conditioning, you know you're gonna recover so much better if your body is not also fighting heat illness while it's trying to rebuild the glycogen and all the things that happen after a workout.
Right.
Rosy: Absolutely rest recovery, so important. Right, right. Yeah. I think something else that people may have like run across or are thinking about, particularly when they're sweating is maybe people have heard that like, oh, if you're getting really sweaty, you need sports [00:19:00] beverages, right? You need electrolytes, you need to replenish them in some way.
And overall, I know that. The American diet in particular, I mean, we're, we're both from the US tends to be pretty high in sodium. Other electrolytes, maybe not quite so much, but you wanna talk a little bit about that and just from a sort of physiological standpoint should we all just like, as soon as it hits 80, yeah.
I gotta gotta be out there drinking down the Gatorade.
Andrew: Yeah. So, okay, so my, I love this question. My, my opinion on this is a mix of professional opinion stuff I've read from some of the scientists who've really done the work on this, like FIC and chant from, the US Army Research Center actually the Gatorade Sports Science Institute, even though it's Gatorade, actually has some really good science going on.
So anyway, I haven't done the work on this. And the other thing I'm getting these opinions from is my own experience as a runner and mountain biker. So with that caveat, I think Gatorade is just fine. I've had, I have some friends who are pro endurance athletes and they spend a lot of money on really fancy drinks.
[00:20:00] And I could see the benefit there if you're trying to get carbohydrates as well in your drink. But if it's just electrolytes, a little bit of salt will do. Do you wanna be drinking only water if you're sweating a lot in the heat? Probably not. Especially if it's a long workout. So you're never gonna replace all the sodium that you're losing, all the salt that you're losing during the workout.
That's probably not gonna happen. If it's really hot and you're sweating a lot, you might be losing several grams of salt over a couple hours. Like you're probably, this, this varies between people. I don't think we know exactly how much, but it's roughly one gram of salt lost per one liter of of sweat.
And a liter of sweat. I mean, you might lose a liter of sweat doing your workout in an hour. If it's a vigorous workout, you're probably losing a liter. That's probably a good estimate. So that's a gram. Try to drink a gram of salt. And Gatorade. I mean, actually I have a Gatorade bottle here. Oddly enough, I'm not trying to make an ad for Gatorade.
Any, any drink with like a little bit of sugar and salt. You can make your own. It's going to, it's gonna do the same thing, but this whole [00:21:00] bottle has. About 25% of that. So you'd have to drink, well, you'd have to make this four times more salty to actually be replacing, well, two liters, maybe double as salty and that would taste really disgusting.
But if ou're only drinking water and you're sweating a lot, then there's the risk ultimately of hyponatremia. Which if your listeners don't know, is basically diluting your blood and your body fluids such that the salt content is much lower than it should be. And that usually only happens if you're sweating a lot and drinking a lot of water without electrolytes.
So like for marathons in the heat or really, you know, any kind of event like that in the heat, they really want people to be drinking something with with some salt in it. Even though you're not gonna replace all the salt you lose if you're sweating a ton, you want to have a bit of salt in that. But as far as like, how, how fancy it needs to be, I mean, you're, you're losing only trace amounts of magnesium and, you know, calcium and these and these other, you know, kinds of electrolytes.
Unless you're [00:22:00] going for like a three day ultra event, you don't need to be replacing those during the workout. So you don't need to get a sports beverage that has other electrolytes. You'll get them in your meal. As long as you're eating a varied diet.
Rosy: Yeah. Yeah. And I would, I would hope that no one out there who is listening is trying to do a sustained pole dancing for marathon amounts of time.
The amount of coordination and strength required, I wouldn't recommend keeping up for that duration.
Andrew: I don't know. I mean, doesn't, I don't know. That sounds kind of cool. Just to see if it can be done, you know? Yeah.
Rosy: Maybe, maybe, maybe we'll leave that for the professionals. Most of most of my listeners are recreational pole dancer, so.
