Harnessing the Power of Cold: A Guide to Deliberate Cold Exposure
Eleven minutes a week is enough to deepen your brown fat, sustain dopamine for hours, and build the kind of resilience that extends well beyond the cold itself.
Video·The Proof with Simon Hill·12 min read·June 2026
Dr. Andrew Huberman on brown fat, the 11-minute weekly protocol, and why getting uncomfortably cold is one of the most productive things you can do for your metabolism.
What Brown Fat Actually Is
Not all fat serves the same purpose. Brown adipose tissue — what researchers call brown fat — is fundamentally different from the subcutaneous layer most people hope to reduce. Under a microscope it appears dark, almost russet, because it is dense with mitochondria. Those mitochondria are metabolic engines, generating heat and driving energy expenditure at rates the body's other fat stores cannot approach. Brown fat is not storage but infrastructure — active, responsive, and critical to how efficiently the body runs.
The tissue concentrates in specific zones: around the clavicles, along the upper back, close to the heart, and flanking the liver. These locations are not incidental. Proximity to major circulatory pathways allows brown fat to influence warmth regulation and energy expenditure across the entire body. Think of it as a distributed furnace — always on, always converting fuel into heat. Its strategic placement means even modest increases in brown fat activity produce effects the body feels broadly, from core temperature to resting metabolism.
Children are born with an abundance of it. The density of brown fat is part of why infants regulate temperature differently from adults — their metabolic furnaces burn bright from the start. As we age, that density declines. The body reads diminished cold exposure as a signal that the high-metabolic tissue is no longer necessary, and mitochondrial density within brown fat gradually decreases. Resting metabolism edges lower — not because the tissue is gone, but because it is no longer being stoked.
Think about the brown fat as like an oil in a candle that allows it to burn hotter and longer.
Deliberate cold exposure is one of the most direct ways to reverse that trajectory. When the body encounters uncomfortable cold with regularity, it responds by increasing mitochondrial density within existing brown fat — not by growing more fat, but by making the tissue it already has more powerful. The depot does not enlarge; it deepens. A denser brown fat store burns more fuel at rest, generates more heat, and gives the body a stronger metabolic foundation. This is adaptation at the cellular level, made available through a deliberately simple stimulus.
What makes this significant is the proportionality of the response to the stimulus. The body does not require extreme cold or lengthy sessions to trigger the adaptation. It requires discomfort — genuine, controlled discomfort — applied consistently enough to register as a signal worth responding to. This is the essence of hormesis: a deliberate stressor prompts the body to emerge stronger and more resilient than it was before that stressor was applied. Brown fat enrichment is one of the cleaner, more direct expressions of that principle in human physiology.
The mechanism is elegant in its logic: cold makes the body work harder to stay warm, and in doing so, it builds the very tissue that makes future cold more manageable. Each session refines that tissue, incrementally raising its metabolic ceiling. Adaptation and resilience, made tangible through deliberate practice.
