Cold Exposure for Mental Health

Can cold exposure improve your mental health? In this episode, we explore the science behind cold therapy methods like ice baths, cryotherapy, cold-water swimming, and cold showers. Backed by research, we dive into the physiological and psychological effects of cold exposure, including its impact on mood, anxiety, dopamine, norepinephrine, and stress resilience. We discuss historical practices, benefits for mental and physical health, and common misconceptions around claims like immune boosting and inflammation reduction. Learn practical tips, safety precautions, and how cold immersion could fit into your mental health or wellness routine. Whether you're curious about the Wim Hof Method, the dopamine-boosting effects of cold plunges, or the latest studies on cold exposure's antidepressant potential, this episode offers insights you won't want to miss. By listening to this episode, you can earn 1.5 Psychiatry CME Credits. https://www.psychiatrypodcast.com/cme-program Link to blog. https://www.psychiatrypodcast.com/psychiatry-psychotherapy-podcast/episode-232-cold-exposure-for-mental-health-benefits Link to YouTube video. https://youtu.be/Xnvy6MA4jGY

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:13David Puder?

  All right. Welcome back to the podcast. I am joined today with Liam Browning. He is a return guest to the podcast because of his deep desire to be willing to dive into topics of my, I guess, our interest, my interest. This one was more my interest. Today, we'll be talking about cold exposure. It's a practice of immersion into ice baths, cold plunges, cold water swimming, cold showers, cryotherapy, which has surged in popularity. I remember I watched the Wim Hof documentary and you watched these guys visiting Wim Hof.

• 0:55David Puder?

  And I had never been in a cold immersion when I watched this thing. And you know, you're watching these guys jump into ice cold waterfalls. And you're like, I don't know if I could do that. You know, they go on this like, super long hike in the Arctic cold freezing. And they're in the sauna and they're in their back in the cold. And then they're in the sauna and they're back in the cold. And you're like, what is this? Like, and then, you know, all of a sudden, everyone starts talking about it. You know, so I got interested in it a couple of years ago, built my own cold plunge, went out this morning, did four minutes at 42 degrees Fahrenheit, just because I knew I was coming on, you know?

• 1:36Speaker 01

  Yeah. You had to say that you've done it. So you can talk about it.

• 1:39David Puder?

  I had to re-experience it. And, and you know, I've, I've recommended it to a couple of patients who have had good results. We're going to talk about this today. We're going to go through every study. This will be the most comprehensive audio article out there, I would say, at this point. And we've, we've looked at other podcasters, famous ones that have talked about this, but we will go study by study. What is currently known? What is not known?

• 2:10David Puder?

  We were even talking yesterday, me and Liam, about like, man, we should, we should raise some money to study this and do a really nice randomized control trial. Cause there's, there is really nothing.

• 2:20Speaker 01

  No, nothing at all, really.

• 2:22David Puder?

  There is, there is no really nice randomized control trials that we can find. Like, and we'll talk about all of them. And, you know, it's kind of like, uh, kind of like the ketogenic diet for some people. It's like, they swear by it. Not very many of my patients will do it. Right?

• 2:42David Puder?

  You know, it's kind of like off-label. It's got its own risks. We're going to talk about those as well. But, you know, on this podcast, we really seek to look at

• 2:55David Puder?

  things that may work. You know, there's a lot of things we don't cover, like bee stings. Probably not going to work. Homeopathic remedies, not going to work. Right? It's just diluted water. Sorry if I offended you. I can give you some empathy if you come to me for therapy. Uh, okay. So Liam, back at it, recently engaged.

• 3:19Speaker 01

  Yep, thank you.

• 3:21David Puder?

  So excited to see those pictures.

• 3:23Speaker 01

  Yeah, I'm so excited. Yeah, you'll, you'll be at the wedding too. So don't worry.

• 3:27David Puder?

  Yeah, Liam told me I'm going to officiate the wedding. Yeah, we're going to, we're going to live stream it on Instagram. That's, that's a joke. No, I'm just happy to be there and celebrate you. And celebrate, man, there's so many of my patients that want to be happily engaged, happily married. And it is a tough dating landscape right now.

• 3:48Speaker 01

  Yeah, it's really tough out there. And I, I feel for them. A lot of my friends are, are going through it. So, yeah, it's really tough. I just want to say, yeah, thanks for having me back on. It's always a pleasure to dive into these, some of these topics together and really follow our curiosity about. You know what's been going on in the mental health sphere? Because this is really a practice that's talked about by so many different podcasters, so many different social media influencers. And you know, they're making all these, these claims about how it's beneficial for their mental health, like helping them boost their mental clarity and all these different claims. So I just really wanted to dive into this with you and it's been an enjoyable experience so far.

• 4:30David Puder?

  Some say the best thing about cold plunging is telling other people that you're cold plunging.

• 4:35Speaker 01

  Yeah, exactly. You get to put it on your Instagram story and your Snapchat.

• 4:40David Puder?

  It's like, look at what I did.

• 4:42Speaker 01

  Look what I did. I woke up at 4 a.m., did my cold plunge and did it run while you're still in your warm bed. That's like the ethos behind it, I feel.

• 4:50David Puder?

  Liam, Liam came out to my house and he got to cold plunge at my house. And it was like, it was, it was one of your first ones, right?

• 4:57Speaker 01

  Yeah, that was my first time.

• 4:58David Puder?

  That was your first time. Okay. And what was that experience like?

• 5:02Speaker 01

  Oh, it was, it was an immediate shock. Like I've done cold showers before, but I, I don't think anything compares to getting into water that is like ice cold. Like you immediately just want to get out. Like it's so cold. And I think yours is especially cold too. He's like, you've got the whole setup. So the water's constantly circulating too.

• 5:22David Puder?

  The water is circulating. That really takes, um, cause normally when you're in cold water, you, you develop a little bit of a, um, a barrier eventually. That's why like the first 45 seconds are the hardest, but if you have it constantly circulating, the areas that are circulating are so cold. I think you did a full five minutes.

• 5:43Speaker 01

  Yeah, I did five minutes. It was pretty intense. Like I, I probably did it a little bit more than I should have because it was my first time, but I wanted to get the true effect. And yeah, it definitely was a shock at first, but you kind of ease into it and I, I ended up being really calm and relaxed after. So I can definitely see like why people would think that it's beneficial.

• 6:03David Puder?

  There's some days I come home and I'm like, it's the haze of war. You know, I've talked to patients about trauma, you know, hours of different therapy sessions, you know, I usually do about eight and a half hours a day on a full day. And my wife will be like, can you go cold plunge? Like, because afterwards, my brain just comes back online, you know, it's like, it just wakes up.

• 6:26Speaker 01

  Right, really, really, like, it's a shock to the system.

• 6:30David Puder?

  Yeah, so let's talk about the different forms real quick. Cold water immersion, usually around forty to sixty degrees Fahrenheit, that's five to fifteen degrees centigrade for two to fifteen minutes. I would say fifteen minutes. You cannot do fifteen minutes comfortably at forty degrees. Like, when you're around forty degrees, just from my experience, five minutes, seven minutes, you're good. The really dark studies from Nazi Germany, they would, they were trying to, they would stick people in the ice cold water, see how long they could live. Forty-five minutes for a lot of people around that time. So, you know, fifteen minutes is pretty, pretty extensive.

• 7:08Speaker 01

  Yeah, I think that's for some of the more warmer temperatures, because we'll get into some of these studies, but one of them, it was like sixty degrees Fahrenheit, and they were in there for an hour. So I mean, it's like, almost the temperature of a colder pool.

• 7:21David Puder?

  It's like, it's like we also, when you visited, went to a spring, it was like, it's like sixty-five, sixty-six degrees all year, which is why in Florida, it's like a total amazing place to go, right?

• 7:36Speaker 01

  Yeah.

• 7:36David Puder?

  But yeah, you'll be in there for an hour and you won't think about it that much. But I, and that's why I'm like, reading these studies, and I'm like, oh, can you guys go a little bit colder for even that, for that five-minute, six-minute time period? Because that seems to be like that sweet spot for me. There's cryotherapy, which is two to four minutes at 166 to 220 degrees minus, negative Fahrenheit. Now, you know, we can't even think in terms of how cold that is, like in terms of our normal understanding, but you have to realize the conductivity is totally different than water.

• 8:17David Puder?

  And I've had friends who have done cold plunging with me and done cryo, and they say that the cold plunge is a lot harder psychologically. Cryo, you know, 25 times more, basically, conductivity with water compared to air. Okay. And I think when you have circulating water, it's probably, it's probably even worse because you don't have that like thermal barrier that develops. So, yeah, so there's cryotherapy, but we have some studies on that we're going to talk about because there actually have been some. Talk about cold showers. So some patients will be like, can I just take a cold shower? And I'm like, you're in Florida, then nothing is cold here. It's like the water comes out at 75 degrees. That's not cold.

• 8:59David Puder?

  You need to go to, there's a, there's a place around here. It's like a, some Y MCAs, there's some different gyms that have cold plunge saunas. I'm like, you just go to one of those and try it out, see if it's helpful. And then there's ice baths, just putting ice into your, like, put, you know, put the water as cold as you can, add some ice. I did this, this is how I started, did this with my kids. Started out with like 30 pounds of ice, worked our way up to about 50, 60.

• 9:28Speaker 01

  Wow.

• 9:29David Puder?

  And then we'd have some friends over and do it together and kind of a fun experience.

• 9:33Speaker 01

  Was like the whole bath ice?

• 9:35David Puder?

  No.

• 9:35Speaker 01

  Or is it? With water too?

• 9:37David Puder?

  Yeah, with water, mostly water. 50 pounds is not that much, actually.

