The claim
“Eleven minutes of cold a week is the ideal dose.”
Hot air. A 2021 paper added up the cold-water habits that seven Danish winter swimmers reported and got 11 minutes a week. The study never assigned or compared a dose, and its lab cold came from water-perfused blankets.
Updated Sep 24, 2026 · 1 study reviewed
Nothing solid supports it, or the evidence points the other way.
People say it in places like these
Huberman Lab newsletter
Aim for 11 minutes of cold a week in total and treat that as the minimum.
See an example ↗Susanna Søberg on Huberman Lab
Eleven minutes a week in total is a low threshold people can aim for.
See an example ↗Polar Monkeys
The research-supported target for most goals is about 11 minutes of cold a week.
The research found this
The figure comes from a 2021 study in Cell Reports Medicine by Susanna Søberg and colleagues in Denmark. They compared young men who swam in cold water through the winter with men matched on age, sex, BMI and aerobic fitness who used neither cold water nor sauna.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗ Eight swimmers were recruited. One was dropped because his scan showed no cold-activated brown fat, so seven remained.
The 11 minutes sits in Table 1, which lists what the swimmers said they did. On average they swam 2.6 times a week and went into the water 2.6 times per visit. Each immersion averaged 1.4 minutes. The standard deviation of 2.6 minutes was bigger than the average itself, so habits varied a lot from man to man. The table adds it all up to 11 minutes of cold water and 57 minutes of sauna heat a week.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗
The lab work tested how the two groups handled cold. The men lay under two water-perfused blankets, and the water was stepped down according to how cold each man felt until he was just short of shivering.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗ During 30 minutes of that cooling the swimmers burned energy at a rate equal to 3,044 kcal a day, against 2,560 for the controls. At a comfortable temperature the groups didn't differ.
The swimmers also differed from the controls in body fat and glucose handling. Their tissue fat averaged 12.0% against 18.2% in the controls, and their glucose tolerance was better. The authors note that men whose bodies handle cold in a particular way may be the ones who take up winter swimming.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗
The dial reads 89°H for four reasons
How the reading adds up
22 + 18 + 25 + 24 = 89°H
EvidenceWhat kind of evidence exists in people?
22/25No study has tested 11 minutes or any other weekly total against a health outcome. The figure is a line in Table 1 of a cross-sectional study that compared seven winter swimmers with eight men who used neither cold water nor sauna.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗
ConsistencyHas the finding held up?
18/25The number rests on one small group's habits. Trials that compared doses found shorter ones worked as well: cold-shower finishes of 30 to 90 seconds cut self-reported days off sick by the same amount, and 5 minutes in cold sea water lifted mood as much as 20.Source 2 · Randomized trialThe Effect of Cold Showering on Health and Work: A Randomized Controlled TrialBuijze GA, Sierevelt IN, van der Heijden BCJM, et al.. PLOS ONE, 2016.Read the paper ↗PubMed ↗Source 3 · Randomized trialImproved Mood Following Cold‐Water Immersion: A Comparison of Differing Exposure DurationsKelly JS, Davidson N, Delaney JP. Lifestyle Medicine, 2026.Read the paper ↗
MagnitudeDoes the claim match the size of the effect?
25/25The claim describes an ideal that nobody measured. The swimmers were compared only with men who took no cold dips or saunas at all, so the study can't rank 11 minutes against any other amount.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗
DoseDoes the studied protocol match how people use it?
24/25The study never gave anyone 11 minutes of cold. Its lab cold came from water-perfused blankets, and the only immersion in the protocol was one hand in 4°C water for 3 minutes.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗
The claim drifts from the data here
A newsletter turned the table entry into a target. The Huberman Lab newsletter of 1 May 2022 recommended about 11 minutes of deliberate cold a week and credited a recent study without naming it.Source 4 · PodcastThe Science & Use of Cold Exposure for Health & PerformanceHuberman Lab. Huberman Lab Neural Network newsletter, 2022.Read the page ↗ The paper presents the figure as what seven swimmers reported doing and never tests it.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗
The swimmers' routine also included 57 minutes of sauna a week. The paper speculates that heat acclimation from regular sauna use might explain the swimmers' lower core temperature and their missing brown fat activity at a comfortable temperature.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗ The newsletter's rule about ending on cold has no test behind it either.
