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The Science & Health Benefits of Deliberate Heat Exposure

Episode 69 Apr 25, 2022 1h 50m 19 insights
I describe the mechanisms by which deliberate heat exposure impacts body temperature, metabolism, heart health, hormone production, exercise recovery, cognition, mood, and longevity. I detail specific protocols for deliberate heat exposure, including exposure times, temperature ranges to consider, time of day, and delivery mechanisms (sauna vs. hot bath vs. open air heat, etc.) in order to achieve different specific outcomes, including dramatic growth hormone releases, or reduction in cortisol levels. I also discuss the ability of locally applied heat to heal or otherwise improve various bodily tissues and new data on how local application of heat may induce the conversion of metabolically sluggish white fat to metabolically robust beige fat. For the full show notes, visit hubermanlab.com.
Actionable Insights

1. General Sauna Protocol for Longevity

Engage in sauna sessions 2-7 times per week, for 5-20 minutes each, at temperatures between 80-100°C (176-212°F). This practice is associated with a significant reduction in cardiovascular mortality and improved overall longevity.

2. Enhance Mood with Deliberate Heat

Expose yourself to deliberately hot, uncomfortable but safe environments (like a sauna). This short-term discomfort activates the dynorphin system, which subsequently increases the efficiency of feel-good endorphin pathways, improving baseline mood and capacity for joy.

3. Boost DNA Repair & Longevity (FOXO3)

Use sauna 2-7 times per week at 80-100°C (176-212°F) to upregulate FOXO3. This molecule promotes DNA repair and the clearance of senescent cells, which is crucial for maintaining cognition and overall health.

4. Cardiovascular Workout Through Heat

Sitting in a hot environment like a sauna causes your heart rate to increase (100-150 bpm), blood flow to increase, and vasculature to dilate. This provides a cardiovascular workout without the joint loading of physical exercise, improving heart health.

5. Optimize Metabolism with Heat & Cold

Combine 11 minutes total per week of uncomfortably cold but safe cold exposure (divided across 2+ sessions) with 57+ minutes per week of uncomfortably hot but safe heat exposure (divided across 3+ sessions). This protocol has been shown to improve metabolism and increase brown fat stores.

6. Reduce Cortisol with Heat & Cold Contrast

Perform 12-minute sauna sessions (around 90°C/194°F) followed by a 6-minute cool-down in 10°C/50°F water (or a cool/cold shower). This specific protocol has been shown to significantly decrease cortisol output, helping to manage stress.

7. Maximize Growth Hormone Release

To achieve a 16-fold increase in growth hormone, perform 4 sessions of 30 minutes each in an 80°C (176°F) sauna, with cooling periods in between. Limit this intense protocol to no more than once a week (or every 10 days) to avoid heat adaptation and do it fasted or 2-3 hours after eating, as elevated blood glucose/insulin blunt growth hormone release.

8. Optimal Sauna Timing for Sleep

Do heat exposure (sauna) in the later half of the day or just before sleep. The post-sauna cooling effect helps your body temperature drop, which aids in falling asleep and maintaining sleep.

9. Post-Sauna Hydration

Drink at least 16 ounces of water for every 10 minutes spent in the sauna, potentially with electrolytes. This is crucial to replace water and electrolytes lost through sweating and maintain cellular function.

10. DIY Heat Exposure Methods

If a sauna is unavailable, achieve similar benefits by taking hot baths/tubs, using hot showers, or exercising while wearing warm clothing (e.g., hoodie, wool hat, plastic suit). The goal is to properly heat your shell and core body temperature.

11. Heat Exposure Safety Guidelines

Always approach heating tools cautiously, starting with lower temperatures and durations, and gradually increasing. Consult your doctor if pregnant, nursing, or sensitive to heat, as hyperthermia can cause neuron damage.

12. Rapid Core Cooling Technique

To quickly cool the core body temperature (e.g., during hyperthermia), apply cool (not freezing) objects or fluids to glabrous skin surfaces: palms of hands, bottoms of feet, and the upper half of the face. This method is more efficient than cooling other body parts due to specific vascular structures.

13. Rapid Core Heating Technique

To quickly warm the core body temperature (e.g., during hypothermia), apply warm (not burning) objects or fluids to glabrous skin surfaces: palms of hands, bottoms of feet, and the upper half of the face. This leverages specific vascular structures for efficient heat transfer.

14. Fever Management Approach

Avoid reducing fever with medication unless it’s dangerously high (e.g., above 103-104°F), as fever is a natural protective mechanism against pathogens. If fever becomes dangerously high, seek medical attention and use rapid core cooling methods to prevent hyperthermia.

15. Local Heat for Fat Conversion (Experimental)

To potentially convert white fat to beige fat and increase metabolism, apply local heat (41°C/105.8°F) to areas like the supraclavicular fat deposits for 20 minutes, three days per week (e.g., M/W/F) for five weeks. Caution: This is a new, experimental finding; do not damage skin.

16. Utilize Momentus Supplements

Access high-quality supplements and specific dosages supported by scientific research at livemomentus.com/Huberman. Combine these with behavioral protocols discussed on the podcast for maximum benefit.

17. Take Athletic Greens Daily

Take Athletic Greens once or twice a day to cover basic nutritional needs, address deficiencies, and support microbiome health with probiotics. Claim a special offer at athleticgreens.com/Huberman for five free travel packs and a year’s supply of vitamin D3K2.

18. Ensure Electrolyte Hydration

Dissolve one packet of Element in 16-32 ounces of water first thing in the morning and during physical exercise. This ensures adequate hydration and essential electrolytes (sodium, magnesium, potassium) for optimal brain and body function.

19. Practice Meditation with Waking Up

Use the Waking Up app for meditation programs, mindfulness training, yoga nidra, or non-sleep deep rest (NSDR) protocols. Even short 10-minute sessions can greatly restore cognitive and physical energy.