• 9:41Speaker 01

  Yeah, because a lot, a lot of athletes, they use the ice baths, like an entire tub of just ice. And that's like, it's not as cold because there's some pockets of air in the ice.

• 9:52David Puder?

  Yeah, I think Wim Hof has been in pure ice. For like, what?

• 9:58Speaker 01

  I think it was like a couple.

• 9:58David Puder?

  Twelve hours or something?

• 10:00Speaker 01

  Yeah, it was hours.

• 10:01David Puder?

  Yeah, and so it's it's a lot easier because essentially there's very few points of contact with your skin, especially if you're using the right type of ice. And then essentially, you're just in cold air and then the water drips down.

• 10:15Speaker 01

  Yeah, so impressive nonetheless, 12 hours is insane.

• 10:19David Puder?

  It's impressive. Yeah, it's not like the Guinness Book of Records is not fun in my mind for heat or cold.

• 10:28Speaker 01

  No, we talked about the heat one where they're in a boiling hot sauna and, you know, it's just crazy how much the body can withstand after it adapts to stuff.

• 10:37David Puder?

  They stopped, they stopped doing it so hot after some people passed away, unfortunately. But they were doing like six or seven minutes at like 230 with steam. It's wild. And then, um, you know, there's a video I saw of the Iceman, Wim Hof, swimming under ice water for like 50 yards. It's like, oh, my gosh, because I put my head underwater for like 10 or 15 seconds and I start getting that like freeze pain, you know?

• 11:09David Puder?

  So I can't imagine.

• 11:11Speaker 01

  Now he's a beast.

• 11:13David Puder?

  Okay, so the history of cold therapy. Do you want to talk about this at all?

• 11:17Speaker 01

  Yeah, so this is a practice that kind of goes back, at least what I was able to find to like Greek and Roman times, where we talked about before, they had these these hot bath houses. And they also had some cold water in these houses too with ice, apparently. And, um, you know, this is also something that Hippocrates and Galen, like these physicians back in those times, they espoused the the benefits of cold water for the use of fever. And Galen, the Roman physician, he actually started using ice for to stop bleeding. So even then, they could observe that there was some vasoconstrictive effects of of cold.

• 11:57Speaker 01

  And, you know, this practice is, it's kind of gone out of favor with more Western cultures like in the Americas, but it's been continued through the Nordic countries like Denmark, Finland and so on. And where there it's used as. Kind of like we talked about the hot and cold therapy, where they go from a sauna into the cold plunge and then back into sauna. Or it's often used as like a way to fertilize yourself after work. Like in Denmark, there is a pretty big culture around ice water swimming where they go out into the sea after work. And they all meet up and then they go plunge into the water, swim around for a couple of minutes.

• 12:40Speaker 01

  And then they hop back in and they continue on with their day. So it's really a practice that's ingrained into the culture. And it's starting to get picked up now by like these podcasters and social media influencers. So a lot of people in America are starting to do it.

• 12:54David Puder?

  Yeah, and I, you know, we looked at this, this study, the Kupio ischemic heart disease study, which was discussed on episode 221 on sauna, basically. And there was a cohort of Finnish men that they followed for decades. And they found that those that used sauna, is the sauna, four to seven times per week, had huge reductions in significant medical issues. You know, 62% lower risk of stroke,

• 13:35David Puder?

  66% decreased risk of dementia, 37% lower risk of pneumonia, 78% lower risk of psychotic disorder. Okay, there was a decrease in all-cause mortality compared to the people that were using the sauna one time a week. Interestingly, in Finland, there is no zero time per week control in the cohort, because everyone uses the sauna roughly one time a week. So I was thinking about this and I was like, well, how often are these people using cold exposure as part of their thing? Because a lot of the times they'll talk about like how they do hot, cold, hot, cold, cold, hot, cold, hot, you know, usually they finish in cold.

• 14:18David Puder?

  So I emailed the authors, we haven't heard back. But we did, we did a search and it's pretty usual to end with either a cold shower, a cold dip in a lake. And so one of the things that wasn't Controlled in this study was the the the use of cold and how that impacts the overall physical, mental well being as well.

• 14:46Speaker 01

  Right, and there's really no epidemiological studies looking at this practice, which I think that's somewhere that we could start with pretty easily for looking at the the mental health benefits of cold. And I think, yeah, we'd have to look at some of these Finnish cultures who use a practice more regularly compared to like in the US where not as many people use it. So yeah, I mean, it's definitely a practice that's more common there. So there could be some benefit to it that was that you can attribute some of the benefits of sauna potentially from this study.

• 15:18David Puder?

  There's a big, large winter swimming society out there, you know, 100,000 members type of thing. So this is, this is something that in the US is just completely unknown. So it's like, we're discovering it. No, we invented it in the US. It's kind of how we feel, don't we? They didn't, they didn't discover this. We are the ones that are discovering the sauna, the cold plunge. The thing is, is that, you know, in Florida here, there's no cold water. Like, you have to create your own. So I like, bought this large cooler and I hooked up, I spent several weeks kind of designing this thing, built a pump with a filter and then it goes through like a refrigerating device and back to

• 16:02David Puder?

  the thing. Otherwise, you have to spend like five, six grand on it, which is so expensive.

• 16:07Speaker 01

  Right. If you don't have access to like a cold lake, then you're not, you don't have like an easy way to do it. Whereas like in these Scandinavian countries, everyone is outside, like they have easy access to a lake. And like them, I think that one of the main differences between cold plunges here versus there is that there is more of like a social practice. Like, they use it all to relax together, or they do it like after work, like I mentioned in Denmark. Whereas here, it's more so like individuals, like I do the cold shower by myself, then I get on with my day, or like I do the cold plunge. So I think there's less availability for that, the social aspect, at least in the States.

• 16:46David Puder?

  Yeah, and I built a sauna. And so next time you come out here, you're gonna have that group aspect. I don't know, I think there's something about that that's fun. You know, it's like four people come over, cook in a sauna together, go to a cold plunge. I'm like, okay, follow the data, right? Okay. So what is happening to the body during cold exposure? So there's the bottom up signals, and then there's top down signals. Talk to me first about the bottom up signals of the body, you know, of getting in.

• 17:20Speaker 01

  The bottom up signals are like the signals from the body essentially telling us that we're in shock, like we need to do something to get out of this situation or scenario. So that first starts with the thermoreceptors in the skin detecting the rapid temperature drop. And then this eventually leads to activation of sensory fibers in the spine and then up into the hypothalamus that detects the temperature change. And you know, this rapid temperature change, again, tells us that we're, we need to move and to get out of this situation. So this activates the sympathetic nervous system. Adrenaline is involved here, norepinephrine or noradrenaline, they're released from the adrenals in response to

• 18:02Speaker 01

  the signals from the hypothalamus and the sympathetic nervous system. And at the same time, we also get activation of the HPA axis. And then this also continues the release of norepinephrine in the brain, too. So in the brain, these are the top down signals, even before we start doing the cold plunge, in anticipation of the cold, like we see the cold plunge in front of us and we kind of have to hype ourselves up to get into it. So that's like already activating parts of the brain telling us this is a scenario that's going to be dangerous to us. So these parts of the brain, like the prefrontal cortex, the insula, the amygdala, they're processing the relative danger it is to us. And all

• 18:44Speaker 01

  these circuits, they converge onto the anxiety centers of the brain, the salient centers. And these will then go on to activate the hypothalamus once again, and to increase the release of corticotropin, a releasing hormone, which is the first hormone of the HPA axis, and is also a neuromodulator, increases activity of the amygdala. And then also, the part of the hypothalamus that releases CRH will then activate the locus cerullius, which is the brain's main storage center for the norepinephrine. So in effect, even just from looking at the cold and anticipating it, you have a psychological response that activates sympathetic nervous system as well and the HP axis.

• 19:26David Puder?

  Yeah, and it's interesting how, when this happens, you know, that amygdala response, the locus cerullius releasing the norepinephrine, that fear response, I mean, you gasp. Like, there's a gasp reflex where you're just, "Oh!" And actually, that gasping is what usually leads to people breathing in the cold water. Like, when people break through ice and they hit cold water, and that gasp reflex is so strong. Other things that can happen, the vasoconstriction, blood vessels, right, on the skin contract so that you're not, like, releasing a ton of temperature out.

• 20:11David Puder?

  Nerve conduction slows in the cold, leading to a reduction in pain and sensation eventually. The heart rate typically increases if there's a lot of fear, but I would say from experience, it actually drops for me quite a bit. So if I'm coming in from a workout, my heartbeat could be around, like, 95. I get in, it drops 20 to 30 beats almost immediately. There can be a little bit of an increase in blood pressure. There can be this rapid shallow breathing, which I think is why the Wim Hof breathing is this kind of like, you know, they'll start fast and a lot of breathing, and then they'll hold their breath when they get in. There's different ways of doing it.

• 20:56David Puder?

  But essentially, this is a great time to do slow and, like, long breaths to practice that. And that is a way, like, sometimes I'll just count my breaths, the first 20 are the most painful. And just slow, long breaths. And everything in you doesn't want to do that, but that helps you regulate the stress response. Yeah, so, interestingly, norepinephrine increases two to threefold and remains elevated for hours. And we're going to talk more about this, but I think that may be part of the the health, the mental health benefit, right?

• 21:34Speaker 01

  Right.

• 21:34David Puder?

  We think about like medications that increase the norepinephrine often have to do with focus, concentration, sometimes for depression as well, serotonin, norepinephrine reuptake inhibitors, right? There's the norepinephrine reuptake increase. Now, there is a slight difference. We're measuring, we're measuring blood levels of norepinephrine, measuring peripheral.

