What's the deal with cold plunges and saunas?

20:47Can you hypnotize someone into sleeping with you?

20:50Emily Oster:I gave her some suggestions to be sexually aroused. Can you get someone to join your cult? NLP was used on me to access my subconscious. NLP, aka Neuro Linguistic Programming, is a blend of hypnosis, linguistics, and psychology. Fans say it's like finally getting a user manual for your brain. It's about engineering consciousness. Mind Games is the story of NLP, its crazy cast of disciples, and the fake doctor who invented it at a New Age commune and sold it to guys in suits. He stood trial for murder and got acquitted. The biggest mind game of all, NLP might actually work. This is wild. Listen to Mind Games on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

21:39Emily Oster:All right, we are back and it's time to talk about you're hot and you're cold. You know, Katy Perry is on my mind this week because we're talking about cold plunges and saunas. both of these things are all over the wellness space. You've got promoters on all sides. As I've explored this, I've seen people making claims from the idea that they're a nice way to relax after a workout to they will improve diabetes control. I mean, it is all over the map. Lots to dig into here. But Emily, before we get started, I feel like we need to just kind of define our terms. Can you walk us through like, what is a cold plunge?

22:22Emily Oster:What is a sauna? All right. So generally, and I will say part of what's hard about this space is that this is not well-defined because really we're talking about a lot of things, many of which are done in the wellness space, which is an unregulated, vague space. But when people talk about cold plunges, they are generally referring to being in a some body of water, largely submerged for an amount of time that varies from like I jumped in the water and I got immediately out to sitting for, you know, five or 10 minutes. The water is generally extremely cold, typically icy. Often people will do this in the like low budget version of this is I've got like a giant backyard, like metal tank.

23:11And then my Instagram video will have me walking out and like cutting a hole in the ice on the top of my tank and then getting into it often with my husband or wife. So we can have

23:22Emily Oster:a romantic popsicle worst date night ever, worst date ever. But anyway, so that's, so it's, it's very, very cold. Of course they also make like more expensive tubs that will regulate this temperature for you. It's very cold, relatively short period of time. Then there's a sort of hot side of this, which actually is quite a bit more varied. So you can be hot in a sauna or you can be hot in a hot tub or actually in sports, you can be hot in like exercising in like a winter coat. Oh yeah. And like hot yoga, right? I mean, I guess that's a sauna, right? Hot yoga is a sauna, although it's not like a dry sauna.

24:02And in fact, if you get into like the Finns, a lot of the data on saunas from people in Finland and the Finns have like a lot of really specific things about their saunas, like different kinds of saunas, the saunas of the rocks, the saunas without the rocks. I don't know. But at any rate, you are quite hot for a period of time, typically a bit longer. So sauna or hot tub exposure is often something like a half an hour, you know, longer in the hot tub than in the sauna. And the idea is just to raise your body temperature for some extended period of time. So basically, we're talking about being either very cold or very hot.

24:36I think it's just worth saying both of these are uncomfortable. So we're talking about not like a relaxing bath with candles. We're talking about like most people do not enjoy being in a hot tub for 30 minutes, especially since in the heat treatments, usually you have to have your arms in. So you're just really hot. Like it's just like really hot and uncomfortable or really cold and uncomfortable.

25:02Emily Oster:But if I had a nice finished sauna in my office right here and a giant bathtub full of ice, you ask me which one I'd rather spend 15 minutes in, I'm taking the sauna every day of the week. Just going to say it. I think that's right. I hate being both hot and cold. I just, I like to be one intermediate temperature that's perfect. I find both of these ideas like almost unbearable, but I do think I would also choose hot. Although the last time I was in a sauna, I literally made it 45 seconds before I was like, oh my God, I have to leave. I'm going to die. Okay. Oh, you're okay. So you're, you, you really like your, uh, your homeothermia or whatever.

25:42Emily Oster:Yeah, sure. Regular person somewhere, somewhere in the middle, but if there are real health benefits, right? Like maybe it's worth it, which is what I think we need to figure out. All right. Let's, before we figure out the health benefits though, let's talk a little bit about like why these might matter. Like what's the physiology? So you're the doctor. What is the physiology of these kinds of exposures to extreme temperatures. Sure. And let me say like a little bit of philosophy of wellness here, where I think this might be a recurring theme in our podcast, which is that in medical science, we start with this concept called biologic plausibility, which is, is it possible that this thing works?

