Audit a URL →

Sign in Sign up free

Loading…

Weekly · Sunday Morning

Five longevity claims.
Worth your time.
Every Sunday.

Last Sunday

Rapamycin extends mouse lifespan 9–14%
NAD+ precursors reverse aging in humans
Blue-light glasses improve sleep quality
Walking 10 min after meals blunts glucose
Verdict change — caffeine half-life downgraded

5 audits·1 verdict change·0 affiliate links·Every Sunday

Joining 1,247 readers — founders, MDs, and longevity-obsessed people who fact-check their own health decisions.

Browse

Decisions Claims Content Creators

Product

Audit a URL Sunday roundup API (soon)Pricing

About

FAQ Methodology Editorial Standards Corrections Press & brand RSS feed

Legal

Terms of Service Privacy Policy DMCA

Finally, something serious in this space.
Because we actually read the papers.

© 2026 Whalespan. Independent, evidence-graded longevity.

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

Content›Video›AMA #7: Cold Exposure, Maxim…

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

Andrew Huberman22m · 2023-05-31

Claims Made

33

Claims Supported

22

Support Rate

67%

Support rate

22 of 33 claims supported

22 supported11 partial / not

Claims from this content

27

✓Well SupportedEase into deliberate cold exposure protocols gradually over a week to adapt to the shock of cold water.✓Well SupportedAdrenaline release from stressors like cold exposure or hyperventilation can help combat infections.✓Well SupportedDeliberate cold exposure can increase immune system markers when performed repeatedly over time.◐Partially SupportedIf feeling unwell or run down, engage in deliberate cold exposure but prioritize warming up thoroughly afterwards.Not Supported

More from Andrew Huberman

Andrew Huberman on Creatine

Huberman X thread: creatine and aging

Andrew Huberman on Morning Sunlight

Discussion

Native comments, Twitter mentions, and Reddit threads about this content — surfaced together so the conversation isn't fragmented across platforms.

M

Share your read of this content…

Posting publicly as you · linked to your social profiles

Sort by:

AV

A. Volkovreader

4h

Bookmarking — the dossier-vs-overview split is the right call. Most of the time I want overview; sometimes I want receipts.

NP

N. Park

2d

Would love a "what would change this verdict" RSS feed. Sign me up if it exists.

✕

If already experiencing a bacterial or viral infection, cyclic hyperventilation breathing or deliberate cold exposure may be detrimental.

◐Partially SupportedThe Wim Hof breathing pattern can counter endotoxin infection by increasing adrenaline and activating the spleen.

◐Partially SupportedFever is an adaptive mechanism that helps the body by making it too hot for pathogens to survive.

◐Partially SupportedSickness behavior involves multiple pathways that signal the body to avoid light, reduce activity, and increase temperature to combat infection.

◐Partially SupportedCold, dry air appears to increase susceptibility to viral and bacterial infections.

◐Partially SupportedWim Hof breathing involves hyperventilation, exhalation, and breath holds, and liberates adrenaline to counter infection and stress.

◐Partially SupportedEpinephrine and norepinephrine, released in response to cold water exposure and deliberate hyperventilation, can have short-term pro-immune effects by triggering immune cell activation.

✓Well SupportedCold exposure triggers an immune response as the body perceives a threat of death, activating immune modulators.

✕Not SupportedChronic elevation of norepinephrine and epinephrine, especially late in the day, can reduce the number and efficiency of immune cells.

◐Partially SupportedNasal breathing is generally preferable to mouth breathing during low-intensity activities as it may reduce the risk of infection entry.

✕Not SupportedWhen feeling unwell or run down, avoid stressful activities like cold exposure, heat challenges, or intense exercise, and focus on rest and light movement.

◐Partially SupportedMore humid, warm environments make the mucosal lining and upper respiratory area more robust against bacterial and viral infections.

◐Partially SupportedExcessive increases in norepinephrine and epinephrine can suppress the immune system.

◐Partially SupportedMouth breathing in cold, dry environments can dry nasal passages and increase susceptibility to infections.

?Limited ResearchThe increase in immune cells and markers from cold exposure may not translate to significant resistance against specific viral or bacterial infections.

◐Partially SupportedCold exposure for one to ten minutes followed by warming up is unlikely to directly cause illness.

◐Partially SupportedResting when sick is beneficial because it allows the body's resources to be fully devoted to recovery from infection.

◐Partially SupportedCold exposure can boost or suppress the immune system depending on the conditions.

◐Partially SupportedIf feeling slightly unwell, taking a hot shower and sleeping is advised, though some may choose cold exposure followed by warming.

◐Partially SupportedTypical deliberate cold exposure protocols involve temperatures around 4-7°C for 1 to 10 minutes.

◐Partially SupportedDeliberate cold exposure does not induce infection if water is clean and skin is intact.

◐Partially SupportedDeliberate cold exposure in 14°C water for one hour did not significantly change immune system function after a single exposure.

◐Partially SupportedA study exposing individuals to 14°C (57.2°F) water for one hour showed relevance to immune system responses in cold-adapted humans.