• 21:57Speaker 01

  Right. With their, with their patients, yeah, we're not measuring the epinephrine in the brain or norepinephrine in the brain from SNRIs. I mean, the SNRIs are more specific to the brain as well because they're inhibiting the reuptake at the synapse and not causing like a dump of norepinephrine from the adrenals like you see with the cold shock response or other stressors.

• 22:21David Puder?

  Yeah. So I think that we'll, we'll, we'll get more to this cortisol increases, but may over time you make it more used to it. So your cortisol may not increase.

• 22:33David Puder?

  And shivering occurs when your core body temperature drops. And I would say it's pretty rare at this point for me to shiver at all when I'm in there. But when I get someone new, they're shivering within a couple of minutes and it's, it's very visible.

• 22:51Speaker 01

  Yeah, I was shivering a lot when I started, even like for minutes after. It's like I got so cold and I'm someone who shivers a lot too. Like I, I did the cold plunge back when we, when I got proposed or when I got engaged, we went to a resort that had the hot and cold. And even in the cold, I was shivering even after the sauna. So if you're not used to it, you're going to shiver a lot.

• 23:17David Puder?

  Oh, I had this friend over and we were slacklining and in between slacklining, we were going to the cold plunge, right? And I didn't realize he was completely naive to it. And we ended up doing about 20 minutes because we do, it was hot out. So we do like hot, you know, slack lining for like 10, 15 minutes, getting a cold plunge for like one minute, copy, repeat. Ended up hurting my foot, my toe, and it's still been hurting months later. So I think I couldn't feel how maybe the micro damage from the slack lining because of the cold, but then it kind of caught up to me. So I felt bad for him after I realized he had never even done this before. And I was like, subjected him.

• 24:02David Puder?

  His, his, uh, his willingness to do it was always there. So it was not torture.

• 24:09Speaker 01

  It wasn't forced.

• 24:10David Puder?

  Torture would be awful in cold, honestly. Like if, if you didn't choose to do it, like I could never do this to someone who wasn't wanting to do it. Like they would have to, there has to be full like agreement that yes, I want to try to do this.

• 24:25Speaker 01

  Right. And we'll, we'll kind of get into it. But I think that might be part of the benefit is you want to do this and pushing yourself to do it yourself is probably where the benefit comes from.

• 24:35David Puder?

  I think that this is why it would never work to test animals in cold and to see how like their neurotransmitters or different things are increasing or because it's like that you're essentially torturing that animal.

• 24:49Speaker 01

  Right.

• 24:49David Puder?

  And so you're just getting, go ahead.

• 24:51Speaker 01

  Even just touching the animal, like handling animals, like mice, you see a really profound sympathetic response, stress response. So yeah, I don't think this really lends itself to studying in animals.

• 25:03David Puder?

  Yeah. Okay. So cold water swimming. So cold water swimming, there's a, there's a book I read, Winter Swimming by Susannah Soberg. She's popularized this, uh, she, she did some research on brown fat. We're talking about this. Any thoughts on this, Liam?

• 25:22Speaker 01

  Yeah, I just want to mention like the initial studies for cold water swimming. Most of them are like observational studies of people in Denmark. And that's where Dr. Silver is from. And you know, some of these initial studies were promising. Like they showed some improvements in people's metabolism, like triglycerides, glucose, even cholesterol, their quality of life, well being, their mood, some anxiety and depressive symptoms. But again, most of these studies were just observational, seeing someone how they changed from October into April. And obviously, there's a lot of confounding factors that go into that, like the effect

• 26:03Speaker 01

  of exercise, the effects of socialization, and maybe even a healthy user bias. Like if someone starts to do a practice that they perceive as healthy, then they also change their other behaviors too. Then there's also the effect of being in nature, because that's where most of these studies were conducted, out into the sea. And there is some mental health benefits to being in nature as well. So I think a lot of the book does draw on these initial studies. And I think what's important is that we look at the actual effect of how most people use cold plunges today. And that's through doing it passively, not so much in nature.

• 26:43Speaker 01

  But it's more so just a, the physiological response to cold itself that might be, that we can look at a little bit easier with some of these studies. So I think like with the cold water swimming studies, there's just too many confounders to make any really solid claims about.

• 27:02David Puder?

  Yeah, it's like, there's a lot of positive things that they show, but is it the swimming? Yeah, is it the group socialization? Yes, and, right? It's probably all of the above. So it's hard to isolate it. Also, not everywhere has the capacity to have the cold.

• 27:22David Puder?

  A couple of things I would mention if you're listening to this is don't do this alone.

• 27:26Speaker 01

  Yeah.

• 27:27David Puder?

  It's not a good idea to go cold water swimming alone. You want to go with someone who's experienced, who can rescue you if you have that shock response when you get in the cold. You may want to ease your way into this experience. So there's my disclaimer. Okay, shall we talk about this Kelly and Bird 2021? Improved mood following a single immersion in cold water.

• 27:54Speaker 01

  Yeah, so this study, they looked at a group of participants, 42 of them. This one actually took place in the sea in the UK in November. So the water temperature is about 56 degrees Fahrenheit. And of the participants who went in, about half the group, they went in the cold water and they saw improvements in their mood, marked by increased vigor, increased esteem, decreased tension, decreased anger, decreased depression, decreased fatigue. Whereas the control group, they actually increased in depression by one point. So I thought that was kind of funny. But yeah, so they saw some positive moods.

• 28:32David Puder?

  This is 20 minutes. It's 56. So it's not very cold. 56 for me in terms of what I think. 20 minutes is long, though. And also, the maximum score for these subscales range from 16 to 32. So a two-point decrease on a 32-point scale is not huge. It's not incredibly exciting. This is a very easy study to do because it's like you have this experience. You rate them before and after. Boom, you have your data, right?

• 29:03Speaker 01

  Right.

• 29:04David Puder?

  It's a good preliminary study. I think this study says, look, these people aren't gonna, no one died in this study, okay?

• 29:12David Puder?

  They were able to get people to stand in water for 20 minutes in this study.

• 29:16Speaker 01

  Right. It was like a field trip to the lake or to the sea and then everyone jumped in and they saw what happened.

• 29:22David Puder?

  Okay, let's go on to the next one. Yanko Slovakia at all 2023. Short-term head-out of whole-body cold-water immersion facilitates positive affect and increases interaction between large-scale brain networks.

• 29:41Speaker 01

  Yeah, this study also used somewhat warmer water temperatures. They used 68 degrees for five minutes and there were 33 participants who did this. And they observed immediate improvements in positive affect and also decreases in negative affect according to the PANAS scale. And this was about five points each. So again, not too much of a difference for this scale. And they also correlated some of these changes with changes in brain activity and FMRI, specifically coupling of the medial prefrontal cortex with the anterior insula and the dorsolateral prefrontal cortex decreases coupling with the medial prefrontal cortex and the anterior cingulate cortex.

• 30:24Speaker 01

  So to me, I think like these brain imaging findings tend to be a little bit nonspecific. Like, of course, putting yourself into like a shock experience is going to change your brain activity, but I think the specificity of those changes, I mean, if you do another study similar to this, you're probably going to see like different brain changes. And then of course you can correlate that with the changes in mood. So I'm not sure how much to weigh into these brain changes.

• 30:48David Puder?

  I actually wrote the author on this and I asked some questions. And she said, "The overarching finding of this study is that a five-minute whole-body cold-water immersion changes functional connectivity in the brain. These changes are associated with changes in an emotional state as follows. Focal, strong connectivity between frontal and parietal parts of the default mode network, MPFC and LP, salience network, especially anterior insula, which contributes to proprioceptive

• 31:27David Puder?

  feeling, attentional networks as an indicator of alertness, and posterior part of the executive network, which is controlling decision-making. Increasing this focal connectivity may explain the positive effect of CWI. Self-reported positive effect had a strong correlation with increasing this focal connectivity."

• 31:52David Puder?

  Distributed weak connectivity between multiple brain networks was also seen. Self-reported reduction in negative affect was associated with the distributed, again, equals weak, pattern of neuroactivity. Why is this important? We do not want to see focal connections associated with negative affects. Typically, this would mean increasing in symptom severity. Thank you, Alaa, for responding to me and giving this kind of thoughtfulness, thoughtful reply here. So we'll include this in the handout. All right, let's go to READ@ALL 2023. Cardiovascular and mood responses to an acute bout of cold immersion.

• 32:36David Puder?

  So this is 16 adults immersed for 15 minutes and 50 degrees Fahrenheit. So.

• 32:43Speaker 01

  That's more legit now.

• 32:45David Puder?

  That's, that's getting there. That's legit. Water up to the sternum. I would have liked to see them cover their jugular. You know, the neck because of all the sympathetic.

• 32:56Speaker 01

  The vagus nerve.

• 32:56David Puder?

  The vagus nerve and stuff, yeah. So assessments were conducted pre-immersion, during immersion, which is about one minute and 15 minute time points, and 30 minutes post-immersion and 180 minutes post-immersion. So tell me what they found.

• 33:15Speaker 01

  They found, this was using the same scale as a previous study, that negative affect decreased, but only after 180 minutes post-immersion. And it didn't change immediately during immersion. And then also positive, positive affect did not change. And then looking at the, this box plot of the charts with each individual data point, it looks like there's one individual who had like a really strong response. They had a high amount of negative affect prior to immersion. And then after their immersion, 180 minutes later, they had a reduction of that negative affect. I think a lot of that drove some of these statistically significant findings.

• 33:58Speaker 01

  So I'm not really too sure how strong that this effect is for negative affect.

• 34:04David Puder?

  Once again, this is a one-time event, right? And I think it's possible that this is like, from my experience, it may not be the first immersion that you get the benefit for depression.

• 34:22David Puder?

  It may take repeated and ongoing immersive experiences.

