[@hubermanlab] Essentials: Increase Strength & Endurance with Cooling Protocols | Dr. Craig Heller

Link: https://youtu.be/aZklQpFa2kE

Short Summary

Number One Action Item/Takeaway:

Cool the palms of your hands, soles of your feet, and upper face (glabrous skin) to improve performance during both aerobic and anaerobic exercise, especially in hot environments. Avoid cooling the torso or neck as these can trigger vasoconstriction of the heat loss portals.

Executive Summary:

Cooling glabrous skin (palms, soles, and face) is a more effective way to reduce body temperature than traditional methods like ice packs on the torso or neck. Cooling these specialized heat-loss portals can improve athletic performance, allowing for more work and faster cooling rates, leading to conditioning effects and true physiological adaptions. The CoolMitt is a technology designed to efficiently cool the palms of your hands during exercise.

Key Quotes

Here are five direct quotes from the transcript that represent valuable insights:

1. "The most immediate the most immediate impairment of muscle activity, muscle fatigue in other words, is the rise in temperature of the muscle." (Highlights the critical role of muscle temperature in fatigue.)

2. "So, one of the things that can happen when you're overheated is that you can send in a cold stimulus to your thermostat. And that's sort of like wanting to cool your house by putting a wet washcloth over your thermostat. It's doing the wrong thing." (Explains why simply cooling the skin surface (like with a cold towel on the neck) can be misleading and not effectively reduce core temperature.)

3. "So, if you're bicycling on a hot day, you don't want to be grabbing your handlebars all the time. You want to periodically, you know, [...] loosen the grip or if you safely can, you want to actually expose your hands to the world." (Provides a specific, actionable tip for endurance athletes to improve performance by optimizing heat loss from the hands.)

4. "When you're overheated, the direction of flow in those blood vessels reverses. So the cooled blood that's coming from your facial region goes into that circulation and actually is a cooling source for the brain. So you can cool the brain. You can have a cooling effect on the brain by pouring water on on your head." (Reveals a surprising mechanism of brain cooling through facial blood vessels.)

5. "Ice cold is too cold. What that does is that causes reflex vasoc constriction of the very portals that you're trying to maximize the heat loss from. Uh so you stick your hand in cold water. Uh when it comes out it's cold. You just sealed up all the heat in your body." (Explains why methods like ice water may not be as effective due to the body's vasoconstriction response.)

Detailed Summary

Here is a detailed summary of the YouTube video transcript in bullet points, excluding advertisements:

Key Topics:

• The physiological effects of cold exposure (cold showers, ice baths) on the body.
• The impact of temperature on athletic performance, both aerobic and anaerobic.
• The role of glabrous skin (hairless skin on palms, soles, and face) in heat exchange.
• The use of palmar cooling (cooling the palms of the hands) to enhance performance.
• The function of blood flow through specialized blood vessels which shunt the blood from the arteries directly to the veins bypassing the capillaries.
• Discussion of "Cool Mitt" technology.

Arguments and Information:

• Initial Cold Exposure:
  • Cold showers/ice baths induce a "shock" response primarily due to adrenaline release.
  • Vasoconstriction (narrowing of blood vessels) occurs, potentially hindering heat loss, though overall body surface area can still lead to heat loss.
• Heat Loss Mechanisms:
  • Primary sites for heat loss are palms, soles, and upper face due to specialized blood vessels (shunts) that allow rapid heat transfer.
  • These vessels bypass capillaries, enabling high blood flow rates for efficient heat dissipation.
• Cold Shower vs. Immersion:
  • Differences are primarily physical (boundary layer effect). Still water around the skin insulates, while movement disrupts this layer.
• Aerobic vs. Anaerobic Performance:
  • Aerobic: Cold exposure before exercise can increase the body's capacity to absorb heat, potentially improving speed or endurance.
  • Anaerobic: Muscle temperature rises locally during exercise. Heat in the muscle is carried away in the blood.
• Temperature and Muscle Fatigue:
  • Muscle metabolism increases dramatically during anaerobic activity.
  • Local muscle overheating contributes significantly to muscle fatigue and failure.
  • An enzyme critical for energy transfer is temperature-sensitive, shutting down when muscle temperature is too high, leading to failure.
• Cooling Strategies - What Doesn't Work:
  • Applying cold towels or ice to the torso is ineffective due to skin's insulation properties.
  • Cooling the torso can cause the blood vessels to narrow which slows the rate of heat loss.
  • Drinking ice water helps, but has limited capacity.
• Cooling Strategies - Glabrous Skin:
  • The preoptic anterior hypothalamus is the brain's thermostat which requires input from the body's surface where we sense temperature.
  • Cooling the neck/head tricks the brain, potentially masking core overheating.
  • Cooling glaborous skin (palms, soles, face) is the most effective approach.
• Glabrous Skin Details:
  • Hairless skin possesses unique blood vessels that shunt blood directly from arteries to veins for efficient heat transfer.
  • Loosening grip during exercise (e.g., cycling, running) allows better heat loss from palms.
  • Blood from facial regions can cool the brain via flow through skull vessels.
• Hyperthermia Warning Signs:
  • Vasoconstriction and cessation of sweating are late-stage signs.
  • Exhaustion, elevated heart rate are earlier indicators.
• Palmar Cooling Experiment:
  • Football player Greg Clark tripled his dip performance after using palmar cooling.
  • Other studies showed endurance improvements with palmar cooling during treadmill exercise in heat.
• Cool Mitt Technology:
  • Company developing palmar cooling technology: Arteria (coolmitt.com).
  • Cool Mitt is a device that allows users to hold a cool surface, facilitating heat transfer through palms.
  • Optimal cooling temperature is "just cool," not ice cold (ice cold causes vasoconstriction).
  • Standard cooling duration: 3 minutes.
• DIY/Crude Cooling:
  • Frozen peas or blueberries can be used, but effectiveness depends on maintaining warmth on the palms (avoid vasoconstriction).
  • Circulation is crucial; simply planting feet on frozen packs is less effective.
• Cooling Location Effectiveness Comparison
  • Cooling using face, hands and bottoms of the feet will cool twice as fast as putting cold packs into your armpits, your groin or the back of your neck.
• Performance Adaptation:
  • Cooling-enhanced workouts lead to conditioning, improving performance even without cooling in subsequent sessions.