26:22Emily Oster:Not does it work? Just like, does it make sense? If someone came and said, eating red jelly beans cures cancer, I would say there's no biologically plausible way that that is true. It's not really worth your time. Where I think wellness gets it wrong is that they stop there. They say like, oh, it's plausible, and therefore it does. And where we need to go is like, okay, maybe it's plausible, but like, does it actually? And there's a wider gap between plausible and reality than people often think. So let's first of all, just talk about biologic plausibility. The physiology of cold water plunges is pretty interesting.

26:57Emily Oster:And we have a good amount of data on this, believe it or not, because the military is really interested in what happens to people when they drop into cold water. This is something I guess that we do. We probably do it more often than we know that we do. And so the Department of Defense has funded quite a few studies exploring like the short term and medium term effects of these cold water plunges. It's not exactly the same as, you know, calmly getting into ice water in your backyard. But there's a very standard physiologic response called the cold shock response, which is well described, which happens in the first 30 to 90 seconds of getting submerged in cold water at about 40 degrees, 45 degrees or less.

27:39Emily Oster:And it is essentially involuntary. It is characterized by a deep and rapid intake of breath, like a feeling. Yeah. And that's about three liters of air intake. And just to put it in context, breathing kind of normal, like in and out is, you know, maybe a liter in and out of air intake. So you're really this very deep breath. And this is actually when people fall through the ice or something, this response is what results in a lot of drowning. Because if your head's underwater and you do that, you just suck in a ton of water. It can be very dangerous. You get this dramatic, again, first 30, 90 seconds, a dramatic increase in the sympathetic nervous system.

28:19Emily Oster:This is that fight or flight response, which is going to increase your heart rate, your blood pressure, spike your cortisol levels. It increases adrenaline levels by a factor of about five in these studies. Your adrenaline just goes through the roof in those 60 minutes. Interestingly, dopamine levels increase by two and a half fold. So we often think of dopamine is sort of like a feel good chemical, but you've got a lot of chemistry going on in that first minute in the ice. And it's obviously not entirely pleasant. What was the pleasant part? The dopamine. Oh, the dopamine. The dopamine that's going up.

28:56But is the dopamine going up so your body is convinced, like, don't just die right now. Things could improve the next 90 seconds.

29:05Emily Oster:Yes. We call it hopamine. It's like, I'll give you a hug and then slap be in the face as hard as I can. I don't know. It's not great. I just want to give the good and the bad. Okay. Vasoconstriction. So when you get cold, your superficial blood vessels constrict to reduce heat loss to the environment. So blood gets shunted away from your skin and potentially your muscles. I think we need to get into this a little bit to your central organs, which are the things that really need to keep you alive. So like your heart and your brain and your kidneys, to some extent. It also makes you have to pee.

29:38Emily Oster:And as a kidney doctor, we see this non-frequently in the hospital. So after someone has a traumatic brain injury or a stroke, if we catch them in time and they're in very severe cases, we will induce hypothermia. There is some data there for brain injuries that recovery is better with hypothermia. And we do see that as you reduce their body temperature, the urine output goes up because blood is getting shunted away from the periphery and into the kidneys. So if you jump in that cold plunge pool and you have to get right out to pee, that's a great excuse. One last thing on physiology, because this is something that's actually potentially dangerous with cold plunges, and that is the mammalian diving reflex.

30:18Emily Oster:This is a thing that happens when you submerge your face in cold water. It basically is an evolutionary artifact of our instinct to change our physiology when we're swimming, or especially when we're going deep underwater. What happens in the mammalian diving reflex, again, only if you put your face in the water, is your heart rate goes down. It sort of slows your metabolism. And this is potentially a problem because the cold shock response makes your heart rate go up. The mammalian diving reflex makes your heart rate go down. And there is some evidence that those conflicting signals can precipitate a cardiac arrhythmia.

30:58Emily Oster:And people have died within the first couple minutes of a cold plunge, potentially through this mechanism. So don't put your face in the water. Don't put your face in the water. Like I saw on a lot of the TikToks, it was like, okay, you're in like now go all the way. And like, probably not actually, certainly not in the first couple of minutes while you still have the cold shock response going on. So that is the cold side of things. Okay. It sounds terrible. Tell me about being hot. Okay. The warm side I think is a little bit better. So what happens when you're exposed to heat is that your body does stuff to reduce your body temperature.