• 34:29Speaker 01

  Yeah, I'm not sure how willing this participant was if they had this much negative effect prior to the exposure. They're probably a little bit nervous about it. It might have been their first time.

• 34:39David Puder?

  Things are trending in the right direction, right? No, no changes in beta endorphin were observed. That's interesting.

• 34:49Speaker 01

  Yeah, and then cortisol was also not changed for the first 30 minutes. So prior to immersion, then 15 minutes after the immersion. And then it actually decreased by 47% after 180 minutes.

• 35:04David Puder?

  I think that's, that's really impressive. That's a big decrease 180 minutes after. Now, that makes me wonder, even before doing the experience, did they have a little bit elevated cortisol because they were stressed out about going in the water for the first time?

• 35:20Speaker 01

  Yeah, exactly. I think there's probably, that's probably a part of the effect that explains it. Yeah.

• 35:26David Puder?

  Okay, the catecholamine hypothesis. Walk me through this.

• 35:32Speaker 01

  Yeah, so this is really, in my mind, some of the most robust findings that you see from these studies looking at the physiological changes. And we know that catecholamines are associated with moon. So catecholamines being dopamine, norepinephrine, epinephrine. And the first study that really demonstrated this to a pretty profound extent was by ceramic et al. in 2000 in a study titled "Human Physiological Responses to Immersion into Water of Different Temperatures." So in this study, they had 10 male subjects sit in a chair in different temperatures of water for one hour. And that sounds pretty incredible, but the temperature again was about 59 degrees Fahrenheit.

• 36:15Speaker 01

  And then there was another condition, 68 degrees Fahrenheit, and then 90 degrees Fahrenheit. So almost like a hot tub. And then they measured the different catecholamine amounts and cortisol. And they found that the coldest water temperature, it actually led to hypothermia to some extent. They dropped 37 degrees Celsius to 35.6 degrees Celsius. And this increased metabolic rate led to an increased heart rate and blood pressure changes. So an activation of the sympathetic nervous system. And they observed plasma norepinephrine and dopamine, they both increased fivefold. Epinephrine remained unchanged. And then they also observed plasma cortisol decreases in each session.

• 37:00Speaker 01

  So even in the control sessions, I think this is kind of tying back into the previous study, how cortisol decreased. Cortisol seemed to be a little bit elevated in all of these different trials. And then they dropped within 120 minutes. And its highest prior to the coldest condition. And this might be related to the psychological distress, like thinking, oh, I'm going to be in the cold water for an hour. That's like, that's pretty intense. And you can see that this group, this group had the highest cortisol was prior to this exposure. So it might be a psychological based increase in cortisol and then later normalized as they calmed down.

• 37:41David Puder?

  Yeah, I think what is most interesting to me here is that the norepinephrine and dopamine increase fivefold. Now, this is peripheral. It's not like we're autopsying people's brains, you know, like, like, so this is peripheral norepinephrine, peripheral dopamine. Yet, you know, we have a lot of meds that increase norepinephrine and dopamine for focus, for depression, for anxiety. And so could this be impactful? I think it does help me focus better. I think it does increase my ability to like engage and zoom in, you know? I had one patient who would take some amphetamine salt in the morning.

• 38:30David Puder?

  And then instead of taking one in the afternoon because it would give him insomnia, I convinced him to do a cold plunge. So he started cold plunging around 1:00 PM. And he said that's helped him continue to computer program and study. That made all the difference. So there's one anecdotal, you know, person.

• 38:53Speaker 01

  It's a case report right there.

• 38:54David Puder?

  Case report. So meanwhile, a more recent study, Almont et al., 2021, showed that norepinephrine, epinephrine, and cortisol can increase with shorter cold plunge sessions. In this study, 12 young men sat in 59 degrees Fahrenheit water, 14 Celsius, for 10 minutes. Cortisol, norepinephrine, epinephrine were each significantly increased and remained elevated for several hours after immersion. This is not that cold. I'm not impressed. I want studies with 45 degrees Fahrenheit. That's what I want.

• 39:38Speaker 01

  Yeah, so I thought like the most interesting thing about this study was that the norepinephrine, epinephrine, and cortisol remained elevated. And this effect is like most strong, like in norepinephrine. I put some charts here from the study and you can see it's far and above the control group. And it remains elevated for about two hours at least.

• 40:02David Puder?

  Let's talk about this. Le Baluoto et al., 2008, I'm sure I'm butchering that name, I apologize, investigated the effect of repeated cold exposure over 12 weeks in 20 female participants, comparing three times per week cold water swimming. This was 0 to 2 degrees Celsius. So this is getting...

• 40:27Speaker 01

  So this is the cold temperature now.

• 40:29David Puder?

  This is...

• 40:29Speaker 01

  Oh, freezing. Like 32 degrees Fahrenheit, like 36?

• 40:34David Puder?

  For 20, uh, let's see, for 20 seconds, cryotherapy for two minutes. Cryotherapy was negative 110 Celsius. The study found that plasma norepinephrine increased two to threefold acutely for each session for the above interventions, and this effect persisted throughout the 12-week period. Interesting.

• 40:57Speaker 01

  Yeah, so even after the participants became habituated to the cold water or the cryotherapy, they still had this increase in orperin effort after each of the sessions. And the same cannot be said about cortisol, where cortisol initially peaked during the first two weeks on the days that they expected to do the cold plunge compared to the control days. These were elevated only for the first two weeks. Then after that, what I think, like you can probably explain, either due to psychological mechanisms or physiological, that they became habituated to the cold and then they stopped having this cortisol response.

• 41:35David Puder?

  Interestingly, in this study, plasma like IL-1 beta, IL-6, TNF-alpha did not show any change after cold exposure. So these are other inflammatory markers, bad markers.

• 41:50Speaker 01

  Right. And one of the biggest claims about cold exposure is that it helps the immune system and it can reduce inflammation. And these are some of the main inflammatory markers that are used in most studies, and this study didn't find any effect.

• 42:05David Puder?

  Which, it's not like I would want this to increase those. You know, drugs that increase TNF-alpha tend to not be very good for mental health.

• 42:15Speaker 01

  Right.

• 42:16David Puder?

  So, yeah, tell me about the next study.

• 42:19Speaker 01

  So this next study was one of the first RCTs. They actually did one study prior to this with non-active controls and they saw a benefit. But this was by Remazuska et al in 2020. So they looked at 92 patients with mild to moderate depression, 17 points on average in the HAMD and 21 to 24 in the BDI. And they were receiving outpatient therapy. So the participants were randomly allocated to the cryogenic temperatures, which was a negative 110 degrees Celsius, which I think is like negative 160 something Fahrenheit and negative 135. So they are exposed to either this or to non cryogenic temperatures in the cryotherapy

• 43:04Speaker 01

  machine. So this was an active control and they did this from for two weeks and they did 10 total sessions. So for about three minutes each and they found that both groups improved on the depressive symptoms of Ham D and BDI. And after one week of the treatment, the cryotherapy group scored on average five points lower on the BDI compared to the control group. But the next week, both of the groups essentially caught up to each other. And there's no difference at two week follow up. But there were some elements or some subscales of BDI that did improve more in the cryotherapy group, such as sadness, loss of pleasure, self criticalness, loss of interest and decisiveness, and lower scores

• 43:48Speaker 01

  on the cognitive affect dimension and the somatic dimension, too. And then they had higher improvements in quality of life and symptoms related to pain, sleep and self acceptance. But again, for this, there's also no changes in systemic inflammatory markers like CRP, IL6, IL10, and oxidative stress like nitroglycerin.

• 44:12David Puder?

  So how much of a decrease in the BDI and in the Ham D?

• 44:17Speaker 01

  So the first week, they went from 23 on average in the experimental group, the cryotherapy group, from 23 to 9.4. And then the next time point, the second week, they actually went back up to 15. And then after two week follow up, they're at 13.

• 44:36David Puder?

  See, that's a huge initial decrease. That's like, that's like really significant.

• 44:42Speaker 01

  Yeah.

• 44:42David Puder?

  Which, which makes you think like, okay, maybe there's a role in like just snapping someone out of the funk. Maybe it's, you're going to need therapy, you're going to need other treatments. But to get someone from a 21 to a 9.4?

• 44:58David Puder?

  That quickly is is pretty significant.

• 45:01Speaker 01

  Yeah, that's actually huge.

• 45:02David Puder?

  And I had a patient who's around seventy, male. And he said he's been depressed. He's not talking as much. He's normally very social. And we decided to do the sauna cold plunge. He didn't want and therapy. Exercise, he was already exercising. He had an immediate change. It was like day one. He was like, whoa, I feel totally different. My wife notices a different. Week one, he comes back and he was like a totally different person. You know, and he's he was what I would call like a total responder. I mean, no medication.

• 45:42David Puder?

  I mean, maybe you could say it was my one hour of therapy I did as well. But no, I think I think it was a maybe a combination. But yeah, first first week he was doing it every day. He was going in the cold plunge for like one minute, heat for two to three minutes. Go back to the cold plunge one minute. I mean, this is an older guy. And so, yeah, that's a big that's a big initial drop, though.

• 46:09Speaker 01

  Yeah, I think it really does have an effect on really pulling someone out of a mental state that they're previously in, kind of like exercise. Like if I if I don't exercise in a day, then I feel a little bit jittery. And I'm sure like many people feel that way, too. And, you know, I think once you start to do something like this, if it changes your mental state, then even if it's like volunteer or not, like it probably is going to have some effect. And sometimes it can be positive. Sometimes it might be negative.

• 46:39David Puder?

  Yep.

• 46:41David Puder?

  Okay. Yeah. Anything else interesting about this study?