Alright. Alright. Yeah, that would be, that would be a lot. Yeah. Yeah. So we talking about. Beverages definitely want to be replacing electrolytes, particularly if you are doing a, a longer training session. I think anyone, especially if you're, if you're doing like a, a camp, right, where you go somewhere, usually those sort of like tropical places and then you're training outside.
Definitely, especially then. But what about other, other foods or things, because I [00:23:00] know that caffeine can increase the, the rate of sweating but are there other things that affect sweating from a diet or nutrition standpoint besides, you know, replacing electrolytes.
Andrew: So in the, I don't entirely know.
So your listeners might wanna do some other research on this based on my answer, but I think in the context of sport, in the context of physical activity, once, once you're physically active, the, the input from your sympathetic nervous system is gonna be way more important in terms of determining your sweat rate, your heart rate, all that stuff.
Then things like caffeine or, you know, anything else in your diet you know, kinda like caffeine does increase your heart rate at at rest. And once you start exercising, I, it's pretty hard to detect the effect of caffeine on your heart rate during exercise. It no longer matters as much. So it's, I would, as, I think it's the same kind of thing with sweating.
Like when you're sweating because you're hot your brain is in charge and it's all based on the temperature [00:24:00] sensing all over your body. It probably has very little to do with any of the stimulants or whatever you've taken as far as diet. So there's been this question as to how much the salt content of your diet actually affects how much salt you lose in your sweat, which doesn't really directly affect sweat rate.
So this might not be super important for your listeners. But the consensus, if there is one that I've seen is, is kind of that. If you have a really salty diet, you might lose a little bit more salt in your sweat simply because whatever is in your blood and interstitial fluid, if it's small enough like salt is, it'll eventually find its way out in your sweat and not in a detoxifying way.
There's no mechanism there where we're concentrating toxins and removing them. That's not happening. But if it's a tiny molecule in your, in your blood or body fluids, it'll get out in your sweat. That said, if you have a really low salt diet. And then you sweat a lot, you're in trouble because then, I mean, again, you could become hyponatremic, but I would say for most of us you know, with a typical American diet and I decently I'm [00:25:00] still getting plenty of salt, right?
So, but I think for someone who's active in the summer, a a. I think a lower salt diet would be more of a concern than a higher salt diet. I mean, some of your listeners could find themselves having to replace several grams of salt, you know, in a day if they're doing a one to two hour workout in the heat.
But that's not a problem if you eat normally because they're salt in everything. Right. Other dietary things. Yeah, I, I'm not really aware of, of any other. Common, you know, dietary attributes that would substantially affect someone's sweat rate or sweating biology during physical activity,
Rosy: So it sounds like the effect size of just, you know, diet or, or drinking or, or supplementation or anything, it's just like, it's just not as big as the effect size of you were physically moving and you're getting your heart rate up and your core temperature up,
Andrew: right?
Yeah.
Rosy: And I know I know a lot of folks who are listening, especially my pots friends. I know you're already really paying attention to how much salt you're getting. And, and making sure you, you [00:26:00] hit that, that minimum threshold. So yeah. I'm, I'm sure for, for some of you, this is, this is good to know.
Also something I think a lot of pole dancers will, will talk about. And it's you know, it's, it, you just notice it more, right? Especially if it's on your hands and feet is individual variation in sweating. So I know you know, some of my students have hyperhydrosis, which is an issue if you were trying to, to not have your hands too sweaty.
So that's I think one, one type of individual variation we know about in sweating sometimes maybe. Potentially pathological and not necessarily within, well, I dunno, I tell us a little bit about individual variation. I, I don't wanna get too, too far down that rabbit hole.
Andrew: I mean, it sounds like you definitely know a lot about this.
So hyperhydrosis from what I've seen in like the dermatological literature is, I mean it's, it's obviously a condition. But it's not super well defined. It's basically sweating sweat too much then is helpful. Right. So it's kind of just on the spectrum of normal variation. So like, yeah, it's normal variation not very helpful for the [00:27:00] people that have it.
Absolutely. So the amount that you sweat is basically a mix of your genetics, and there's definitely a handful of genes that will control this pretty strongly. Probably many others that influence it, that we don't even really know about yet. So it's genetic, and that's obviously random. And it's also your acclimatization, right?