31:35Emily Oster:And the thing it does is it dilates blood vessels in your skin so that more blood gets to the skin, the surface area, so you can exchange heat better with your environment. And then you do this amazing thing that humans are very proficient at, which is that you sweat. And so one of the reasons those finished saunas can get to such a higher temperature than the steamy saunas is because you have evaporation of sweat, which is cooling you off. Whereas if you're in steam, your sweat won't evaporate. So people can tolerate the finished saunas quite a bit better because of sweating. You can lose a lot of water through sweat, though, you can put out liters of water in a hot enough sauna.

32:16Emily Oster:You spend enough time there. So dehydration is certainly something to think about. There have been some studies that show that that warmth does release some endorphins, which are sort of, you know, endogenous, feel-good chemicals. So taken all together, it's not as like, oh my God, I'm about to die as a cold plunge, but still might not be pleasant for you, Emily. I don't like it. All right. Okay. So now we know what happens, right? Question is whether it's important, whether it's helpful. Biologic plausibility wise, there's something here. It does something right. It may be increasing your heart rate is good.

32:52Emily Oster:It's like a little exercise, you know, vasodilation, vasoconstriction. You could make arguments that these are good things, but we really need to figure out like, okay, are they good things? And I think where ice has got its most data, Emily, is for athletes, right? Like particularly like athletes who are really doing endurance stuff. Can you tell me about that? Yeah. So I think both ice and heat are things that people who are doing like serious sports try to experiment with. And I think we sort of start with ice. The idea again, to get to the biological plausibility issues, the idea behind ice is sort of similar to like, I have an injury, I have, which partly is inflammation.

33:34You ice your injury. That's like a well-known approach to injury prevention. And I think there's a kind of extension into the sort of cold plunges and icing, which is like, well, maybe if I just iced my whole body, that would like lower my inflammation overall, and it might improve recovery and ideally improve performance. I mean, I think part of what's my guess is we'll talk about this a lot on the podcast, but there's actually a lot more research on a lot of these topics in athletes than there is in other people, in part because it's a very easy population to study because you know what you're trying to achieve, and it's short term, Right.

34:07So you can say, OK, I'm going to put people in this protocol, dump them in the ice after their cycling test every day for three weeks. And then I'll do it not for three weeks and I'll measure their VO2 max on a special bike and blah, blah, blah. And it's like just much easier to think about what you're trying to accomplish and how to measure it. Yeah. And so many of the problems we have studying regular people is what we're trying to say is like, do you live to be 100? And like, I can't measure that three weeks from now, obviously. Exactly. So I will say when we look at ice, my sense of the literature is that it's really not that great, that these cold plunges, maybe they have, you know, a little bit of an impact on sort of subjective muscle soreness.

34:49But in terms of recovery and performance and so on, there just isn't much consistent evidence that these things matter. A lot of the studies have this feature that it's like, well, we did this and we looked at these 47 different outcomes and three of them, it mattered. And it's like, yeah, but that's actually not a very statistically robust result. So for me, the ice for athletes is a bit of a dud.

35:15Emily Oster:Yeah. I, you know, as I was looking into this, I sort of assumed that at least for the real, you know, real athletes, right? Like the professional athletes, because you see these like the football players and the baseball players with the professional trainers and everything like and they have these ice baths in the training house. And I saw enough videos of professional athletes like talking about their process before they get into the ice bath, like what they have to go through mentally and physically. you know, they're like, okay, I've got it because they hate it, right? Like they've got to mentally prepare.

35:49Emily Oster:Like some of them are drinking really hot tea. They're putting on like rubber gloves and boots and things like that so that they don't get like ischemia of their digits and things. And then they, you know, they get in and it has this feeling like, well, it must be really beneficial because they're putting themselves into this. And you're right, you know, looking at the data, I couldn't find much. I found one study that looked at the level of a substance called creatine kinase, which is a muscle enzyme. It goes up when you work out really vigorously because you do damage muscles when you work out hard.

36:25Emily Oster:In fact, that's the way your muscles get bigger is that you sort of damage them and then they come back stronger. And so CK levels go up after exercise. And the people that they randomized to do the ice bath, it didn't peak quite as much, but I'm not sure that means that like, that's even better for you. Right. Like, don't you kind of want some muscle damage? I mean, that's right. Like if you're trying to build muscle, I mean, yes, you do need to damage your muscles to try to build them. But I think the more generally, like, where's the, where's the performance outcome there? You know, this is like, we're measuring all of these things.

36:56And like, we don't really, we don't have a great sense of that. That translates into performance. And I think if you look at the sort of true performance. Stuff being cold is just, we just don't have like a lot of good evidence.

