Andrew Huberman: Professor of neurobiology and ophthalmology at Stanford School of Medicine and host of the Huberman Lab Podcast, translating science into actionable tools for everyday life.
What this episode covers
This solo Huberman Lab episode opens a series on optimizing physical performance and argues that temperature, not supplements, is the most powerful lever for exercise output and recovery. Huberman explains the body's three heat-exchange compartments and the special glabrous-skin regions (palms, soles, face) whose AVA vasculature can rapidly cool or heat the core. Drawing on the work of Stanford colleague Craig Heller, he describes how palmar cooling let subjects go from roughly 100 to 600 pull-ups and outperform a testosterone group on bench press. He then covers how cooling these portals (without causing vasoconstriction) speeds recovery, and warns that ice baths, caffeine, NSAIDs, and stimulant pre-workouts can either blunt muscle growth or raise body heat and impair performance.
Recommended on this episode
Thermoregulation in Human Performance: Physiological and Biological Aspects
Effie Marino
“The one that I've been relying on is called Thermoregulation in Human Performance, Physiological and Biological Aspects by Effie Marino”— Andrew Huberman
Also referenced (named, not recommended)
testosterone cypionate
testosterone cypionate
“the antibiotic steroid was testosterone cypionate which is essentially testosterone, and indeed the testosterone cypionate, the steroid group improved at a rate of about 1% per week”— Andrew Huberman
Tylenol
Johnson & Johnson
“non-steroid anti-inflammatories so things like Tylenol and Advil and other trade names and Neproxin sodium things of that sort, almost all of those drop body temperature”— Andrew Huberman
Advil
Pfizer
“non-steroid anti-inflammatories so things like Tylenol and Advil and other trade names and Neproxin sodium things of that sort, almost all of those drop body temperature”— Andrew Huberman
Big reveals from this episode
- A 49ers athlete tripled his dip output within a week using proper palmar cooling, then kept the gains even without cooling.
- Subjects went from about 100 pull-ups to 180 with palmar cooling, and up to 600 over several weeks of training.
- In a bench-press study the cooling group beat a control group taking testosterone cypionate, which improved only about 1% per week.
- The body has three heat-exchange compartments, and the palms, soles, and face are dramatically better at dumping or absorbing heat.
- Immersing the body in cold after training can block mTOR and short-circuit the muscle-growth (hypertrophy) response.
- Huberman saw a 60% increase in his own dips just by cooling his hands and feet in slightly cool water.
- The temperature-sensitive enzyme pyruvate kinase is the rate-limiting step that makes overheated muscles stop contracting.
Worth remembering
- Huberman argues temperature is even more important than sleep for performance because it dictates how well and when you sleep.
- If muscle temperature reaches around 39-40 degrees Celsius, ATP function drops and you can no longer generate contractions.
- The palms, soles, and face contain glabrous skin with AVAs (arterio-venous anastomoses) that bypass capillaries to move heat fast.
- Heat raises heart rate independently of effort via cardiac drift, and the brain's heat-plus-effort computation triggers you to quit.
- To rewarm a hypothermic person, warming the palms, soles, and face is more effective than pressing a warm chest against them.
- The cooling water should be only slightly below body temperature, not ice-cold, or it causes vasoconstriction and blocks heat transfer.
- Athletes who cool their core, neck, or head between rounds are using a far less efficient recovery method than cooling glabrous skin.
- Whether caffeine helps or hurts depends on adaptation: in habitual users it causes vasodilation, in non-users it constricts vessels.
- Alcohol is a vasodilator that lowers body temperature, so a post-run beer can actually aid heat dumping for some athletes.