Using Deliberate Cold Exposure for Health and Performance

In this episode of the Huberman Lab Podcast, Dr. Andrew Huberman goes over the following topics:

• Deliberate cold exposure and health: precautions
• Utilizing moderate exercise and cognitive work as strategies
• The agreement between the brain and body
• Exploring circadian rhythms and body temperature
• Methods for rapidly lowering core body temperature and treating glabrous skin
• Psychological impacts of exposure to cold
• Physiological implications of cold exposure
• Determining the ideal cold temperature
• Comparing cold showers with cold water immersion
• Establishing protocols for cold exposure
• Optimal mental approaches during cold exposure
• Incorporating movement during cold exposure
• Determining the best frequency for cold exposure
• Leveraging cold exposure for dopamine regulation, mood enhancement, and improved focus
• Understanding the impact of cold exposure on metabolism and brown fat activation
• Using caffeine in conjunction with cold exposure to influence dopamine levels
• Tools and strategies for enhancing metabolism through cold exposure, such as the Søberg principle and inducing shivering
• Exploring the role of norepinephrine in fat cells during cold exposure
• The correlation between cold exposure, physical performance, and inflammation
• Managing hyperthermia and cooling glabrous skin
• Utilizing Palmar cooling techniques to enhance endurance
• Cold exposure targeting the groin area to boost testosterone levels
• Determining the optimal timing for daily cold exposure

Dr. Huberman’s episode lays out a practical protocol for cold exposure and ties it to several outcomes, from mood and focus to metabolism and recovery. The sections below separate what the research supports from what is still a hypothesis, and explain the safety limits, which matter more here than in most wellness topics.

What happens in the body

Cold is a real physiological stressor. In a controlled study of young men, one-hour head-out immersion in 14 degree Celsius water raised metabolic rate by about 350%, and plasma noradrenaline by about 530% and dopamine by about 250%. Blood pressure and heart rate rose modestly, and cortisol did not increase. The authors concluded that the responses to cold are mainly due to increased activity of the sympathetic nervous system (Šrámek et al., 2000).

This is the basis for the claim that cold exposure raises dopamine and improves mood and focus. The hormone response is real and large. What is missing is good evidence that regularly repeating it improves mood, focus or motivation: that study measured blood chemistry in a small group, not mood or attention. Treat the mood claim as plausible and untested. People who enjoy cold showers often report feeling alert afterward, which is a fair reason to use them, but it is not proof of a treatment effect.

Brown fat and metabolism

Brown adipose tissue burns energy to make heat. A study of experienced winter swimmers who dipped in cold water two to three times per week found a stronger increase in cold-induced thermogenesis and skin temperature over the collarbone than in non-swimmers, which suggests the body adapts to repeated cold. The authors proposed winter swimming as a potential strategy for increasing energy expenditure (Søberg et al., 2021). This was a small comparison of existing swimmers and controls, so it cannot show that taking up cold exposure causes fat loss. We did not find trials showing cold exposure produces meaningful weight loss on its own.

Illness and everyday use

In a randomized trial of 3,018 adults, those assigned to finish their showers with 30, 60 or 90 seconds of cold water for 30 days reported 29% fewer sick days away from work than the control group. The number of illness days did not differ, so people were not actually less sick, and the outcome was self-reported (Buijze et al., 2016). No related serious adverse events were reported in that trial, which excluded people with severe medical conditions. A cold finish to a shower is the lowest-risk version of the practice, and it is where most people should begin.

Performance and recovery

Cold-water immersion after hard exercise is popular. A Cochrane review of 17 small, low-quality trials (366 participants) found some evidence that it reduces delayed onset muscle soreness compared with rest (Bleakley et al., 2012). But there is a trade-off for people trying to build muscle. In a 12-week trial of 21 men, those who sat in cold water after each strength session gained less muscle mass and strength than those who did active recovery (Roberts et al., 2015). If strength or size is your goal, it is sensible to keep cold exposure away from the hours after lifting, which fits with the advice in our article on resistance training after 40.

The episode also covers palmar (hand) cooling to improve endurance. The best-known study used a specialized device that combined a cooled surface with reduced pressure on the hand, and the benefit was measured while walking uphill in a 40 degree Celsius room (Grahn et al., 2005). That is a long way from cold packs or a bucket of water, and we did not find controlled evidence for everyday versions. The claim that cooling the groin raises testosterone is one we could not source to any controlled human study, so we would not rely on it.