37:07Emily Oster:All right. Professional athletes take note. On the other hand, I will say, I think the evidence on heat in sports is somewhat more compelling. The typical protocol here is hot tub. So basically taking people and after their workout, putting them in a hot tub for 30 minutes. This is literally the opposite of what we just talked about. So I feel like both of these can't work. People don't like this either. And actually, in some of these protocols, they make the hot tubs really hot. Like instead of your your hot tub supposed to top out at like 104 degrees, but they like juke the hot tubs up. So they go up to 107 and then they're like leaving these people.

37:43It was like it sounds horrible, but you do see some performance impacts there. And in particular for people who are going to like race in a hot environment. And now we're in like a really, really niche area. But if you're like training in someplace cold, but you're going to race someplace hot, there's a lot of benefits to heat acclimation, which you can do in a bunch of ways, one of which is the hot tub. So, you know, this is like a I would say there's more evidence for being hot than there is for being cold. But we are still talking about very small. Like if if people are listening to this and they're like, I'm a recreational runner and I have like I'm you know, I'm trying to like run a 5K.

38:24Like you don't need to, the best use of your time is just to exercise and have your regular life, not to get in the hot tub. We're talking about like if you are, you know, a sub elite athlete and you're interested in adding something, I'd add sauna instead of adding cold.

38:41Emily Oster:Let's talk a bit about for us non-athletes. I have to represent my people. You mentioned that the Finns put out a lot of sauna data, some of which is fairly positive when it comes to things like mental health and whatnot, which I always get a little suspicious when all the data on something comes from the country that's really invested in it. It's like if the Dutch put out a lot of positive clog studies or something. So we'll take it with a grain of salt, Finland. But in terms of subjective well-being, it seems like these saunas are good, right? I mean, it's a relaxing thing maybe for some people.

39:20Emily Oster:Yeah. I mean, so I think the most famous paper on this is a paper about Finland, in which they looked at long-term mortality follow-up for men in Finland who spent different amounts of time in the sauna. And, you know, we'll talk a lot about studies like this, but there are limitations to a study where you are using what's called observational data. So people weren't randomized. There may be different features between the people who spend seven days a week in the sauna versus two days a week in the sauna, but they find, you know, pretty in that observational data, there are quite large impacts on cardiovascular mortality.

39:57And it's not inconsistent with some randomized data about sort of cardiovascular improvements and other things like in the heart space as a result of exposure to some of these temperatures. So I think there's like, there's sort of a cardiovascular plausibility there. I mean, I'm curious if that lines, like another way to think about quality of evidence here is to ask whether that effect, which sort of seems to be really a kind of cardiovascular effect as opposed to something else, like it really seems like it's something about the cardiovascular system. Does that line up with what you'd expect based on the physiology of the heat.

40:35Emily Oster:Yeah. Yeah. I mean, it does seem like sauna-ing is sort of a mild cardiovascular stressor. It kicks your heart rate up. It's almost like light exercise in terms of blood pressure changes and heart rate changes. Emily, I see you smiling because, and you're right, it's not as good as actually getting exercise. No, but yeah. But cardiovascularly, there is some of that. This introduces both an opportunity and a problem. The opportunity is, yeah, okay, maybe it is good to get your heart rate up a little bit, however you can. I suspect it's better to get it up by walking around the block a few times than by sitting in a sauna, but it's not nothing there.

41:13Emily Oster:The other thing is something we always worry about in epidemiological studies, which is reverse causation, where people who have some cardiovascular problems might not be able to tolerate the sauna as much. And so then when you kind of follow people over time, you're like, oh, people who do more sauna live longer when in fact it's people who are less healthy do less sauna to begin with, which sort of complicates the issue. But I don't think it's inconceivable that either the cardiovascular benefits or I'm a big believer in the power of like doing something intentionally for yourself. And there's a lot of stuff in this space where I think it's that it's like, OK, this is me time.

41:51Emily Oster:Right. Like I'm getting in the sauna. I'm not bringing my phone. I'm just sitting alone with my thoughts. And maybe you don't even need the heat. Maybe it's just a quasi-meditative state that I think actually might be beneficial for mental health. Do you think the same about the cold plunges? No, not at all. No, because I think in the cold plunge, I think instead of like quietly being with your thoughts, your brain is like, what are you doing? Please leave this horrible place. You're about to die. I'm shutting down your body systems as we speak. Yeah, that's what I think. So one of the things people will sometimes talk about is the idea that saunas are a detox, that you're sweating out the toxins, a lot of efforts to get rid of toxins.