• 46:45Speaker 01

  Um, no, but I just want to say like. Broadly, the most profound physiological thing is that we see an increase in norepinephrine. And even though we're not measuring it in the plasma, or we're not measuring it in the brain, we're measuring it in plasma, and norepinephrine doesn't cross the blood-brain barrier, that there's probably an increase in norepinephrine in the brain. And, you know, the extent to which this is important, I'm not sure. But we know that exercise also increases norepinephrine, some of these medications do as well. So I think it's going to be interesting to look at, you know, what is the actual utility behind this? And does that explain a lot of these mood benefits that we're seeing? Or is it more so just like a change in someone's

• 47:29Speaker 01

  psychological response and changing their mindset, like I mentioned?

• 47:34David Puder?

  Yeah, doing something, like doing something hard is probably gonna, it's like a behavioral therapy, right?

• 47:41Speaker 01

  Right.

• 47:42David Puder?

  Yeah. Let's talk about inflammation and immune functioning.

• 47:46Speaker 01

  Yeah, so like these studies weren't seeing any positive benefits on the inflammatory response, like they're not, they're seeing stable inflammatory cytokines. But this is kind of like one of the main claims about cold exposure is that it does change the immune system. So at this point, I'd say like, it's probably not so much, the mood benefits are due to reduction in inflammation, at least at this point, I'd say. But, you know, some initial studies did show that people who did cold exposure had 40% less upper respiratory infections. But again, this was like one of those cold water swimming studies, and it was sort of self-report. But then I think one of the more interesting ones is

• 48:30Speaker 01

  the effect of the adaptive response to a, an infectious agent, like a, one study looked at the injection of a bacterial undertoxin, and this was like Wim Hof and his followers, there were 14 people. And they saw that the people who did the Wim Hof method and cold exposure, they had a lower increase of IL6 in TNF-alpha, so these inflammatory cytokines, and responses under toxin. But I mean, this, this isn't been like a study that's been replicated since then. But I mean, there is, there is still some claim to be made about, you know, the effect of the stress response changing the immune system.

• 49:12Speaker 01

  Like if you do cold exposure and you have a robust stress response and you're increasing oroprenorphine, increasing cortisol, and these are known to modulate the immune system to kind of prepare it for infectious processes. So maybe there could be some case to be made about the stress response from the cold helping to combat infections, but there's really not any studies about this yet. But I, I think at this point, it doesn't seem like there's a robust systemic response, aside from these edge cases, maybe.

• 49:45David Puder?

  Yeah. And going back to our sauna study, we found that there was a significant reduction in pneumonia. And, you know, this was hospital-based pneumonia data that they were looking at. It was a 37% reduced risk of pneumonia with, with the people that were using the sauna four to seven times a week compared to one time a week. There was a 78% reduction in psychotic disorder, which I think a lot of it probably was delirium. This was all types of psychotic disorders in patients who were excluded to have antipsychotics at the beginning of the study. So, you know, was it the cold? Was it the heat?

• 50:29David Puder?

  Was it both? Was it the, the practice of doing something like that over time, right? Because also it's hard to study in these, these, these types of things like, okay, is it, you know, is the cold water swimming? Is it the exercise? Is it the cold and that, having that stress? Is it the sauna and having that sort of positive impact? So.

• 50:55David Puder?

  I would probably say more studies are needed at this point.

• 51:01Speaker 01

  Yeah, definitely. But I think that's gonna be like our general conclusions for a lot of the stuff that we're talking about today. There's just not great quality studies out there. There's a huge need for it. And then one more thing about inflammation that I did want to mention is like, obviously, people use like ice packs. And a lot of people after exercising, they'll do ice baths, like I mentioned with athletes. And it does seem like there could be a potential role for post-exercise inflammation. Like one study, one meta-analysis didn't show an effect, but we know that, as we'll talk about a little bit later, that cold exposure does decrease anabolic signaling, which itself is reliant on inflammatory processes and muscle damage, cell damage.

• 51:47Speaker 01

  And it dampens that response. So there might be some effect for a reduction in localized inflammation. So for like a muscle to reduce the swelling, to reduce the immune response there. But it doesn't seem like there's a systemic response towards cold exposure.

• 52:07David Puder?

  Yeah, good point. So when my kid bumps his head, I'm still putting ice on him.

• 52:15Speaker 01

  Yeah, I think I would. Decreases the swelling and the pain.

• 52:20David Puder?

  You know, there's, I think with the exercise ones, we'll get to it, but it's like with hypertrophy, people are trying to get a little bit of inflammation in your muscles to get that hypertrophy, to get the muscles to increase in size. I think this is saying you may not get as much hypertrophy, but you will get the strength adaptation, which is interesting, right? Is that what we found? That's what we found, right?

• 52:46David Puder?

  Okay, so what about the psychological aspects of cold therapy, mindfulness, overcoming dissociation? Which I would say that dissociation is something that I've thought about. It's like, you know, I could be in a little bit of a dissociative haze, like I said, and it can snap me out of it. I could wake up in a funk, it'll snap me out of it. That dissociative state, kind of the not-quite-fully-present in your body.

• 53:12David Puder?

  We all can have dissociative states. It's not like you have to have like DID or some trauma to have it. If you are overly saturated with distressing topics, you may yourself feel a little bit more dissociative.

• 53:28David Puder?

  I have seen cold exposure help people snap out of a funk. So, in regard to the psychological aspects, what did you want to mention?

• 53:40Speaker 01

  Yeah, I wanted to mention that it does seem like cold exposure is kind of like a mini meditation or like a mindfulness session, because it kind of brings your attention directly to the present moment and to your body. So it increases that bodily connection to your thoughts to the present moment, your attention to that, instead of, you know, whatever goings-on you have in your life that's stressing you out. It really forces you into the present and to think about what you're feeling in your body and to have to calm yourself, like your breathing, instead of being like in gasping when you're in the water, just slow your breathing, calm your breathing like that, that is profoundly relaxing.

• 54:23Speaker 01

  And I just wanted to read some of the quotes from a qualitative study that just came out in 2024 about Danish swimmers, cold water swimmers. They said, "It can be quite meditative to sit there in the water. You quickly forget other things and have a strong focus on being present in the moment, because it's challenging to think about other stuff when you're hitting, where you're getting hit with that cold water constantly, so I don't think much is happening in your head."

• 54:48David Puder?

  Here's another quote. "Sometimes it can be challenging to sit and meditate and not think about anything, but when you get in the cold water..." You just can't think about anything else. It's like the body with the cold and the warmth just forces you to be in the moment. And what a antidote to the world we live in, right? Where it's like, there's so many things pulling for our attention to be fully in the moment, present.

• 55:18Speaker 01

  Right. It's, I, I think, um, I, I think most people should engage in a practice like this that takes their attention away from whatever default setting it was in, uh, thinking about whatever is going on. And then just collapsing them to, to this setting where it's like they're completely in tuck to their body. And then after that, you can, maybe your attention is different and you think about just the things that are more important, like, oh, I have to go exercise or I have to go mock the dog or do something more productive. I think that it gives you an opportunity to do that. But I, I think it also, you need to put it in context where you can allow yourself to do that.

• 55:58Speaker 01

  Like you mentioned that you do some cold exposure when you're feeling dissociated. So it really allows you to give that event to where you can go from one setting and then to a next, or one state of mind to another state of mind. Uh, so I think there is a profound benefit for that. Uh, but unfortunately, there's not many studies that actually address that.

• 56:18David Puder?

  You know, there's, there's two things that come to my mind. One is for, for patients with borderline personality disorder. Uh, part of DBT is to, to grab some ice and hold ice in your hands, maybe like rub it on your forehead. This, this has worked in a number of patients who dissociate. Now, I had one patient who would hold something cold and it would make her dissociate more because it was so unpleasant. So you have to gauge the person, you know? I remember one.

• 56:49Speaker 01

  Yeah.

• 56:49David Puder?

  I have a, I have a freezer down the hall and I had this patient who was dissociating and went down there and had this cold cap that he put on your head. And I was like, do you feel better? She's like, yeah. And I looked at her and I could feel more dissociative than she was before. Like, I can feel someone's dissociation. I was like, do you feel, it's okay if you feel worse? She's like, yeah, I feel worse. I'm like, okay, let's take it off. And I think she appreciated me noticing, you know? She was like wanting to appease me by doing this thing. But then when I, I could tell she was doing worse on it. She stopped and she felt better. So we have to be careful as providers as well at saying things. And then patients do it just, just because they want to make us happy.

• 57:34David Puder?

  That's a risk. Okay, so the first thing is some, some it helps, some it doesn't. Pay attention. Experiment with it. The second thing is, once in a while, I hear of someone jumping into cold water as like a suicide attempt. And then, once they're in the water, they decide they want to live. And I've heard this a number of times. And then it occurred to me as I'm, as I'm thinking about this, like, oh, I wonder if the cold snapped them out of whatever funk they were in. And like, they, you know, it changed how they were thinking about hurting themselves in the moment, you know? So.

• 58:14Speaker 01

  Right. Even like the previous study that we're talking about with brain activity changes. Like, it does change the prefrontal cortex, dorsal out prefrontal cortex. And you're saying that all these regions that are associated with, you know, constructing narratives and what's important to pay attention to. So I think there is something to be said about cold exposure snapping someone out of a certain thought pattern potentially.

• 58:36David Puder?

  Yep. Okay. So the placebo effect, let's talk about this because is it, is there any data to support that this is just a placebo? Right? And we know, we know from placebo studies, if you go back to, I think it was like years ago, I did an episode with Mark Art on placebo. We know that like, if you inject someone with something, it increases the placebo response. If it's a surgery, it increases the placebo response. Right? If, if the pill is a bright color versus white, it increases the placebo response. If it, if it's an expensive pill versus a cold one, it increases the placebo response. So what did the study find?