Put it to use
Pick an amount of cold you'll keep up and skip the stopwatch. In trials that compared doses, 30 seconds of cold at the end of a shower cut days off sick as much as 90 seconds did, and 5 minutes in the sea lifted mood as much as 20.Source 2 · Randomized trialThe Effect of Cold Showering on Health and Work: A Randomized Controlled TrialBuijze GA, Sierevelt IN, van der Heijden BCJM, et al.. PLOS ONE, 2016.Read the paper ↗PubMed ↗Source 3 · Randomized trialImproved Mood Following Cold‐Water Immersion: A Comparison of Differing Exposure DurationsKelly JS, Davidson N, Delaney JP. Lifestyle Medicine, 2026.Read the paper ↗
From our sister magazine
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People also ask
Where does the 11 minutes of cold a week come from?
It comes from Table 1 of a 2021 Danish study. The table adds up the self-reported habits of seven young winter swimmers to 11 minutes of cold water and 57 minutes of sauna a week, and the study never tested that amount against any other.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗
How many minutes of cold exposure a week do you need?
No study has worked that out. Trials that compared session lengths found short sessions did as well as long ones for sick days and for mood.Source 2 · Randomized trialThe Effect of Cold Showering on Health and Work: A Randomized Controlled TrialBuijze GA, Sierevelt IN, van der Heijden BCJM, et al.. PLOS ONE, 2016.Read the paper ↗PubMed ↗Source 3 · Randomized trialImproved Mood Following Cold‐Water Immersion: A Comparison of Differing Exposure DurationsKelly JS, Davidson N, Delaney JP. Lifestyle Medicine, 2026.Read the paper ↗
Did the Søberg study use cold plunges?
Its lab tests cooled the men with water-perfused blankets to just short of shivering, and the only immersion was one hand held in 4°C water for 3 minutes. The winter swimming happened in the men's own lives, and the paper records it as reported habits.Source 1 · Cross-sectional studyAltered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming menSøberg S, Löfgren J, Philipsen FE, et al.. Cell Reports Medicine, 2021.Read the paper ↗PubMed ↗
Check these claims next
92°H
Hot air
“End your sauna session on cold to burn more fat.”
No human study has compared finishing a sauna session on cold with finishing it on heat for fat burning or any other outcome. The rule carries Susanna Søberg's name, and her 2021 paper never mentions it.
72°H
Stretched
“Cold plunges burn fat by switching on brown fat.”
Cold does switch on brown fat in people. The one controlled study that measured fat used two hours of 17°C air a day for six weeks and took off 0.7 kg of fat, and nobody has measured fat loss from plunges.
74°H
Stretched
“A cold plunge raises your dopamine by 250%.”
The 250% figure is plasma dopamine after a full hour in 14°C water, and the same lab found no significant dopamine rise when it ran that hour four years earlier. Dopamine in the blood comes mostly from nerves and the gut, and it barely reaches the brain.
We cited these sources
- 01Søberg S, Löfgren J, Philipsen FE, Jensen M, Hansen AE, Ahrens E, et al.. Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men. Cell Reports Medicine. 2021;2(10):100408. doi:10.1016/j.xcrm.2021.100408 PMID 34755128
- 02Buijze GA, Sierevelt IN, van der Heijden BCJM, Dijkgraaf MG, Frings-Dresen MHW. The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial. PLOS ONE. 2016;11(9):e0161749. doi:10.1371/journal.pone.0161749 PMID 27631616
- 03Kelly JS, Davidson N, Delaney JP. Improved Mood Following Cold‐Water Immersion: A Comparison of Differing Exposure Durations. Lifestyle Medicine. 2026;7(2):e70048. doi:10.1002/lim2.70048
- 04Huberman Lab. The Science & Use of Cold Exposure for Health & Performance. Huberman Lab Neural Network newsletter. 2022. Accessed Sep 24, 2026.