i started off my career studying thermal i started off my career studying thermal regulation that's what i did as an regulation that's what i did as an regulation that's what i did as an undergrad and so i have a deep love of undergrad and so i have a deep love of undergrad and so i have a deep love of that literature um we have a storage of that literature um we have a storage of that literature um we have a storage of of healthy fat in our body called brown of healthy fat in our body called brown of healthy fat in our body called brown fat which is literally brown under the fat which is literally brown under the fat which is literally brown under the microscope because it's rich with microscope because it's rich with microscope because it's rich with mitochondria think of it as the oil in a mitochondria think of it as the oil in a mitochondria think of it as the oil in a candle it allows you to feel warm in candle it allows you to feel warm in candle it allows you to feel warm in cold temperatures and it acts as a cold temperatures and it acts as a cold temperatures and it acts as a furnace for your metabolism it's furnace for your metabolism it's furnace for your metabolism it's generally um enriched around the generally um enriched around the generally um enriched around the clavicles upper back and around the clavicles upper back and around the clavicles upper back and around the heart a little bit around the liver it's heart a little bit around the liver it's heart a little bit around the liver it's not the blubbery fat that people not the blubbery fat that people not the blubbery fat that people generally want to have less of it's a generally want to have less of it's a generally want to have less of it's a it's an endogen it's a deep deep tissue it's an endogen it's a deep deep tissue it's an endogen it's a deep deep tissue fat fat fat uh it's really healthy children have a uh it's really healthy children have a uh it's really healthy children have a lot of it you tend to lose it over time lot of it you tend to lose it over time lot of it you tend to lose it over time unless you do cold exposure deliberate unless you do cold exposure deliberate unless you do cold exposure deliberate cold exposure is one way to enrich the cold exposure is one way to enrich the cold exposure is one way to enrich the amount of brown fat you get a a stronger amount of brown fat you get a a stronger amount of brown fat you get a a stronger furnace um and there's some wonderful furnace um and there's some wonderful furnace um and there's some wonderful science on this uh published recently in science on this uh published recently in science on this uh published recently in cell uh cell reports medicine by the cell uh cell reports medicine by the cell uh cell reports medicine by the first author is um susannah soberg um first author is um susannah soberg um first author is um susannah soberg um from denmark and it's really amazing from denmark and it's really amazing from denmark and it's really amazing work what what they showed is that work what what they showed is that work what what they showed is that 11 minutes a week 11 minutes a week 11 minutes a week divided up into a couple sessions of two
divided up into a couple sessions of two divided up into a couple sessions of two to three minutes to three minutes to three minutes of deliberate cold exposure of deliberate cold exposure of deliberate cold exposure increases the density of brown fat in increases the density of brown fat in increases the density of brown fat in adults and allows them to feel more adults and allows them to feel more adults and allows them to feel more comfortable in cold temperatures when comfortable in cold temperatures when comfortable in cold temperatures when they're just walking around okay but they're just walking around okay but they're just walking around okay but also when they put themselves into this also when they put themselves into this also when they put themselves into this deliberate cold and i'll talk about how deliberate cold and i'll talk about how deliberate cold and i'll talk about how cold in a moment cold in a moment cold in a moment that then they achieve much bigger that then they achieve much bigger that then they achieve much bigger increases in core increases in core increases in core resting metabolism resting metabolism resting metabolism improvements in blood lipid uh blood improvements in blood lipid uh blood improvements in blood lipid uh blood lipid and and insulin management lipid and and insulin management lipid and and insulin management profiles and there's some other positive profiles and there's some other positive profiles and there's some other positive effects like improved mental resilience effects like improved mental resilience effects like improved mental resilience so a lot of positive effects so a lot of positive effects so a lot of positive effects really wonderful study done in humans really wonderful study done in humans really wonderful study done in humans right right right because we want to distinguish between because we want to distinguish between because we want to distinguish between mouse working when you say increased mouse working when you say increased mouse working when you say increased density of brown fat so that's not to be density of brown fat so that's not to be density of brown fat so that's not to be confused with increased body fat confused with increased body fat confused with increased body fat no no increased density so that the no no increased density so that the no no increased density so that the mitochondrial density of the brow think mitochondrial density of the brow think mitochondrial density of the brow think about the brown fat as like an oil in a about the brown fat as like an oil in a about the brown fat as like an oil in a candle that allows it to or that allows candle that allows it to or that allows candle that allows it to or that allows it to burn hotter and longer yeah it to burn hotter and longer yeah it to burn hotter and longer yeah so so so so that's one so that's one so that's one that's one um aspect the other um