42:34So do you think that if you sweat more, you get more of your toxins out? And what are the toxins specifically?

42:39Emily Oster:No, no, no. No, not a chance at all. You have two organ systems that are designed to detoxify you, the liver and the kidneys. That is their entire evolutionary purpose. They do an amazing job. Sweat is 99 % water. The other 1 % is salt and sodium chloride. That's what sweat is. So you will lose water. You will lose salt. Both of these are things that nominally you need to survive. And so we would want to replenish those after a sauna. Just to put some numbers in it, there was a study that looked at the excretion of organic pollutants in sweat. So if we're worried about toxins. Here's a good one for you, right?

43:20Emily Oster:It's the stuff that like we spray on crops and things like that. It's in our system. It gets in our blood. You can measure these things. And so took some people, put them in the sauna, tested their sweat. And they determined that if you were to leave people in the sauna for an entire day, and somehow they survived. So, you know, getting a ton of sweat out of these people, you would excrete through the sweat 0.01 % of the daily accumulation of organic toxins. So there is a measurable and tiny amount, but it is spitting in the hurricane of potential toxins that are out there to try to excretify sweat.

44:00Emily Oster:That's not what sweat is designed for. That's what urine is designed for. That's what bile is designed for. You have organs that do this. Sweat is designed to cool you off. It is extraordinarily good at this. If humans are these amazing animals that evolved on the African plains to do persistence hunts against animals that can't sweat as efficiently as we can and we maintain our cool under the African sun and they collapse of heat stroke and then we kill them, like that is where we come from. That is what sweats for, not to get your toxins out. Sorry. Okay, but I think what people have noticed is a good story about the gazelles.

44:37But I think what people have noticed is like if you drink a lot at night and then you go into a sauna the next day, you smell like vodka. And that I think people perceive that to be like, you know, cleansing them from toxins. So is that why is that? Alcohol is special. Alcohol is special. I totally agree. Say more.

45:00Emily Oster:Alcohol and water do not know that they are different chemicals from one another. So virtually throughout the body, alcohol and water are freely exchanged in the solution of your body. So whatever your blood alcohol content is, is your sweat alcohol content. They just, they go together like that. Now, it's not much, but it is enough to potentially be detectable. Again, it is not enough to clear alcohol from your system by any stretch. You have an organ that is designed to do this. It's called your liver. Your liver can clear for an average man, and it varies, but about a drink's worth of alcohol per hour from your bloodstream.

45:45Emily Oster:Don't try this. It gets worse the more drinks you have. Sweating in a sauna, we're talking less than a hundredth of that amount. It's just not the way to get alcohol out. It's not the hangover cure that one hoped for. No, it's definitely not. In fact, the dehydration that comes from Asana is probably going to make things worse. Also make things worse. The last thing I wanted to say on the benefits is I came across what I think was an extremely interesting study about women with obesity and PCOS where they did – it's a relatively small study. to be, they did actually a pretty short intervention where they sort of put them in the hot tub for an hour a week for eight to 10 weeks.

46:31And there actually were a bunch of improvements in blood pressure and other like cholesterol metrics. So no improvements in weight, but just things that looked like, as you said at the beginning, like a little bit like they had exercised, like similar to if you had put people in exercise. So, you know, I think part of what was interesting about that for me was, you know, I, I think exercise is great, but exercise is not always feasible for everybody and is not something everybody wants to do. And so to the extent that there's a, this is sort of something that could be helpful in some cases, maybe on the way to exercise, or maybe in addition to, um, if it feels like there's, there's sort of something there that might be meaningful enough that it's worth considering for some people.

47:16I buy it. Okay. But not all people. So what, when we sort of talk about, are there people who should not do this? Pregnant.

47:26Emily Oster:Yeah. Yeah. There's always people who should not do everything. You know, again, if you're curious, if you're one of these people, of course, talk to your doctor. But broadly speaking, both of these, hot and cold, are mild cardiovascular stressors. So people with preexisting heart disease who are at risk of heart disease, you know, certainly can be put at mild risk by going into either of these situations. People at risk of arrhythmias, particularly with the cold plunge, and I'll just say it again, I would not put your face in the water when you're in the cold plunge. The problem with arrhythmias is that a lot of people who are at risk of them don't know that they're at risk of them, at least the first time it happens.