So typically the more acclimatized you become to heat, generally the more you sweat and the less salty your sweat is. So when you start sweating as sweat is made in the coil of a sweat gland it's fairly salty. It's about as salty as your blood and blood is actually pretty salty.
But then as it travels up the coil or up the up the duct and out to your skin, a lot of that salt, most of it is reabsorbed back into the cells of the gland and reenters your body fluids and basically your sweat glands get better at reclaiming more of that salt. [00:28:00] So the amount that you sweat and the amount of salt in your sweat is based on random genetic variation.
Is it totally random? Probably not. I mean, it's possible that, you know, if you trace your ancestry back far enough, you know, you're from a population where there was some like selective pressure for this. Haven't seen any really good evidence for that yet. And it's also based on your acclimatization.
So unfortunately, I, I think I know a question you're gonna ask and I, unfortunately, I think the answer to it is disappointing, which is for my athletes who are sweating too much and it's problematic, what can they do? I actually got this question once before in a very. Different context. I got it from Men's Health Magazine, but they asked it, they said, Hey, the story about how men can sweat less at the gym.
And I convinced them that that was a bad idea for a story. So basically the story is Men's Health Magazine wanted to write a story about how men could sweat less, and I basically said, I'm not really aware of any ways you can make yourself sweat less other than some drugs that block sweating. So basically [00:29:00] drugs for like hyperhydrosis and I also wouldn't really recommend it. I think if your body is sweating, it's trying to cool off and they didn't write the story, they wrote something else, and there might be an answer out there that is useful to your listeners. But other than acetylcholine blocking drugs, which will tamp down the sweat response, I think it would have to come down to things like, you know, mopping the sweat off of yourself with a towel using, you know, wristbands and stuff and headbands.
You can, I mean this, I would not recommend this, but I think you can, you can ablate or basically kill sweat glands with like laser therapy. Right. Which I think some people have done in like their armpits or something. Some like influencers out there and Instagram land or something. Actually I, I think it's done on people's feet.
Yeah, I've heard of it done on people's feet when their foot sweating is a problem. So I got ahead of that question and gave you a really crappy answer.
Rosy: Oh,
Andrew: sorry.
Rosy: I, that's okay. Right? Like I, that's the [00:30:00] sweat is there to help you be alive, which is very important. And sometimes maybe it's not the most useful for other
Andrew: things.
You know what I've thought of one. Hmm. So pre-cooling. So if, if you really wanna sweat less for like half an hour, then right up until you need to do whatever you're doing, wear an ice vest, do something to cool your whole core temperature down and your skin temperature so that it takes longer for both your core temperature and your skin temperature to rise during the activity that will delay the onset of sweating.
So this is done a lot now by endurance athletes. They will, you know, wear a fancy ice vest or in my I actually bought one off Amazon for like 10 bucks. That's a piece of crap. But you just fill it up with ice packs and you wear that during your warmup so your muscles get warm, but your core and your skin stay cool and it is a performance booster in the heat.
But what it will also do, it's what it should do in theory is delay the onset of sweating. Which could be helpful. I mean, there's only [00:31:00] so long that can work. But it, it will work.
There should be other things that might be more actionable. Like even just having an ice pack on the center of your back or like this wouldn't look great.
And I know there's definitely an aesthetic element, you know, like to what you're doing a big one, right? A really big one. But like an ice bandana on your neck. So like a frozen bandana. Some ultra marathon runners do that. And even just cooling off a couple square inches of your skin is enough to keep your core temperature a little bit lower for a little bit longer.
So any way you can do that should, in theory, I haven't seen work on this, but should in theory, reduce the onset of sweating.
Rosy: Might be, might be worth a shot, especially if folks are like, they have a show or something where like, I, I only need to be sweat free for like the four minutes of my act.
Andrew: Yeah, and you can still get your muscles warm if you're wearing this ice vest, but doing your warmup routine you know, keeping that core and skin cool and then ditch it.
And go out there. Yeah.