that's one um aspect the other um that's one um aspect the other um so 11 minutes per week so what was this so 11 minutes per week so what was this so 11 minutes per week so what was this involved well a lot of people say okay involved well a lot of people say okay involved well a lot of people say okay do i need to get into an ice bath no you do i need to get into an ice bath no you do i need to get into an ice bath no you need to get uncomfortably cold for 11 need to get uncomfortably cold for 11 need to get uncomfortably cold for 11 minutes a week that could be done with a minutes a week that could be done with a minutes a week that could be done with a cold shower that can be done by getting cold shower that can be done by getting cold shower that can be done by getting into an ice bath that could be done by into an ice bath that could be done by into an ice bath that could be done by getting into the ocean that can be done getting into the ocean that can be done getting into the ocean that can be done by getting into a lake that could be um by getting into a lake that could be um by getting into a lake that could be um it is not important how you get cold you it is not important how you get cold you it is not important how you get cold you could even put ice packs on your on your could even put ice packs on your on your could even put ice packs on your on your neck or in your whatever in your your neck or in your whatever in your your neck or in your whatever in your your pants get cold people do that pants get cold people do that pants get cold people do that uncomfortable you get uncomfortably cold uncomfortable you get uncomfortably cold uncomfortable you get uncomfortably cold how cold depends and people always say i how cold depends and people always say i how cold depends and people always say i want to give me a number well what's want to give me a number well what's want to give me a number well what's uncomfortable to you is not going to be uncomfortable to you is not going to be uncomfortable to you is not going to be uncomfortable to me and vice versa so uncomfortable to me and vice versa so uncomfortable to me and vice versa so uncomfortably cold and then the uncomfortably cold and then the uncomfortably cold and then the the key thing is that it needs to be the key thing is that it needs to be the key thing is that it needs to be safe right i mean you're not going to safe right i mean you're not going to safe right i mean you're not going to jump into 30 degree fahrenheit water jump into 30 degree fahrenheit water jump into 30 degree fahrenheit water you're gonna your heart will stop right you're gonna your heart will stop right you're gonna your heart will stop right so you you're going to try and get into so you you're going to try and get into so you you're going to try and get into chilly chilly chilly water that you want to get out but you water that you want to get out but you water that you want to get out but you can calm yourself and stay in for that can calm yourself and stay in for that can calm yourself and stay in for that period of two to three minutes period of two to three minutes period of two to three minutes sometimes it you'll be a little colder sometimes it you'll be a little colder sometimes it you'll be a little colder and other times you'll be a little and other times you'll be a little and other times you'll be a little warmer so you don't want to obsess about warmer so you don't want to obsess about warmer so you don't want to obsess about this there's one study that was done this there's one study that was done this there's one study that was done having people submerge themselves in
having people submerge themselves in having people submerge themselves in water of about 60 degrees which is not water of about 60 degrees which is not water of about 60 degrees which is not particularly cold 60 degrees fahrenheit particularly cold 60 degrees fahrenheit particularly cold 60 degrees fahrenheit but they did it for 45 minutes so it but they did it for 45 minutes so it but they did it for 45 minutes so it could also be being in kind of you know could also be being in kind of you know could also be being in kind of you know you get into a pool it's not quite warm you get into a pool it's not quite warm you get into a pool it's not quite warm enough it could be that but you stay in enough it could be that but you stay in enough it could be that but you stay in longer but for 11 minutes it should be longer but for 11 minutes it should be longer but for 11 minutes it should be pretty uncomfortable you want to get out pretty uncomfortable you want to get out pretty uncomfortable you want to get out ideally if you ideally if you ideally if you why why why i should mention i should mention i should mention there's not much science around cold there's not much science around cold there's not much science around cold showers for the obvious reason that cold showers for the obvious reason that cold showers for the obvious reason that cold showers are hard to do in a laboratory showers are hard to do in a laboratory showers are hard to do in a laboratory because then you don't know are people because then you don't know are people because then you don't know are people under the is their head under are they under the is their head under are they under the is their head under are they facing it are they turning away most of facing it are they turning away most of facing it are they turning away most of these studies have been done with these studies have been done with these studies have been done with submersion but the other day when i was submersion but the other day when i was submersion but the other day when i was in boston i woke up and i thought i in boston i woke up and i thought i in boston i woke up and i thought i really want some cold exposure it was really want some cold exposure it was really want some cold exposure it was cold outside so i just walked around in cold outside so i just walked around in cold outside so i just walked around in a t-shirt i walked to to get some food a t-shirt i walked to to get some food a t-shirt i walked to to get some food um in short sleeves everyone looked at um in short sleeves everyone looked at um in short sleeves everyone looked at me like i was crazy and got 30 minutes me like i was crazy and got 30 minutes me like i was crazy and got 30 minutes of cold exposure just walking to the of cold exposure just walking to the of cold exposure just walking to the store and i ubered home because it's store and i ubered home because it's store and i ubered home because it's really cold the wind chill was pretty really cold the wind chill was pretty really cold the wind chill was pretty pretty bad pretty bad pretty bad so or pretty good i should say so i so or pretty good i should say so i so or pretty good i should say so i think you get that 11 minutes per week think you get that 11 minutes per week think you get that 11 minutes per week and that sets you up for this effect and and that sets you up for this effect and and that sets you up for this effect and it should be divided across multiple it should be divided across multiple it should be divided across multiple sessions but it could be monday tuesday