48:03Emily Oster:And so it does make me a little bit nervous. Obviously, jumping into a cold body of water as opposed to like a tub in your backyard has extra dangers because of that cold shock response. You know, people jumping into cold lakes can just like go under and not come up and it's very hard to find them. Deaths have been described. So, you know, this is something to take seriously and carefully. I will also mention that there have been some studies if you're a man that is interested in fertility, at least in the short term, that prolonged exposure to heat does kill sperm. And so if you and your partner are trying to get pregnant, it's probably not the best time to do significant sauna or hot tubbing.

48:50Emily Oster:And women who are pregnant, that elevated body temperature can certainly be damaging to the fetus. And so we don't recommend hot, certainly for pregnant women. And I probably wouldn't recommend cold in that case either. Just disagree. Actually, I spent a bunch of time at some point looking at the cold plunge data in pregnancy. And I would say, although, you know, of course the data is limited because cold plunging seems terrible. And why would you do it ever? There actually are. There is some evidence on this. There's actually no real reason to think that, you know, particularly if you are a person who generally does this, that you would need to stop doing it when you were pregnant.

49:32which is not the case of hot tubs and saunas where the risk for neural tube defects, particularly for exposure in the first trimester means that that's a no, no.

49:41Emily Oster:Fair enough. Fair enough. All right. No saunas, maybe cold plunges, but be careful. So my last like risk question that I have always wondered about is like, can you get frostbite from being in the, like if I get in and I have some exposed parts, fingers toes for men i mean aren't you worried your penis is going to get frozen off honestly isn't that a thing i'm would be worried well i i hadn't thought about it until just now well now i'm worried it's not it's not my go-to every time geez um so typically in frostbite we imagine that it occurs when the external temperature is below freezing because you have ice crystal formation So that being said, you can get ischemic digits.

50:32Emily Oster:So that response to cold is that the blood vessels in your superficial blood vessels constrict, and it can be quite powerful. Particularly, there's a phenomenon called Renaud's phenomenon. Many women have experienced this. It's horrible. And I mean, men have it too. It's just more common in women where you have such severe vasoconstriction in your finger, typically fingers, but it can happen in toes too, that it's just white. There's just no blood flow there. That can be triggered by cold plunges. And so many people who do this routinely actually wear like some rubber gloves and rubber booties and even rubber boxer shorts to get to the issue that you are referring to, Emily, to try to make sure that those nibbly bits, as we call them in the medical profession, don't get exposed to too much of that cold.

51:24Emily Oster:Um, broadly speaking, I think if you're healthy and you don't have vascular problems to begin with, even some vasoconstriction from the cold plunge that, you know, is painful and hurts is not going to result in the loss of a digit the way you could if you're, you know, outside in sub-zero temperatures. So you won't lose your fingers, but your nibbly bits could be uncomfortable. Thank you. Yes. I'm sorry to use medical jargon. Right. No, it's fine. I think we're going to be using that in the future. Um, okay. So Perry, what is your one thing takeaway on cold plunges and saunas for the listener?

52:03Emily Oster:Cold plunges seems like modern day self-flagellation. Be kind to yourself. I don't think it's worth it. Saunas, sure, go for it primarily because it's a nice time to have some time to yourself and relax, which we all need more of. My one thing is similar. What I would say is if hot tub sauna on a regular basis sounds like something that would serve you emotionally or in some other way, then that seems lovely. And in fact, if getting in this ice tub in your backyard would serve the same things, and that's a nice date, that also seems fine up to the concerns. But for most people, I don't think I would invest in either of these for significant health benefits.

52:49There are a lot of other things I would put on the list for people first.

52:53Emily Oster:Sounds good. We will be back right after this with your questions.

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53:55now. As a woman in the industry, you're always underestimated. So you have to work extra hard and you have to push the narrative in a way that doesn't compromise who you are and your integrity. You know, I like to say I was kind of like a silent ninja. Each week, I have unfiltered conversations with female founders, creatives, and leaders to talk about ambition, visibility, and what it really takes to build something meaningful in the public eye. Because being a Nick Girl isn't about the spotlight, it's about owning it. I think the negatives need to be discussed and they need to be told to people who maybe don't do this every day just so they know what's really going on i feel like pulling the curtain back is important listen to it girl with bailey taylor on the iheart radio app apple podcasts or wherever you get your podcasts good people what's up what's up it's quest love so recently i had the incredible opportunity to have a real conversation with uh actress and producer jamie lee curtis ahead of the release of her new thriller series, Scarpetta.

54:53I can honestly say I've never done an interview like that before. You know, at one point I shut my laptop down and we just started chatting as old friends, recent Oscar recipient. So we have some commonality there. I predicted that, by the way.