• 59:21Speaker 01

  Yeah, there's two studies that I wanted to mention. The first is, I think, really interesting. It just came out 2024. It was 21 days of Wim Hof method, which is the cold showers plus rapid breathing. So they didn't use like extreme cold, but they used cold showers, which itself is kind of stressful. And then the active control was warm showers and slow breathing. So the complete opposite of Wim Hof. And they looked at 78 patients with mild depression, a PHQ score of like around 10 to 20. And these were all women. And both groups experienced a 20 to 30% reduction in depression and anxiety. But there are no differences between the groups.

• 1:00:03David Puder?

  And how long were they in the cold?

• 1:00:06Speaker 01

  Uh, I think they were just instructed to go for as long as they could tolerate.

• 1:00:12David Puder?

  And was it a shower or was it an immersion?

• 1:00:15Speaker 01

  It was a cold shower. So for in terms of the duration, they, it looks like they increased throughout the week. They first started with 30 seconds for days one to three, and then one to three minutes for days four to six. And then two to three minutes for the remaining days. Again, for a total of 21 days.

• 1:00:36David Puder?

  And the breathing practice was roughly 15 minutes per session.

• 1:00:41David Puder?

  So that's significant. That's a, that's a real. That, that has an impact in and of itself, right? Sitting there, breathing, slow breaths.

• 1:00:50Speaker 01

  Yeah, it is, it is an intervention and, but you wouldn't think at first that this would cause an antidepressant effect or an anti-anxiety effect. But I mean, it is a type of intervention. So again, is, does that say, is this cold Wim Hof breathing? Is that beneficial or is it just doing an intervention?

• 1:01:13David Puder?

  Also, people, participants were given money. They were recruited through local outreach, newsletters, San Francisco employees, flyers, online advertisers. Okay, so they were given $470 for completion. You know, so I'm always like, okay, are these like?

• 1:01:34Speaker 01

  Let's see incentive.

• 1:01:36David Puder?

  Are these guys, are these people like, oh, I better score high on this coming in? Okay, what is the temperature of the water?

• 1:01:45Speaker 01

  I don't think they reported the water temperature. I think it was just as cold as they could get in their shower.

• 1:01:51David Puder?

  Yeah, I, in California, what time of the year is it? I don't think it was cold enough.

• 1:01:58Speaker 01

  No, it definitely was not. I don't think.

• 1:02:02David Puder?

  I, I don't, and shower is such a different experience than just immersion.

• 1:02:08David Puder?

  But everyone got better. And so I'm thinking it probably was the breathing and the, just being a part of a group, doing something, doing something different. I mean, 15 minutes of breathing. I think it's a mindful activity. So I think essentially you were looking at two different arms of mindfulness. I don't think that the cold was cold enough. Which I think, so it's like, I wouldn't look at this study and say, oh, look, it's a placebo. Cold, cold immersion is placebo because it just wasn't cold enough.

• 1:02:39Speaker 01

  Yeah, that definitely makes sense because you're not going to have the same physiological effects. Like you're going to have some psychological stress going into the shower. If it's cold, where you're not going to see that with the warm showers. So that's like, pretty much the only difference that you'd see is maybe some psychological stress and then overcoming them. But not to the same extent, nearly as much as a cold plunge.

• 1:03:03David Puder?

  And I don't think, what I could say from this is that I'm not sure that the Wim Hof breathing is magical. Compared to just slow, mindful, more like the yoga breathing, which I think is really good. Like that's the kind of biofeedback breathing that people do.

• 1:03:19David Puder?

  You know, that's slow, slow breathing, 15 minutes.

• 1:03:24David Puder?

  Interesting. Okay, well, you guys can look at that study more and if you have other thoughts, let me know. But I'm not thinking that that takes away my... It's not like the placebo was,

• 1:03:38David Puder?

  or the Wim Hof was like five minutes at 45 degrees Fahrenheit, you know, which is kind of like what I would need to see to be convinced that it's just a placebo. Yeah, plus, plus, we know, okay, from the other studies, that the norepinephrine changed when you got to the colder temperatures, but not that, you know.

• 1:04:00Speaker 01

  Not the warmer ones.

• 1:04:01David Puder?

  Not the warmer ones. So it's like, you're gonna see different physiologic brain effects in those colder ranges.

• 1:04:09Speaker 01

  Right. But then again, you can still see like the psychological, but nearly not as much as the, as actual true cold exposure, where you get some of the bottom up effects as well.

• 1:04:22David Puder?

  Okay. So, let's go to theoretical underpinnings of enhanced mood effects.

• 1:04:29Speaker 01

  Oh, I want to talk about one other placebo study first.

• 1:04:31David Puder?

  Okay, let's do it.

• 1:04:33Speaker 01

  So, so this was a recovery, like post-exercise recovery study, where I thought the design here is really interesting, and I think they did a better job at controlling for the placebo effect. So essentially what they did is they used cold water immersion at 10 degrees Celsius, around 40 to 50 degrees Fahrenheit. And they had one group in cold water immersion after a workout, and it had another group at thermo-neutral temperature, so around like 70 degrees Fahrenheit, and then another group that had the same thermo-neutral temperature, the room temperature

• 1:05:13Speaker 01

  water, and then they added a squirt of soap in this water. And they told participants, like, oh, this is gonna help your recovery. So what they found is that only in the control group without the with the one that didn't have the placebo, the one that didn't have cold water, only this group had a reduction in leg strength and higher subjective ratings of pain and reduction in vigor after completing an exercise, a high intensity interval training session.

• 1:05:47David Puder?

  Only in what group?

• 1:05:48Speaker 01

  The control group, the the group that

• 1:05:51David Puder?

  With the squirt of the soap?

• 1:05:52Speaker 01

  Was in the room temperature water. Without the squirt of soap. So the the group with the squirt of soap and the cold water immersion group, both of these groups had reduced pain, increased readiness for exercise, increased vigor after completing a high intensity interval session. So they had less soreness and they also had greater strength compared to the control group.

• 1:06:12David Puder?

  Okay, interesting.

• 1:06:14Speaker 01

  So this So I think this this is more of a placebo response, like more of a definitive placebo response.

• 1:06:22David Puder?

  Try telling every athlete who swears by it, right? That this makes them better.

• 1:06:28Speaker 01

  Right. I mean, like, but it actually might make them better if they think that it is.

• 1:06:33David Puder?

  That's that's the the wildness of our brains, right? The meaning attribution that we give to things changes the thing itself.

• 1:06:42David Puder?

  Yeah.

• 1:06:43Speaker 01

  Yeah, really interesting.

• 1:06:44David Puder?

  I go back to the placebo medications, like they they did this one placebo study where they were looking at for Parkinson's patients, how much placebo increased the dopamine in the brain, and it actually increased it because they told the participants this was going to increase the dopamine in your brain.

• 1:07:03Speaker 01

  And the dopamine increase was associated with reduction in Parkinson's symptoms.

• 1:07:08David Puder?

  Yeah.

• 1:07:08Speaker 01

  And you you also see other mind-body connections with sham surgeries and patients with fake knee surgeries, and they have reductions in pain and they'd never have any complaints. So there is definitely a mind-body connection. You can alter the immune system, maybe change how your body repairs itself or how you perceive the the pain signals from your body. So there is definitely a placebo effect.

• 1:07:35David Puder?

  Yep. And also think about Patients that are given a nocebo effect, like when doctors say things like, "You, I'm looking at your x-ray and you're bone on bone. This is gonna hurt the rest of your life." And it's like, "No, don't say that. It's never bone on bone." Like, don't say that.

• 1:07:53Speaker 01

  Yeah.

• 1:07:54David Puder?

  Like, it's an awful thing to start believing that you will never get better. That's the worst. Like, you wanna... Yeah, okay.

• 1:08:03Speaker 01

  It's good for getting knee replacements, though.

• 1:08:07David Puder?

  It's good for the industry. Okay, let's talk about the theoretical underpinnings for enhanced mood effects.

• 1:08:14Speaker 01

  So again, you have a profound increase in norepinephrine if you actually engage in a cold, a cold plunge, or very cold cryotherapy. And this, this could have some implications for anxiety. There are some theories about the monoamines still being important for anxiety. Maybe for PTSD, there, there might be elevated norepinephrine. So some of the arguments for cold exposure could be that it kind of calibrates the signal to noise ratio on fear and anxiety. So if someone has too much anxiety when they're not supposed to due to, you know, their norepinephrine increases when it's not supposed to.

• 1:08:57Speaker 01

  If you give your body a really strong stimulus, like a big stressor, exercise, or cold exposure that increases norepinephrine, then these other things that typically cause anxiety in this, in this person, maybe that doesn't cause anxiety because they recalibrated the norepinephrine system. That, that's pretty much the theory behind it.

• 1:09:18David Puder?

  Yeah, that, and that's, um... We're seeing the opposite of that with kids that do nothing stressful. And they, they can live years of their life with having no real stress in their life. And then the normal stresses of life are overwhelming.

• 1:09:36Speaker 01

  Right.

• 1:09:36David Puder?

  And so perhaps this is a way of doing something stressful progressively that then teaches your stress system to recalibrate. I think that's possible. I think the norepinephrine, the dopamine increase as well, right? Both of these... Are for medications to improve focus, depression. You know, we give Wellbutrin, we give Atomoxetin. Sometimes these help with mood, with focus and addiction. Right? And so, yeah, maybe that's part of it. Maybe there's other mechanisms we don't know yet. Right?

• 1:10:16David Puder?

  I mean, I feel like when you look at like the field of study for a lot of different things, it's a lot more extensive than this field of study.