Cold and your daily rhythm

Body temperature follows a daily cycle tied to sleep and wakefulness, and Dr. Huberman discusses timing cold exposure around it. If you use cold for alertness, earlier in the day is the logical choice, and morning light is a natural companion; see morning sunlight and circadian health. Cold close to bedtime may leave you more alert than you want to be, which is an inference from how the response works rather than a tested finding.

Safety first

The risks of cold exposure are the main reason to be careful, because the main danger comes in the first minute.

• Cold shock. Sudden immersion in cold water causes an involuntary gasp, rapid breathing, and a surge in heart rate and blood pressure. Researchers report that cold water submersion can induce a high incidence of cardiac arrhythmias in healthy volunteers, and propose that a conflict between the body’s cold shock and diving responses may explain some sudden deaths previously attributed to drowning (Shattock & Tipton, 2012).
• Open water. A narrative review concluded that cold water swimming appears to bring health benefits when practiced by experienced, healthy people in a regular, graded way, but that unfamiliar people face a risk of death from the cold shock response, a progressive loss of swimming efficiency, or hypothermia (Knechtle et al., 2020). Never swim in cold open water alone, enter slowly, and stay close to the shore or exit.
• Heart and blood pressure. If you have heart disease, an arrhythmia, uncontrolled high blood pressure or have had a stroke, speak to a clinician before trying cold water immersion. The cold shock is a cardiovascular stress.
• Raynaud’s. Cold is the main trigger for Raynaud’s, where fingers or toes turn white, blue or red and may be painful. See a GP if symptoms are severe, affect one side only, or begin after age 30 (NHS).
• Progress gradually. Begin with 15 to 30 seconds of cold at the end of a warm shower, keep your breathing slow, and skip it when you feel faint or unwell.

The honest takeaway

Cold exposure produces large, reliable physiological responses, and a cold finish to a shower seems safe and may be pleasant for healthy adults. Beyond that, the evidence is thinner than the enthusiasm: the dopamine and mood benefit has not been tested, metabolic effects come from small studies of experienced swimmers, and cold may blunt gains from strength training. Take the episode as an introduction to a tool with real effects and real risks, start with showers, and keep cold water immersion for after you have checked your health and arranged company.

References

• Šrámek, P., et al. (2000). Human physiological responses to immersion into water of different temperatures. European Journal of Applied Physiology, 81(5), 436–442. PubMed
• Søberg, S., et al. (2021). Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men. Cell Reports Medicine, 2(10), 100408. PubMed
• Buijze, G. A., et al. (2016). The effect of cold showering on health and work: a randomized controlled trial. PLoS ONE, 11(9), e0161749. PubMed
• Bleakley, C., et al. (2012). Cold-water immersion (cryotherapy) for preventing and treating muscle soreness after exercise. Cochrane Database of Systematic Reviews, (2), CD008262. PubMed
• Roberts, L. A., et al. (2015). Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. The Journal of Physiology, 593(18), 4285–4301. PubMed
• Grahn, D. A., Cao, V. H., & Heller, H. C. (2005). Heat extraction through the palm of one hand improves aerobic exercise endurance in a hot environment. Journal of Applied Physiology, 99(3), 972–978. PubMed
• Shattock, M. J., & Tipton, M. J. (2012). ‘Autonomic conflict’: a different way to die during cold water immersion? The Journal of Physiology, 590(14), 3219–3230. PubMed
• Knechtle, B., et al. (2020). Cold water swimming: benefits and risks, a narrative review. International Journal of Environmental Research and Public Health, 17(23), 8984. PubMed
• NHS. Raynaud’s: cold as a trigger, symptoms and when to see a GP. NHS

Related reading

• Resistance Training After 40: Why Strength Becomes the Priority
• Morning Sunlight and Circadian Health: A Simple Daily Anchor
• Zone 2 Cardio Without the Gadget Confusion: A Pace You Can Repeat

This article is for general educational purposes and is not a substitute for personalized medical advice. Anyone with a heart condition, high blood pressure or circulation problems should speak with a clinician before trying cold exposure.