Essentials: Cold & Heat Exposure for Metabolic Health | Dr. Susanna Søberg

Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science based tools for mental health, physical health, and performance. I'm Andrew Huberman and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. And now for my discussion with Doctor. Susanna Soberg. Doctor. Susanna Soberg, welcome. Thank you. So great to have you here. For many years, I've been interested in cold thermogenesis, and you're bringing so much quality information about this area that for a long time I think was kind of niche and is now becoming more and more mainstream. So my first question, is there any way that we can start to gauge what is the best way to approach a deliberate cold exposure protocol? I mean, should it feel uncomfortable? If the temperature is very cold and you feel that you also feel very cold, then you should stay in the water a little bit longer. So I think it's just you should get uncomfortable cold. So as long as you get uncomfortable cold, it's cold enough and you get this what we call the cold shock. So the cold shock is activation of your sympathetic nervous system and these activation of the cate cholamines. Does the shock mean that I'm having trouble controlling my breathing? Is that a good gauge? Yeah, you can say so because that's kind of like how we define it. So you hyperventilate, so you have a faster breathing rate. So that increases also because you activate your gasping reflex if you are new to this. But if you are adapted, it kind of subsides with time and with adaptation. So what you can do is that you can train this cold exposure and you can kind of like get adapted to it. So you don't have this hyperventilating response every time you go out in the cold water. So this is like building up your resilience, up your adaptation is going to make this shock subside a bit. So it's always harder in the beginning, but you should do hard things, right? You shouldn't think about cold water and cold water immersion as something that is comfortable. It should be hard because that's the point of it, right? If you enjoy it, yeah, then I'm I'm thinking something is wrong. It's not right. You should not enjoy it. What are the differences in terms of impact short term and perhaps even long term between cold showers, cold plunge to the neck? That could be in ice water or just very cold water, immersion with dunking one's head and then coming up, because obviously people have to come up for air at some point, and then simply being outside on a cold day in shorts and a T shirt or something of that sort. So there are different outcomes because they are very different exposures of the cold to your cold receptors in your skin. So the more you can say you …