• 1:10:25Speaker 01

  But I think the claims that are being made like relative to the amount of evidence, I think it's actually incredible. Like the claims that are being made on podcasts and the anecdotes out there. And there's really not much evidence base to go off of, which I think this is, I think it is really exciting because of all these anecdotes out there. And there is a potential mechanism to explain how can improve your mood.

• 1:10:52David Puder?

  I would say the one other patient that really sticks out to me that has really benefited is this young 39 year old female who had depression, real episodes of depression, like discreet, major depression would get severe. She was on, I think Zoloft 50 and it wasn't doing the full effect this time. And so I said, well, you know, this, you live by a river. Why don't you just jump in the river three to four minutes every day and see if that's helpful? So she comes back one month later and you know, usually when I give recommendations, I don't expect a hundred percent follow up, follow through.

• 1:11:35David Puder?

  She, she had a hundred percent commitment to this and she was in a place where it was cold enough to, to get the benefit. And she, she said it was like a night and day difference. It was like, it was like the veil that was keeping her kind of like in a kind of a haze was completely gone and she was back working.

• 1:12:01David Puder?

  Doing business ventures. And this is someone who had done a lot of therapy. She was on medication, she was in therapy. But this seemed to be like very pronounced. And she continued doing it. And she was able to get off of the antidepressant after like about a year. And, you know, swears by it. So I don't know. There's not, there's a couple of case studies that I have, right? That's one. This older gentleman is one. My own experience. But I think I agree with you that there just isn't a lot of data. And so I'm very hesitant to be too exuberant.

• 1:12:40Speaker 01

  Right.

• 1:12:41David Puder?

  Because, you know, the last thing we need is to think that this is so much better than therapy or something for, you know, it's like, no.

• 1:12:52Speaker 01

  No, I think it could be like as an adjunct, similar to exercise. Where you have the, the body benefits, you have the, the mind benefits too.

• 1:13:01David Puder?

  In my own mind, I would put exercise above this in the hierarchy of like things. Because exercises, there's so much data. There's huge meta-analysis. The effect size is very significant. For mild to moderate depression, it seems fairly equivalent to medication, to therapy. I would say therapy probably has a bigger effect size when you're doing a big dose of therapy. When you, when you're doing 50 sessions of therapy, you're getting 75% of people out in remission for moderate depression. Okay. So, yeah, so maybe it's the Norman Efrain. What is it less likely to be the mechanism?

• 1:13:42David Puder?

  Cause there's some other sort of ideas about how this might be improving things. What, what is less likely in your mind?

• 1:13:50Speaker 01

  I think it's less likely the cognitions about, you know, how someone perceives the world around them. Like, I mean, to some extent, you are changing the way that someone thinks.

• 1:14:05Speaker 01

  Through like this acute stressor, like you're capturing their attention, collapsing it, changing it from one state to another, but I don't think it really changes a lot of the cognitions about about oneself potentially, or like someone's propensity to misperceive a threat like in you've seen PTSD, or more negativity like you see with anxiety and depression. So I think those things need to be targeted through therapy. And this is more so just something that can give someone a little bit of a boost to go throughout their day and like have a snowball effect potentially, at least in cases of like mild to moderate depression potentially.

• 1:14:45David Puder?

  Yeah, I would say if you have deep rooted, childhood, attachment based, traumatic events that have led to beliefs about yourself, beliefs about others, you know, that's not gonna help us. Right? It's a, it's a lot of therapy, really. It's like transference focused therapy, mentalization based therapy, you know, these, these types of therapies where you get into the deep interpersonal, the depth work, reflective function, work on the reflective function, stuff like that. Initially, I was excited about brown fat until you dissuaded me of my excitement. I was like, I was in the cold plunge. I was

• 1:15:30David Puder?

  like thinking to myself, my white fat is turning to brown fat. Brown fat essentially just says more mitochondria. I was visualizing the, the white fat turning into brown fat.

• 1:15:41Speaker 01

  Your A1C going down too.

• 1:15:42David Puder?

  My A1C going down. I was so excited about this. And then you kind of, you popped the balloon of my excitement. Tell me about that.

• 1:15:52Speaker 01

  Yeah. So brown fat is this tissue, like you mentioned, that has more mitochondria in it. And it's typically seen more so in infants because infants don't have the same like thermogenic effects. They have a, they have a larger surface area to volume ratio so that they lose heat. So they need more ways to produce heat in their own body. Other small animals also have more brown fat. So if you're looking at a study of like mice and seeing like, oh, they have improved, improved insulin sensitivity in mice. Well, the mice also have, the mouse also has a relatively higher percentage of brown fat. So in the mitochondria of brown fat, there is an uncoupling protein that allows it to uncouple the electron gradient

• 1:16:36Speaker 01

  that allows it to generate heat essentially. And this is what allows for, you know, babies and these small animals to to have heat when they otherwise are losing a lot of heat. And people who are advocates of cold exposure, they claim that because you're activating the brown fat, which there are some studies that have shown that brown fat activity does increase during cold exposure, that you're going to be burning more calories because you're uncoupling the mitochondria and you're generating, you're increasing the uptake of these mitochondria of glucose and other nutrients so that you're burning more calories than you otherwise would from just sitting there.

• 1:17:18Speaker 01

  And they think that if you increase your relative amount of brown fat in your body through cold exposure, then you can just burn more calories throughout the day. And a lot of this actually came from this discussion of brown fat recently. It came from Dr. Soberg's initial study on looking at a group of cold water swimmers. She compared cold water swimmers to controls that had about the same physical activity levels. And they looked at the relative amounts of brown fat and the activation of brown fat when they were in a cooling condition. They put a cooling blanket on them that circulated cold water on them.

• 1:18:02Speaker 01

  And what she found is that there is a 500 calorie difference in daily resting energy expenditure. And so this whole narrative about brown fat allowing you to lose 500 calories, like 500 calories every single day is a difference of one pound of fat, like 3,500 calories equates to one pound of fat. So this would mean you could be a lot leaner if you activate your brown fat. But the problem, one of the main problems with the study is that this 500 calorie difference, it comes from an extrapolation of when they were doing the cold exposure. So brown fat's only going to be active when you're cold. So it's more active in the winter, it's more prevalent in the winter.

• 1:18:46Speaker 01

  And people who have less body fat because they don't have as much fat to insulate them. So in the study, the cold water swimming group had less body fat overall. And they had a more higher active brown fat during this 10 minute session or 30 minute session of cooling. And what they found is that equated to a 10 calorie difference in resting energy expenditure during that 30 minutes. So when you extrapolate that 10 calorie difference in 30 minutes to 24 hours throughout the days, which is what they did, that's 480 calories or about 500 calories throughout the entire day. And that's not at all the difference in energy expenditure between the groups.

• 1:19:30David Puder?

  You broke my heart, Liam. I was imagining myself burning 500 more calories per day.

• 1:19:37Speaker 01

  Right. I mean, it is just kind of absurd, like how much brown fat is actually on the average person. And in one, in one of these participants in the cold water swimming group, they didn't have brown fat. The swimmer did not have brown fat, so they got rid of the subject. So brown fat is very like dependent on the individual, a lot of it is genetic. And even still, it's only 50 to 300 grams, so up to a pound at most on the average person. And to think that one pound of tissue can burn that much calories is insane, especially when you compare it to the brain, which the brain takes up probably about 20% of your body's total calories, your basal metabolic rate.

• 1:20:20Speaker 01

  You compare that to muscle, you can have pounds of muscle that take up so much glucose, like that's a huge driver of your metabolism. And then you think that one pound of tissue, just because it has like more mitochondria, it's not going to really change the needle on anything.

• 1:20:39David Puder?

  Yeah, I think this is where I come back to, you know, if you want to be metabolically healthy, the priority is probably strength training, cardio. I can't see that being a lose situation for someone.

• 1:20:56Speaker 01

  Right.

• 1:20:57David Puder?

  Yeah.

• 1:20:58Speaker 01

  Yeah, you get the metabolic benefits, the health benefits, mood benefits.

• 1:21:05David Puder?

  Yeah, the total, I mean, the other thing is like 500 calories a day. If you were cold all day long,

• 1:21:15David Puder?

  like, no one is in a cold situation all day long.

• 1:21:19Speaker 01

  Yeah, and I think one of the interesting things, like, even if you assume that you're really maximally uncoupling the mitochondria, the brown fat, say it's working all day, you're not going to lose that much weight. Because there's one fat loss molecule that had been studied since the 20th century is called D N P. And even some supplements have it today and some bodybuilders use it. This uncouples the mitochondria like you'd see in brown fat, but uncouples it in all the tissues in the body. And so even then, this leads to a weight loss of about one pound per week from like a relatively moderate dose.

• 1:22:05Speaker 01

  So that's assuming, so comparing that to brown fat,

• 1:22:10Speaker 01

  you know, they're assuming that the brown fat is that metabolic. They after that, it's not the case.

• 1:22:16David Puder?

  Yeah, and I think like, if you want to think about like, insulin, glucose health, getting, getting glucose from your meal into your muscles, the best thing is to go for a walk, to do a little bit of exercise after every meal or before every meal for about five to 10 minutes. I mean, that has a huge impact. And I would say much better. So me and the kids will go jump on the trampoline.

• 1:22:42David Puder?

  For half an hour after like dinner. And I feel like that's probably a much bigger win despite me wanting this to be a thing.

• 1:22:50Speaker 01

  I know. It sounds like it'd be nice to just sit there for two minutes and kind of rough out or sit out the cold and then have like a lose a pound a week. That'd be awesome, but it's never that easy.

• 1:23:04David Puder?

  Yeah. Okay. So cognitive performance. How is cognitive performance changed by cold exposure?