sessions but it could be monday tuesday sessions but it could be monday tuesday wednesday and then you have four days wednesday and then you have four days wednesday and then you have four days off it could be monday wednesday friday off it could be monday wednesday friday off it could be monday wednesday friday it doesn't really matter it doesn't really matter it doesn't really matter so don't try and do 11 minutes in one go so don't try and do 11 minutes in one go so don't try and do 11 minutes in one go in an ice bath probably not i mean not in an ice bath probably not i mean not in an ice bath probably not i mean not at first i mean some people can do that at first i mean some people can do that at first i mean some people can do that now there are other reasons to do cold now there are other reasons to do cold now there are other reasons to do cold exposure what happens when you get into exposure what happens when you get into exposure what happens when you get into cold couple things you vasoconstrict and cold couple things you vasoconstrict and cold couple things you vasoconstrict and there's a rebound vasodilation so you're there's a rebound vasodilation so you're there's a rebound vasodilation so you're getting better perfusion and blood flow getting better perfusion and blood flow getting better perfusion and blood flow the biggest effect is a big increase 2.5 the biggest effect is a big increase 2.5 the biggest effect is a big increase 2.5 x increase in dopamine that lasts for x increase in dopamine that lasts for x increase in dopamine that lasts for several hours several hours several hours you know it's a significant increase you you know it's a significant increase you you know it's a significant increase you feel mentally clear you feel alert feel mentally clear you feel alert feel mentally clear you feel alert it increases metabolism for the reason it increases metabolism for the reason it increases metabolism for the reason we discussed before and then there's the we discussed before and then there's the we discussed before and then there's the process of getting into this cold water process of getting into this cold water process of getting into this cold water when you didn't want to and that is when you didn't want to and that is when you didn't want to and that is overriding limbic friction that's that overriding limbic friction that's that overriding limbic friction that's that top down control so you build resilience top down control so you build resilience top down control so you build resilience and no surprise there are a lot of the and no surprise there are a lot of the and no surprise there are a lot of the screening tools for special operations screening tools for special operations screening tools for special operations and other screening tools involved and other screening tools involved and other screening tools involved forcing people to get for people forcing people to get for people forcing people to get for people deliberately forcing themselves i should deliberately forcing themselves i should deliberately forcing themselves i should say to get into cold bodies of water say to get into cold bodies of water say to get into cold bodies of water that are really uncomfortable but not that are really uncomfortable but not that are really uncomfortable but not dangerously cold
dangerously cold dangerously cold so so there are other effects too for instance there are other effects too for instance there are other effects too for instance if you want to enhance fat loss and if you want to enhance fat loss and if you want to enhance fat loss and lipolysis it does seem like activating lipolysis it does seem like activating lipolysis it does seem like activating shiver is key shiver is key shiver is key because when you shiver the muscles because when you shiver the muscles because when you shiver the muscles release a molecule called succinate release a molecule called succinate release a molecule called succinate succinate then goes and activates the succinate then goes and activates the succinate then goes and activates the brown fat so you get a further increase brown fat so you get a further increase brown fat so you get a further increase in metabolism in metabolism in metabolism and and and there's yet another oh and to activate there's yet another oh and to activate there's yet another oh and to activate shiver excuse me i stuttered why i said shiver excuse me i stuttered why i said shiver excuse me i stuttered why i said shiver it almost sound like i was shiver it almost sound like i was shiver it almost sound like i was shivering shivering shivering the one of the best things you can do is the one of the best things you can do is the one of the best things you can do is get into the cold get into the cold get into the cold source whatever it happens to be source whatever it happens to be source whatever it happens to be if you don't shiver while you're in if you don't shiver while you're in if you don't shiver while you're in there get out but don't dry off there get out but don't dry off there get out but don't dry off and just stand there you'll start to and just stand there you'll start to and just stand there you'll start to shiver pretty quickly as it starts to shiver pretty quickly as it starts to shiver pretty quickly as it starts to evaporate off you evaporate off you evaporate off you [Music]
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The 11-Minute Protocol
The research that put numbers to this effect came from a human trial published in Cell Reports Medicine, led by Susanna Søberg. The finding was precise: 11 minutes of deliberate cold exposure per week — distributed across two or three sessions of two to three minutes each — increased brown fat density in adult participants. To be clear, this was not an increase in body fat but an increase in mitochondrial density within the brown fat already present. The tissue grew more capable, not more abundant. The furnace, in other words, burned hotter and longer than it had before the protocol began.
