Supercharge Exercise Performance & Recovery with Cooling

High-Level Overview

In this solo episode, which opens a series on physical performance and skill learning, Andrew Huberman argues that temperature is the single most powerful and most overlooked lever for exercise performance and recovery. Muscles simply stop working when they get too hot, and the brain shuts down effort before the body overheats. The good news is that humans have three special surfaces, the palms, the soles of the feet and the face, that can move heat out of the body far faster than anywhere else. Drawing on research from his Stanford colleague Craig Heller, Huberman describes how cooling the palms the right way allowed people to double, triple and even multiply their pull-up, dip and bench press volume, and to run longer, while also protecting them from dangerous overheating.

The tone is enthusiastic and teaching-focused. Huberman explains the mechanism first, from sweating and goosebumps to a heat-sensitive muscle enzyme, then gives practical, low-cost protocols. He closes by questioning common habits such as ice baths after training, stimulant pre-workouts and anti-inflammatory drugs.

The Discussion Explores:

• A clarified learning protocol: calm focus while learning, an adrenaline spike afterward, then rest and sleep.
• How the body regulates temperature: vasoconstriction, vasodilation, sweating, goosebumps and why overheating is so dangerous.
• Why heat shuts down performance: a heat-sensitive enzyme in muscle and a brain reflex that makes us quit.
• The three cooling portals: palms, soles and face, and the special blood vessels (AVAs) that make them work.
• Craig Heller's cooling studies: dramatic gains in pull-ups, dips, bench press and endurance.
• Heat, willpower and cardiac drift: why rising temperature makes us stop sooner.
• Cooling for recovery: why cooling the right surfaces beats cold showers and ice baths after training.
• Stimulants, alcohol and NSAIDs: how common substances change body temperature and performance.

Deep Dive into Main Ideas

Clarifying the Adrenaline Learning Protocol

Before the main topic, Huberman clears up confusion from his previous episode on adrenaline and learning. His four-step protocol is to be calm and focused while learning a new cognitive or motor skill, then create a spike of adrenaline immediately afterward (for example with cold or breathing), then take a roughly 20-minute non-sleep deep rest (NSDR) session or shallow nap, and finally get good sleep that night and the next. He says many people get this backward, using too much caffeine, nootropics or even recreational Adderall to feel intensely alert during learning, when the physiology suggests the adrenaline spike belongs at the end.

Why Temperature Matters So Much

Huberman lists the many factors that affect performance, from sleep and hydration to supplements, breathing and mindset, but argues that a few have outsized effects. "Believe it or not, temperature is the most powerful variable for improving physical performance and for recovery", he says, even ranking it above sleep because temperature itself shapes how well we sleep and recover. He focuses mainly on cold, not as ice packs on sore muscles, but through thermal physiology. The body strongly defends a narrow temperature range. Overheating can kill neurons that don't come back and changes the shape of enzymes so cells stop working, like a car losing two wheels. We have more room to tolerate cold than heat, though both extremes can be deadly.

When we get cold, blood vessels constrict and blood moves toward the core to protect vital organs, and tiny nerve fibers raise body hair into goosebumps, a leftover from when fur trapped a layer of warm air. When we get hot, blood vessels dilate, more blood flows to the limbs, and we sweat. Sweat only cools us if it can evaporate, which is why humid days feel so much hotter. Dogs pant and camels spit to dump heat.

Heat Stops Muscles and Makes Us Quit

The key fact is that muscles need ATP to contract, and the range of temperatures where this works is narrow. Somewhere around 39 or 40 degrees Celsius, contraction drops off, and muscles can reach that temperature locally very fast. A heat-sensitive enzyme called pyruvate kinase is a rate-limiting step. As Huberman puts it, "Put simply, if you get too hot, you stop exercising." Keeping temperature in range lets you do more sets, more reps and run further.

He gives sobering examples of overheating. Stimulant-type substances such as ephedrine and clenbuterol raise body temperature to burn fat, and athletes died from overheating in practice, which led to clenbuterol being banned. He believes dehydration and overheating may contribute to deaths in combat sports alongside head trauma. His own college thesis studied how MDMA raises body temperature, showing that drugs can stop people from noticing they are too hot. Normally, the main protective behavior is simply to stop, a subconscious reflex. He recalls a runner in the 1984 Olympic women's marathon who became disoriented entering the stadium because she was dangerously overheated.

The Three Cooling Portals and AVAs

The body has three compartments for regulating temperature: the core, the limbs, and a special third group made up of the palms, the soles of the feet and the face. The hairless skin on the palms and soles, called glabrous skin, has a unique arrangement of blood vessels called arteriovenous anastomoses (AVAs). Normally blood flows from arteries to capillaries to veins, but AVAs connect small arteries directly to small veins. They are wide, muscular and controlled by adrenaline-related nerves. Because flow through a tube rises with the fourth power of its radius, small changes in these vessels allow huge amounts of heat to move in or out.

This means the palms, soles and face are the best places to both cool and warm the core and brain. It also means that, contrary to popular belief, most heat is lost through the face, palms and soles rather than the top of the head.