• 1:23:14Speaker 01

  Yeah, this systematic review was pretty surprising to me. They looked at 18 studies comprised of eight studies that looked at the effects of cold air exposure. So not that convincing. And then also 10 studies that looked at cold water immersion. And they looked at different cognitive performance measures like working memory, executive memory, processing speed. And they saw that in 15 out of 18 experimental studies that cold exposure within the minutes to hours after actually reduced processing speed and executive function. And then working memory and attention seemed to, it was dependent on the study, but some showed deficits,

• 1:23:57Speaker 01

  some showed improvements. So in effect, like, and this is kind of my experience too, the couple of times that I have done cold exposure, is that I did feel a little bit slower. And I did feel like I was losing my train of thought a little bit more. And but I think the main thing from this study is that a lot of these people were naive to cold exposure. So I think over time, you might get some some more benefits to it as your stress response kind of dampens a little bit. You get less cortisol, maybe less norepinephrine, because we know the these, the stress response is not supposed to like help you increase your executive functioning.

• 1:24:36Speaker 01

  So being more stressed might actually reduce some markers of cognitive performance like you see in these in these studies.

• 1:24:46David Puder?

  Yeah, I think it may be person-specific, you know? And also, I would say, when you look at like, atamoxatine, norbenepred reuptake inhibitor, these are given for three to four weeks before there's an improvement. So there could also be epigenetic phenomena that hasn't fully been studied. So I would say more research needed, but for someone like myself who says, hey, if I'm in a dissociated state, it really takes me out of it nicely. Whereas some of my patients, maybe it makes it worse. So it's kind of like you have to gauge the person.

• 1:25:27Speaker 01

  Right.

• 1:25:28David Puder?

  Yep. And let's talk about safety precautions. Risk of arrhythmias because of that high sympathetic/parasympathetic activation. I would say, you know, even this morning when I got in, I could feel like a couple palpitations, you know? So maybe if they are at risk for Afib, or they've had a history of arrhythmia, be a little bit more cautious. Yeah, any thoughts on that?

• 1:25:53Speaker 01

  Yeah, so there's like two mechanisms that people think that cold exposure might cause arrhythmias, and that's, like you mentioned, the concurrent parasympathetic and sympathetic activation. And you only get really the parasympathetic if you get the vagus nerve submerged. So that's submerging your neck and your face, and that's called the dive response. And this is often used in patients with supraventricular tachycardias. They're told to put their face in really cold water to try to get the vagus to calm the heart. So the concurrent activation of that might be some effect.

• 1:26:34Speaker 01

  And then also, the arrhythmia might be due to hypothermia as well. So hypothermia.

• 1:26:41Speaker 01

  It can cause arrhythmias and this is most dangerous with the after drop. And so the after drop is when you're in the cold for so long that the blood in your arms and legs, because they're vasoconstricted, it can kind of pool in your arms and legs and become really, really cold. And you know, your, your core body temperature will continue to drop after you get out because this blood after, after you get out, there's less vasoconstriction, the blood from your arms and legs, the cold blood can mix with your core blood that has been warm and that can decrease your core body temperature further and then lead to hyperthermia. And that can lead to arrhythmia as well.

• 1:27:23Speaker 01

  So in any patient who has cardiovascular disease, whether that's ischemic heart disease, heart failure, or things like long QT syndrome, they're at higher risk for arrhythmias and maybe ischemic events. And then anyone who's in the cold for so long, they're also at risk for arrhythmias.

• 1:27:45David Puder?

  Interesting. Yeah, I, um, I would say that being said, in that Finland cohort, when they followed people for, for years who were using the sauna and maybe finishing with something cold, these people had lower risk of heart disease, lower risk of stroke, lower risk of all cause mortality. So you have to, you have to know the risks, but also the benefits. Okay.

• 1:28:13Speaker 01

  Right. And I think one like main difference about cold exposure compared to exercise and sauna too, is that in exercise and sauna, it's a gradual ramping up of your, your sympathetic nervous system. So your heart rate is slowly ramping up, whereas with cold, it's all of a sudden, like it's a, it's a shock. So it is a little bit of a different mechanism, but if you're a healthy person who does not have any. Arrhythmias or any heart disease, and I think it probably is safe. As long as you have someone there with you and they're not going from never having done cold exposure to ice cold water, then maybe I think it's probably safe to do so.

• 1:28:58Speaker 01

  But again, consult your doctor.

• 1:29:01David Puder?

  Consult your doctor, yes. This is not medical advice. This is medical, this is information for informational purposes only.

• 1:29:09Speaker 01

  Exactly.

• 1:29:11David Puder?

  I actually will not go underwater with my head for more than like 10 seconds if I'm alone. Some people may, but I personally, that's where like, I'm like, uh, I'm gonna wait to do this with a friend.

• 1:29:23Speaker 01

  Right.

• 1:29:23David Puder?

  Okay, so recommendations and future direction. What I was thinking about is imagine someone listening to this and they're like, you know, I wanna do a randomized controlled trial. Feel free to reach out to me or Liam so we can consult with you, so we can talk about it. I think it's a great idea. I think someone young who's listening to this should consider doing it. We were even talking about like, man, I would do a GoFundMe for that. Like, I wanna see a really nice randomized controlled trial on this, like multi-site. Let's go. Liam was even thinking about doing it for a second.

• 1:29:56Speaker 01

  I mean, yeah, if I could get funding, I think that's probably the hardest part. But I know there are a lot of podcasters who do philanthropic work for like mental health treatments. So I think this could be, if someone is really interested in that, they could try to search out through those avenues. Because this is really something that the benefit to harm ratio is, I think, really positive. Like, it's, it could be a really good benefit at a low cost, a low harm to someone. So I think it's something that a lot of people could use on a regular basis.

• 1:30:32David Puder?

  Yep. I think for future randomized controlled trials, my thought would be somewhere around 45 degrees Fahrenheit, three to five minutes, maybe start it to build it up. And then have a control group, which is probably more like 75 degrees, so it still feels maybe cold. And you have to control for any group exposure. So if you have a group doing it together, you have to have two groups doing it both the same time. You can't just have a waitlist control. So you have that group event controlled for. I think I would do the cold plunge rather than cold swimming because it would be hard to control for the exercise aspect.

• 1:31:11Speaker 01

  Yeah.

• 1:31:12David Puder?

  Unless you would have them swim in a normal pool, which I think is also possible. So if you're doing some cold water swimming to have like two different environments, one being a normal pool for swimming, one being a, you know, a cold pool type of thing. So those are some of my thoughts right off the bat. And then I also want to, I would want to do it for like six to eight weeks, you know? Maybe then you get to see the kind of the epigenetic phenomenon that would happen.

• 1:31:45Speaker 01

  Right. You see how they change in response to the cold by habituating to it. Because like I said, the cognitive effects, they might go away after a while, like the decreases in working memory performance and everything.

• 1:31:59David Puder?

  I'd also do more moderate depression rather than just mild. I'd want people on, you know, not just like a very low level of depression, more moderate to severe.

• 1:32:12Speaker 01

  Yeah. I think it would be cool to also measure like norepinephrine, dopamine, the monoamines, cortisol, and then also measures of like self-efficacy and seeing if that has any moderating effects on the treatment response. Like if someone believes that the practice has been beneficial for them, or, you know, if it helps them get through their day, then maybe that can explain some of the antidepressive effects of it.

• 1:32:38David Puder?

  Yep. I go back to the, the study that they did where there was a drop in that Beck depression inventory that was significant, even in the first week, kind of plateaued out with the other group, but that first drop was, wow, that's very interesting. So maybe as an adjunct for overall treatment, just to get someone started on depression. But this is, it's so early and we only have one study. It's like before I recommend everyone to do something on this podcast, I try to make sure it's like. Really studied out, otherwise, you know, it's like premature, premature over excitement. It's not what I'm about, so.

• 1:33:21Speaker 01

  Exactly. I mean, as clinicians, we have to like really make sure that what we're recommending has gone through the rounds in research and shown some benefit before we can actually claim it. Because a lot of the podcasters, like, they don't have that, that responsibility to the patients. They can pretty much just say whatever they want, as long as it garners attention and some traction, then they're gonna, they're gonna have some benefit to themselves. So, yeah, as clinicians, we have a higher responsibility for our patients.

• 1:33:55David Puder?

  Yep. There was a, a lot of people that recently came out with this statistic that exercises one and a half times better than therapy and medications. And it's like, no, that's not what the study said. It is very catchy, you know, are we looking at severe depression? No. Are we looking at, you know, the same level of control groups? No. So, yeah, it's, we have to be careful because then, you know, the public starts to get kind of like, oh, don't go to therapy, go cold plunge. Like, that would be a nightmare. If that's your takeaway from this, like, oh, my gosh, like, please, please go to therapy.

• 1:34:37David Puder?

  Please do the hard work. You know, if you have severe depression, you may need medication and therapy, and you may need a bunch of other things as well, like exercise and getting rid of processed foods. That's helpful. And maybe try this, sure. But it's like, I don't think there's only one type of treatment that's going to supersede things that we know work and know, we know work really well. So.

• 1:35:07David Puder?

  All right, sir. Thank you for coming on, Liam Browning. This is amazing. We appreciate you. The handout is on psychiatrypodcast.com. You can get CME, Continued Medical Education, for this. And I'm excited to have you on in the future. Maybe we'll do an episode on dating and the difficulties of dating in this modern time. People, what would you like Liam to dive into next? Please let me know.

• 1:35:33Speaker 01

  Yeah, I'm open for anything. Yeah, thanks for having me back on. And again, if someone has any ideas on how we can initiate a trial for cold immersion, I think that'd be awesome to get connected and see if we can get something going.

• 1:35:51David Puder?

  Awesome. All right, we'll go from there.

• 1:35:54Speaker 01

  Thanks.