The metabolic improvements extended well beyond brown fat itself. Participants in the Søberg study showed improvements in resting metabolism, more favorable blood lipid profiles, and better insulin management — three markers with direct relevance to long-term metabolic health and longevity. The cold stimulus, applied in modest weekly doses, moved these indicators in ways that diet and exercise often struggle to match on their own. Mental resilience also emerged as a documented secondary benefit. A single protocol, delivering broad systemic returns.
The human context matters more than it might first appear. Much of the cold exposure research circulating in wellness communities is drawn from animal models — particularly rodents — where the findings are promising but not always translatable to adult human physiology. The Søberg trial was conducted in humans, under controlled conditions, tracking measurable physiological outcomes before and after the protocol. That distinction is significant when evaluating whether a practice earns a place in your weekly rhythm. This one did, demonstrated through rigorous method.
Eleven minutes is a deceptively small commitment. It is less time than a typical warm shower, less time than a short podcast. Spread across a week into two or three brief sessions, it demands fewer than four minutes on any given session day — a threshold almost anyone can meet without restructuring their schedule. What the protocol requires is not volume. It requires genuine discomfort within those minutes, and the consistency to repeat the stimulus across enough weeks for adaptation to consolidate.
The protocol also reveals that benefits compound as adaptation deepens. As mitochondrial density increases over weeks of consistent practice, the body becomes more adept at managing cold temperatures during ordinary daily life — not just during deliberate sessions. Participants reported growing ease in cold environments and greater resilience — a downstream effect of the very tissue they had trained. Each session builds on the last; the body becomes both more capable and more at ease with each cycle of stimulus and recovery.
Eleven minutes per week is a threshold, not a ceiling. Those who want to pursue deeper adaptation can extend session duration, reduce water temperature, or increase weekly frequency — but the Søberg data suggests the baseline return on this modest investment is already substantial. The body is waiting to respond. It simply needs the signal, applied with enough regularity and discomfort to register as something worth adapting to.
How Cold, How Often, and Which Method
The most persistent misconception about deliberate cold exposure is that it requires specialized equipment or extreme conditions. It does not. A cold shower, an ice bath, a lake at dawn, an ocean swim — each of these qualifies. So does a winter walk in fewer layers than comfort would normally suggest, as the body's thermal response to cold air can produce many of the same adaptive signals. The method by which you get cold is far less important than the fact that you do.
Temperature is personal, and that is by design. What registers as uncomfortably cold for one person may feel perfectly manageable to another, depending on their baseline, their exposure history, and the current season. There is no universal number to target. The meaningful threshold is the one where every instinct tells you to remove yourself from the stimulus — and where the practice becomes staying anyway. That subjective discomfort is the signal the body needs; the specific degree is secondary.
Safety is the one non-negotiable parameter. The goal is cold that challenges you — not cold that overwhelms your body's capacity to respond. The practical standard is this: the temperature should feel uncomfortable enough that you want to exit, but controlled enough that you can slow your breathing, settle your attention, and remain for the full session. That boundary between productive discomfort and genuine danger is one you calibrate through experience, beginning conservatively and adjusting as tolerance and confidence build.
