Essentials: Increase Strength & Endurance with Cooling Protocols | Dr. Craig Heller

Andrew Huberman and Dr. Craig Heller explain why heat, not just lactic acid or willpower, is a primary limiter of muscular performance: a temperature-sensitive enzyme shuts off fuel to muscle mitochondria once muscle temperature exceeds about 39 degrees Celsius. Heller details the special arteriovenous shunts under the hairless skin of the palms, soles, and upper face that act as the body's true heat-loss portals. They debunk popular cooling myths, ice baths, neck and torso cooling, which can cause vasoconstriction and trick the brain's hypothalamic thermostat into a dangerous false sense of cooling. Heller shares lab results, including a 49ers tight end who tripled his dip volume in a month using palmar cooling, and an experiment that doubled treadmill endurance in the heat. The episode closes with practical, crude DIY protocols (frozen peas passed between the hands) and the caveat that cooling must be mild, not ice-cold, to avoid shutting down the very portals you want to exploit.

• A temperature-sensitive enzyme shuts off fuel to the mitochondria above ~39C, meaning muscle overheating is a direct cause of failing on your last rep.
  00:06:17
• Cooling the torso or neck can cause vasoconstriction and make core temperature rise while you feel great, a potentially dangerous illusion.
  00:11:00
• You can feel fine yet be dangerously hyperthermic; when you stop cooling, hot core blood floods the brain.
  00:12:00
• A San Francisco 49ers tight end (Greg Clark) doubled his total dips in days and tripled them within a month using palmar cooling between sets.
  00:21:47
• In a first treadmill experiment with ~18 off-the-street subjects, cooling doubled their uphill walking endurance in 40C heat.
  00:23:21
• Cooling the palms, soles, and face cools a hyperthermic person twice as fast as the medically recommended armpit, groin, and neck cold packs.
  00:29:33
• Cooling-driven gains are a true conditioning effect; you keep the strength and endurance improvements even when you later train without cooling.
  00:25:14

• Muscle metabolism and heat production can spike 50 to 60-fold during anaerobic activity, far faster than blood flow can carry the heat away.
  00:05:45
• The body's heat-loss portals sit under glabrous (hairless) skin: the palms, the soles of the feet, and the upper face above the beard line.
  00:13:32
• These special arteriovenous shunts evolved because furred mammals could only shed heat through their few hairless surfaces, like a rabbit's inner ears.
  00:14:34
• Blood cooled in the face returns through veins that pass through the skull and can reverse direction to actively cool the brain when you're overheated.
  00:17:39
• Gripping handlebars, a phone, or a barbell too tightly squeezes off the palm's heat-loss vessels and limits performance.
  00:16:06
• Gloves and socks impede heat loss; thin coverings on hands and feet help you stay cool and perform longer.
  00:16:37
• Effective cooling should feel merely cool, not ice-cold; ice water triggers reflexive vasoconstriction that seals heat inside the body.
  00:25:58
• The rate of heat loss follows an exponentially declining curve, so about 3 minutes captures most of the benefit.
  00:26:31
• People transitioning into heat stroke paradoxically vasoconstrict and stop sweating, which is why motivated athletes can push into deadly heat stroke during practice.
  00:12:31
• Taking a cool shower before a long run increases your body's capacity to absorb excess heat, delaying the point of overheating.
  00:03:39

Books, products and media the guest or host genuinely endorsed here — with the buy link.

Affiliate link — we may earn a commission at no extra cost to you.