← Huberman Lab

AMA #7: Cold Exposure, Maximizing REM Sleep & My Next Scientific Studies

May 31, 2023 22m 20s 9 insights
Welcome to a preview of the seventh Ask Me Anything (AMA) episode, part of the Huberman Lab Premium subscription. The Huberman Lab Premium subscription was launched for two main reasons. First, it was launched in order to raise support for the standard Huberman Lab podcast channel — which will continue to come out every Monday at zero-cost. Second, it was launched as a means to raise funds for important scientific research. A significant portion of proceeds from the Huberman Lab Premium subscription will fund human research (not animal models) selected by Dr. Huberman, with a dollar-for-dollar match from the Tiny Foundation. Subscribe to Huberman Lab Premium at https://hubermanlab.com/premium.
Actionable Insights

1. Avoid Cold Exposure When Sick

If you are feeling malaise, tired, or significantly unwell due to a cold, flu, or bacterial infection, avoid deliberate cold exposure, strenuous exercise, or heat challenges. Your body needs to conserve resources for healing, and stress from these activities can hinder recovery.

2. Rest When Unwell

When feeling sick, prioritize rest and avoid pushing yourself, as your body’s natural ‘sickness circuits’ are designed to encourage healing. This allows your body to devote all resources to combating the infection.

3. Prioritize Nasal Breathing

Consistently breathe through your nose, unless engaged in strenuous exercise or talking, because it acts as a primary barrier against infections entering through the mouth. Nasal breathing is generally better than mouth breathing for overall health.

4. Gradual Cold Exposure & Warm-up

If new to deliberate cold exposure, start with shorter durations (e.g., 1-3 minutes) and gradually increase, never jumping straight to long exposures like 10 minutes. Always warm up thoroughly afterwards by getting clothed, taking a hot shower/sauna, or basking in the sun to prevent prolonged cold exposure.

5. Warmth for Mild Sickness

If experiencing a mild sniffle or feeling a little run down, opt for warmer hot baths, hot showers, or a non-stressfully hot sauna instead of cold exposure. For mild unwellness, taking a hot shower and going to sleep is often the best advice.

6. Regular Cold Exposure Boosts Immunity

Engage in deliberate cold exposure repeatedly, such as three times per week over six weeks, to potentially increase immune system markers like T lymphocytes and IL-6. This effect is mediated by the release of epinephrine and norepinephrine, which can be pro-immune.

7. Cyclic Hyperventilation for Immunity

Practice cyclic hyperventilation (e.g., Wim Hof breathing, inhaling through the nose and exhaling through the mouth repeatedly 25 times or so) to release norepinephrine and epinephrine. This can activate immune cells and potentially reduce the symptomatic response to infections.

8. Avoid Chronic Adrenaline Spikes

Be mindful that chronically elevated levels of norepinephrine and epinephrine, especially late in the day and sustained over many days, can reduce the number and efficiency of immune cells. This suggests balancing stress-inducing protocols with adequate recovery.

9. Protect Mucosal Lining

Be aware that spending time in cold, dry environments, particularly with mouth breathing, can thin and weaken the mucosal lining of your nose and mouth. This makes you more susceptible to viral and bacterial infections, so protect these areas.