Rosy: Yeah. That's that's a great tip. Yeah. And listeners, if any of you tried that, let me know. I'd be interested to hear how it, hear how it [00:32:00] goes.
I think the other thing that I know people have mentioned to me that they've used is antiperspirants and sometimes even putting antiperspirants on the hand.
Yeah. Do you wanna talk about that a little bit? Or like I dunno, as a, as a sweat scientist, what are your feelings on antiperspirants versus just deodorants that are designed to reduce theodor?
Andrew: I mean, for the purpose that you're talking about that seems like a good idea. As long as the antiperspirant is not interfering with grip, right? Because that would be problematic. But yeah, I mean, it's the same. So your hands are, are, you know, eccrine glands there's a ton of them on your fingertips, but your armpits, your axilla are actually both. They're apocrine and eccrine glands, but in antiperspirant, as you know, works by actually blocking the duct temporarily.
So sweat can't come out. Right. So yeah, I would say as long as you're not putting it on your whole body and as long as you find that it actually does work on your hands, that's probably a great idea. I mean, the only real danger is if you put it on a big body surface, [00:33:00] then there's a higher risk of overheating.
But yeah, you can totally lose a little bit of your body surface area and still be able to cool off with the rest of it. So I hadn't thought of that, but yeah, of course that would work.
Rosy: Oh, okay. So not, not necessarily a, a thing to worry about. I think there's I think some of the more popular brands people make for like racket sports, like squash, so that you can grip your, your racket without getting too, too sweaty in the hands.
Andrew: That makes a lot of sense. Yeah.
Rosy: Oh, awesome. So that was all the, the burning sweating, I guess questions that I had. But I'm curious if there's something that you just wished that the general public knew about your work, about sweating, about the evolution of sweating just in general, if you're like, man, I wish this were general knowledge, what's the one thing you'd be like. Please know this. Tell your friends.
Andrew: I mean, I think all of your listeners probably get this, but you know, the fact that sweating is one of the ways in which we're super unique, and I think you could probably break it down to like five.
So I'm, I'm a biological anthropologist, and so we would argue there's, you [00:34:00] know, roughly five things that make humans really unique. And that's like big brains with like the language and culture that comes from that. That's obviously a super human thing. But physically, you know, walking on two legs, having very little body hair and sweating and that's, you know, that's kind of it.
What am I forgetting? Someone's gonna be like, you forgot blah, blah, blah. Yeah, maybe I did. It's been a long day. I'm sorry. But you know, the fact that sweating is one of those handful of things that makes humans so unique and we haven't really thought about it much. Most of us, and actually there's a lot more work that still needs to be done on it.
It just reinforces to me that. Humans are meant to move. And that human movement, you know, being physically active is a part of being a human that you, that you can't, like, remove. It's just baked into us. I mean, otherwise sweating would not be one of these unique things that we do. If we, if our ancestors were not, you know, making a living, moving around in the heat, we wouldn't have this extraordinary [00:35:00] trait.
And so it just reinforces that to be human is to move.
Rosy: Ah, yeah. I am fully on board with that. And of course, you know, movement is gonna look different for different people. Different things are gonna be appealing to your, your big human brain, like your specific desires. Mm-hmm. And how you, and how you wanna interact with your body.
But yeah, I think that's a, a lovely note to end on. So folks wanted to keep up with your work or I guess follow you on Google Scholar and find out when you publish new papers or wanted to learn more. What are some, some things you direct 'em towards?
Andrew: Oh, well, I have, I have a very teaching heavy job.
I basically publish a paper a year. But yeah, check out Google Scholar Andrew W. Best. I used to have a website. I don't anymore. I talk a little bit on my Instagram. It's shred professor. As ridiculous as that is, that's about it. I'm on blue sky, but I don't use it. Nah, don't read my stuff, you know, just get out there and move.
Rosy: I think that's a, a wonderful call to action and definitely, definitely cosign. All right, I'm gonna wrap up the episode here. Thank you so much for joining us today, Drew. I think this was a wonderful [00:36:00] conversation. Definitely come away with some, some food for thought. Thank you so much for joining. Thank you so much to everybody for listening, and I'll see you in the next episode.