Craig Heller's Palmar Cooling Results

Huberman stresses that this is the work of Craig Heller's lab at Stanford, research first funded by DARPA and now used by many NFL teams, the military, firefighters and construction workers. Participants held a cooled tube in their hands between sets. The crucial detail is that it must not be so cold that it constricts the blood vessels, or heat can't flow out. In one pull-up study, a person who could do sets of 10 did about 100 pull-ups in a fixed time without cooling, about 180 the very next day with cooling after every other set, and, over several weeks of training, around 600 in the same amount of time. A professional football player went from a first set of 40 dips with a steep drop-off to tripling his volume in less than a week.

In a bench press study using 225 pounds, the cooling group roughly doubled its work and outpaced even a comparison group taking the anabolic steroid testosterone cypionate. Importantly, the gains held even when people later trained without cooling, so it served as both a performance boost and a training stimulus that people could recover from. Huberman tried a rough version himself before the episode, cooling his hands and feet in a bucket of slightly cool tap water between sets, and saw a 60% increase in dips in a single session.

Heat, Willpower and Cardiac Drift

Huberman says "your body heat and your willpower are linked in a physiological way." In treadmill studies at a fixed pace, heart rate settles into a steady state, but as the room gets hotter heart rate climbs even though effort stays the same. This is called cardiac drift. The brain seems to combine the heat and effort signals, and when they cross a threshold, we stop. Palmar cooling in these conditions let people go further and longer, with statistically significant results every time, and also protected them from hyperthermia, nerve injury and death. People also felt mentally that they could do more.

The same surfaces work for warming. When a friend became hypothermic on a cold-water swim, Huberman and others warmed him by pressing their chests against him, which he now thinks was the wrong approach. Warming his palms, feet and face would have been better, and post-surgery patients are warmed with socks and gloves for this reason. For people who run cold in winter, warming the face does more than warming anywhere else.

How to Use Cooling at Home

Until commercial devices from Heller's Stanford spin-out company are widely available, Huberman offers simple versions. Between sets, rest your palms in or on a sink of cool water, cooler than body temperature but not ice water, for 10 to 30 seconds at first, then 30 seconds to a minute, adjusting the temperature by trial and error. On a run, pass a frozen juice can or a cold soda can back and forth between your hands so neither gets cold enough to constrict the vessels. People in very hot, high-output jobs such as firefighting use cool face masks briefly, removing them before vasoconstriction sets in. He warns against cooling the core with a cold bath before training on a hot day, a mistake he says has cost some sports teams dearly.

Cooling for Recovery, and the Problem With Ice Baths

Between rounds or at halftime, athletes typically cool the back of the neck, the head or the torso, sometimes with ice vests. Huberman says cooling the face, palms or soles would be far more efficient. Cold showers or ice baths are a poor way to cool quickly because they don't target these portals and can constrict the very vessels needed to dump heat. Splashing cold water on your face or holding a damp, cool cloth to it is often better than jumping in an ice bath.

For recovery between sessions, full-body cold after training can blunt inflammation but also block pathways such as mTOR that drive muscle adaptation, short-circuiting muscle growth. He reserves ice baths and cold plunges for deliberately building brown fat and mental resilience. Citing the book Thermoregulation and Human Performance edited by F. E. Marino, he says the faster you bring body temperature back to baseline after a workout, the faster muscles and tendons recover, ideally by cooling the palms, soles or face.

Caffeine, Pre-Workouts, Alcohol and NSAIDs

Huberman argues that "increasing body temperature prior to working out is the exact wrong thing that one would want to do." He regrets drinking lots of espresso and taking ephedrine before college workouts. For people not used to caffeine, it constricts blood vessels and traps heat, making it a poor choice before exercise. For regular users taking about 100 to 400 milligrams a day, it causes vasodilation instead, so they can take it before training but not after. People who rarely use caffeine should avoid it around exercise. He adds that quitting caffeine takes about three weeks and brings vicious headaches.

Alcohol dilates blood vessels and lowers body temperature, and he mentions an athlete friend who drinks a beer or two after long runs to dump heat, provided alcohol isn't a problem for someone and they are of legal age. More broadly, "anything that you ingest after exercise that would increase body temperature is going to impede recovery." Some endurance athletes use NSAIDs such as Tylenol or Advil to lower body temperature, but these affect the liver and kidneys and should be used cautiously, ideally with a coach. Huberman prefers moderate caffeine and adjustable cooling because you can change the water temperature set to set, whereas a pill can't be taken back once it's in. He adds that eating raises temperature only slightly, so it isn't a concern before training.

Conclusion

Huberman's central message is that heat is the hidden limit on performance: warm muscles fail, and the brain makes us quit to protect us. By using the body's natural radiators, the palms, soles and face, with cool but not icy water, people can dramatically increase strength and endurance work, recover faster and stay safer in the heat. The same knowledge reframes common habits: full-body ice baths right after training may blunt muscle gains, stimulant pre-workouts can hold performance back, and caffeine's effect depends on whether you are used to it. The tools are cheap and flexible enough to experiment with, and Huberman encourages listeners to test them thoughtfully and never push themselves toward overheating.

This is a summary of "Supercharge Exercise Performance & Recovery with Cooling" from Huberman Lab, giving you the GIST so you can decide if you want the REST. Listen to the full episode.