55:09Emily Oster:And you said these words to me, dust off your mantle. Yes. And I looked at you and I said, what? and you said, dust off your mantle. And then I left and that was it. And then when all of that happened, I remember the next morning, I think I wanted to like write you and go, how did you know? Listen to the Questlove show on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. What if mind control is real? If you could control the behavior of anybody around you, what kind of life would you have? Can you hypnotically persuade someone to buy a car? When you look at your car, you're going to become overwhelmed with such good feelings.

55:53Can you hypnotize someone into sleeping with you?

55:56Emily Oster:I gave her some suggestions to be sexually aroused. Can you get someone to join your cult? NLP was used on me to access my subconscious. NLP, aka Neuro Linguistic Programming, is a blend of hypnosis, linguistics, and psychology. Fans say it's like finally getting a user manual for your brain. It's about engineering consciousness. Mind Games is the story of NLP. It's crazy cast of disciples and the fake doctor who invented it at a New Age commune and sold it to guys in suits. He stood trial for murder and got acquitted. The biggest mind game of all? NLP might actually work. This is wild. Listen to Mind Games on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

56:45Emily Oster:And we're back with our listener question of the week. Hi, Emily and Perry. This is Ellie from Toronto, Ontario. So I'm a parent in my late 40s, and I've been running on about, I don't know, five or six hours of sleep a night for, well, many, many years. So my question is, I function, you know, I mean, I get through my day, I've convinced myself that I've totally adapted to that amount of sleep, and it's fine. But I keep hearing that chronically not getting enough sleep can kind of damage your health quietly. And so I'm wondering, is regularly getting this amount of sleep harmful if you feel fine?

57:32Like what does the research say about long-term effects on things like my metabolism or my heart or my mood, my weight, et cetera? And then I guess the last piece is if someone can't realistically get eight hours, what are the most meaningful ways to reduce the damage? Thank you.

57:54Emily Oster:Emily, I'm so excited about this question because I get to talk about familial natural short sleep, one of my favorite and most awesome genetic conditions. So there are people out there literally who do not need to sleep as much as other people. Approximately 1 % of the population have this genetic condition called familial natural short sleep. I will point out that it's not a syndrome or a disease because it doesn't cause any problems. In fact, it seems to be quite beneficial. These people need to sleep about four to six hours a night. They suffer no ill effects. They might even be protected against Alzheimer's disease.

58:34Emily Oster:There's some suggestion there. It is inherited through families. But the fact is, unfortunately, that most of us aren't lucky enough to have the special genetic mutation that prevents dementia and makes you not have to sleep at night. How would I know? So before we get into regular people, how would I know if I had this mutation? You might know because you sleep four to five hours a night and feel completely fine, or at least you might suspect. And then many of the genes are actually known. So if you were genotyped, they could detect that you had this variation. That is fascinating. However, most of us do not have this variation.

59:08And most of us need more than this amount of sleep that this person is getting. I mean, so first of all, I just think we underestimate how important sleep is. I think most adults, especially adults who have jobs and kids and et cetera, kind of think of sleep like a sort of nice to have, you know, sort of like a pedicure, right? Like, you know, it'd be great if I could get one, my feet would look better, but like, if I can't get one, it's totally fine. And I sort of think people should think of sleep much more like a biological necessity. Like, and if you don't get enough sleep, it's like torture.

59:42I mean, sleep deprivation is a form of torture. And we know that people's working memory and executive function is affected by even relatively limited limitations on amount of sleep. So they have studies where they'll take away, you know, a couple hours a night for some period of time. And over a few days of that, you actually end up with a level of functioning that's not dissimilar to if you literally skip the night of sleep. And it's especially hard on working memory, which is something that when you think I need to do something and then you go into the other room and you've forgotten what it is, that's your working memory.

1:00:16And that's not good if you are not sleeping enough.

1:00:19Emily Oster:Yeah, I couldn't agree more. It's super important. Most people need about six and a half to eight and a half hours a night. People do vary a little bit around there, but you really got to get it in there. You've got to prioritize it the same as you think about like getting some exercise or eating well or whatever. It is a critical thing to focus on. So do your best. I will also say, you know, I want to recognize that it is really hard to get enough sleep and that for a lot of people listening to this, you probably have multiple jobs and multiple children. And so this is partly, you know, giving yourself a break and saying like, hey, if I'm not in bed, you know, at 10 o 'clock fully asleep and up at, you know, six, like Brian Johnson, like it's okay.