What's uncomfortable to you is not going to be uncomfortable to me.
Distributing sessions across the week matters more than many people expect. The Søberg protocol achieved its results through multiple short sessions spread over seven days — not from compressing 11 minutes into a single sitting. Monday, Wednesday, and Friday works well as a framework. Any similar pattern that prevents back-to-back sessions and preserves recovery time between them will serve the same purpose. What the body needs is repeated signaling over time, not a single extended episode that satisfies the week's quota in one go.
For those who find very cold water inaccessible, milder temperatures held for longer durations offer a valid alternative. Research has shown that participants submerging in water around 60 degrees Fahrenheit — not dramatically cold — for 45 minutes achieved meaningful metabolic results. The relationship between temperature and duration is adjustable: colder and shorter, or milder and longer, both pathways can reach the necessary thermal stress. The body does not require intensity; it requires sufficient discomfort sustained long enough to register as an adaptive signal.
The practical implication is that almost anyone can find a viable access point. Cold exposure is not the exclusive domain of ice bath enthusiasts or winter open-water swimmers. A cold shower turned to its lowest setting, held for two to three minutes, three times each week, is enough to begin the adaptation. The body does not require an elaborate protocol; it requires a genuine stimulus, applied with enough regularity to teach it something new. Begin where access allows, and let the adaptation earn the refinement over time.
What the Cold Does to You
The physiological response to cold immersion begins the moment the body registers the thermal drop. Blood vessels at the surface constrict — vasoconstriction — redirecting blood flow toward the core to protect vital organs and preserve core temperature. When you exit the cold, rebound vasodilation follows: vessels open again, and blood rushes back through the periphery with increased force, improving perfusion throughout the body. Recovery benefits from this enhanced circulation — nutrient delivery improves, metabolic waste clears more efficiently, and tissues that need replenishment receive it.
The dopamine effect is among the most striking outcomes of a deliberate cold session. Immersion produces a 2.5-fold increase in dopamine, and unlike the brief spikes associated with many pleasurable stimuli, this elevation sustains for several hours after the session ends. The result is the clarity and alertness that regular practitioners describe — a quality of focus and presence that arrives after the cold and persists through the morning or afternoon. Mood lifts, attention sharpens, and the hours following a session carry a different texture than those that preceded it.
There is also a dimension of mental training embedded in every session. Each time you override the instinct to exit the cold — each time you remain when every signal tells you to leave — you are exercising top-down limbic control. This is the practice of choosing to stay rather than reacting to the urge to flee, and that capacity for deliberate override does not stay contained within the cold plunge. Resilience built under thermal stress transfers into other contexts where physical or mental pressure must be managed. The cold is the training ground; what you build there extends well beyond it.
Shivering, often treated as a signal that a session has gone too long, is actually a mechanism worth deliberately inviting. When shivering muscles contract, they release a molecule called succinate; succinate then activates brown fat directly, producing a secondary surge in metabolic activity and energy output beyond what the cold stimulus alone generates. For those seeking to amplify fat metabolism, the shiver response is the pathway. Cold exposure primes the brown fat; shivering pushes that thermogenic activation further, creating a compounding metabolic effect within a single session.
Inducing the shiver response after a session requires only one deliberate choice: skip the towel. Allow water to evaporate from the skin — as it does, the body's surface temperature continues to fall, and shivering begins quickly. This post-immersion window, often overlooked in favor of warming down as fast as possible, extends the metabolic benefit of the session without any additional time in the cold. The body continues to work; you simply stay present for that final stage of the protocol.
The cumulative effect of consistent cold practice is a body better calibrated for vitality — physiologically and mentally. Brown fat burns hotter; dopamine sustains focus and elevates mood for hours; circulation delivers more efficiently; and resilience compounds session by session. Each of these benefits arrives within a commitment of 11 minutes each week. The practice asks very little in time, and a great deal in the willingness to remain present and still in genuine discomfort.