1:00:56Like you're, you're not going to immediately die, but it's also saying, you know, this should be something you prioritize. And so thinking about, you know, what is feasible for me to improve my sleep? I think that's something that we should care about. And I think at some point we should do a whole episode on the science of sleep because I love the science of sleep. Every animal sleeps. It's so interesting. Dolphins sleep half their brains at a time while they're swimming. So whatever. I'm going to pull out so many great facts for you. So, Perry, do you have any quick tips for better sleep if someone wants more sleep?

1:01:27Emily Oster:The standard sleep hygiene stuff here, which is you don't want to drink caffeinated beverages typically after like 4 p.m. You might not even want to drink any beverages as you approach 8 o 'clock, 9 o 'clock at night, just so you don't have to wake up in the middle of the night to pee. We want people sleeping in dark, quiet rooms as much as possible. Those noise machines and stuff can actually disturb sleep a little bit. If you are in a loud environment, earplugs are awesome if they're comfortable for you. And the bed is a place to sleep and have sex, not to eat and watch TV and be on your phone and whatnot.

1:02:01Emily Oster:I'm okay with reading in bed, but I would read an actual book as opposed to a phone because that blue light that comes from the screen can actually keep you up a little bit. That's it. Join us next week when we ask, what's the deal with the blockbuster weight loss drugs, GLP One's? Wellness Actually is produced in association with iHeart Media. Our senior producer is Tamar Abishai. Our executive producer at iHeart is Jennifer Bassett. Our theme music is by Eric Deutsch, and our content is for educational purposes only. If you like the show, help other people find us. Leave a rating and review on Apple Podcasts or your podcatcher of choice.

1:02:42Emily Oster:And help us spread the word about the show. Don't give the TikTokers all the power. And don't forget, we want to hear from you. Head over to wellnessactually.fm and leave us a question for our mailbag or suggest a topic for a future show. We'll let the influencers have the last word. All right, guys, so I am three weeks into cold plunging, and I'm going to explain to you guys the differences I'm noticing and whether I think this is worth it or not for you guys to go out and get a cold plunge for yourself or build one. But I've been doing it for three weeks now every single morning, and I will tell you the very first thing is that I highly underestimated how much I was not going to want to get into that cold plunge every day.

1:03:31Emily Oster:Here's the truth. You could literally be adored by everyone and then come home and still get completely ignored by your own cat. It's classic cat behavior. But new Shiba Premium Puree is a lickable treat that changes all that. They're protein-rich, made with bone broth, and have the smooth, creamy texture cats go crazy for, especially when it's hand-fed. Yeah, it's more than a treat. It's a fast pass to favorite human status. So feed your cat Shiba. and go from totally ignored to truly adored in just 12 days, guaranteed, or your money back. Learn more at Shiba.com. Wait, this is a soda? Yeah. And it has protein?

1:04:0910 grams. No sugar? Zero. And it actually tastes good? It's Sky Pop. Sky Pop Protein Soda delivers the refreshing taste you want from a real soda. Crisp and delicious with 10 grams of complete protein, zero sugar, and just 45 calories. so you're not choosing between great taste and real benefits. You're getting both in every sip. Skypot Protein Soda. Reach for the sky. Get your Skypot Protein Soda now at Target. I'm Bailey Taylor, and this is It Girl. This podcast is all about going deeper with the women shaping culture right now. Yes, we will talk about the style and the success, but we are also talking about the pressure, the expectations, and the real work behind it all.

1:04:49As a woman in the industry, you're always underestimated, So you have to work extra hard in a way that doesn't compromise who you are and your integrity. You know, I like to say I was kind of like a silent ninja. Listen to It Girl with Bailey Taylor on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Peace to the planet. Charlamagne Tha God here. And listen, we are back. The Black Effect Podcast Festival is back in Atlanta on April 25th at Pullman Yard. Yeah. And the full lineup is nuts. We got the Grits and Eggs podcast, Deontay Kyle and Big Ice Cup Cat. We got Club 520 with Jeff Teague and the gang.

1:05:26Don't call me white, girl. Mona will be there. Keep it positive, sweetie, with Crystal Renee. We got Reality with the King with Carlos King. And yes, Drink Champs will be in the building. Plus, you know, we're going to have a lot of guests. So you need to join us. And we got the Black Effect Marketplace, the picture podcast, and everything you expect from the Black Effect Podcast Festival. Tickets are on sale right now. Go get yours at blackeffect.com slash podcast festival. Don't play yourself, okay? Pull up.