Huberman Lab Podcast Summary
Episode: Essentials: Increase Strength & Endurance with Cooling Protocols | Dr. Craig Heller
Release Date: August 7, 2025
Host: Andrew Huberman, Ph.D.
Guest: Dr. Craig Heller
Introduction
In this episode of the Huberman Lab podcast, Professor Andrew Huberman welcomes Dr. Craig Heller, an expert in physiology and performance enhancement, to discuss the role of cooling protocols in increasing strength and endurance. The conversation delves into the physiological mechanisms behind cold exposure, its impact on athletic performance, and practical applications for both aerobic and anaerobic activities.
Physiological Effects of Cold Exposure
Cold Showers vs. Ice Baths
Dr. Heller begins by explaining the immediate physiological responses to cold exposure, such as cold showers and ice baths. He notes that "when you get into a cold shower or an ice bath, you experience a tremendous shock that results in a spike of adrenaline" (00:57). However, he emphasizes that this adrenaline surge doesn't necessarily translate into long-term physiological or performance benefits.
Key physiological changes include:
- Vasoconstriction: Cold exposure stimulates vasoconstriction, which initially makes it harder for the body to dissipate heat by reducing blood flow to the skin.
- Heat Loss Mechanisms: Despite vasoconstriction, immersion in cold water facilitates significant heat loss due to the large surface area involved. Critical areas for heat dissipation include the palms, soles of the feet, and upper face.
Impact on Aerobic Performance
Enhancing Heat Tolerance for Endurance Activities
When engaging in aerobic activities, the body gradually produces heat, increasing core temperature and potentially impairing performance. Dr. Heller explains that “the benefit of a cold bath or a cold shower before aerobic activity is that you increase the capacity of your body mass to absorb that excess heat” (04:08). This pre-cooling extends the time it takes for an athlete to reach critical temperature thresholds that could hinder performance.
For example, taking a cool shower before a long run can delay the onset of heat-induced fatigue, allowing for increased speed or extended endurance. Dr. Heller elaborates, "it'll take them longer to get to the sweat point and to heat up" (04:26), which can translate to better performance outcomes.
Impact on Anaerobic Performance
Local Muscle Temperature and Strength
In the context of anaerobic activities, such as strength training, local muscle temperature plays a crucial role. Dr. Heller discusses how muscle temperature affects performance, particularly in large compound movements like barbell squats. "The temperature of those muscles will go up," leading to muscle failure due to an enzyme-sensitive mechanism that halts fuel supply to the mitochondria when temperatures exceed optimal levels (05:14).
He states, "the most immediate impairment of muscle activity, muscle fatigue, in other words, is the rise in temperature of the muscle" (07:09). This indicates that managing local muscle temperature can directly influence an athlete's ability to perform additional repetitions or maintain strength during training sessions.
The Role of Glabrous Skin in Cooling
Specialized Heat Loss Portals
A significant portion of the discussion revolves around the concept of glabrous skin—hairless areas of the body such as the palms, soles, and upper face. Dr. Heller explains that these areas contain specialized blood vessels that act as heat loss portals. "The pads of the feet and for the primates, upper part of the face... evolved these special blood vessels early on" (17:13).
These portals allow for efficient heat dissipation through direct blood flow from arteries to veins, bypassing the capillaries. This mechanism is essential for maintaining core temperature, especially during intense physical activities. Dr. Heller illustrates, "the cooling rate was double" when using these portals compared to traditional methods like placing cold packs in the armpits or neck (34:07).
Practical Cooling Protocols for Enhanced Performance
Cooling Techniques and Their Applications
Dr. Heller introduces practical methods to leverage glabrous skin for cooling:
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Cool Mitts (Coolmit Devices):
- These are specialized mitts designed to cool the palms without triggering vasoconstriction.
- “People have used frozen peas as a crude method, but specialized devices like Coolmit provide more controlled cooling” (32:16).
- Participants typically use the mitts for three minutes during rest periods between sets, optimizing heat loss without significant boundary layer formation that impedes cooling.
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Avoiding Excessive Grip Tightness:
- “Gripping handlebars too tightly can limit performance by increasing local muscle temperature” (18:12).
- Athletes are encouraged to maintain a relaxed grip to enhance heat dissipation through the palms.
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Innovative Cooling Methods:
- Applying cold packs to the face or using cold sponges over the head can assist in cooling the brain, though this approach requires careful consideration to avoid misleading the body’s thermoregulatory systems (13:34).
Case Study: Enhanced Dip Performance
Dr. Heller shares an anecdote about NFL player Greg Clark, who significantly improved his dip performance using cooling protocols. "He tripled his number of dips, going from 40 in the first set to 300 dips over a month" (25:49). This remarkable improvement was achieved by incorporating Coolmit devices during rest periods, allowing for faster recovery and sustained performance across multiple sets.
Technological Advancements: Coolmit Devices
Introducing Coolmit for Optimal Cooling
The discussion highlights the development of Coolmit, a specialized device designed to target glabrous skin for effective cooling. Unlike traditional methods like ice baths or cold towels, Coolmit maintains a moderate cooling temperature to prevent vasoconstriction while maximizing heat loss.
- Ease of Use: Athletes can use Coolmit for three-minute intervals during rest periods between sets.
- Effectiveness: Studies show that using Coolmit can double the cooling rate compared to conventional cooling methods (34:07).
- Adoption: Coolmit has been adopted by various professional sports teams, including NFL, NBA, and Olympic teams, indicating its efficacy and reliability in high-performance environments.
Dr. Heller suggests that until Coolmit becomes widely available, individuals can experiment with cooling techniques using frozen items like peas, though he acknowledges these are less effective due to poor heat transfer dynamics (32:16).
Long-Term Benefits and Adaptations
Sustaining Performance Gains Without Continuous Cooling
A critical insight shared by Dr. Heller is the potential for cooling protocols to induce long-term performance enhancements. "You keep your gains. It's a true conditioning effect" (35:11). By allowing athletes to perform more work during training sessions, their muscles adapt by increasing the number of contractile elements and overall muscle size, leading to sustained strength and endurance improvements even without continuous cooling.
Conclusion and Takeaways
This episode underscores the significant role that strategic cooling can play in enhancing athletic performance. By targeting glabrous skin areas—such as the palms, soles, and upper face—athletes can optimize heat dissipation, delay fatigue, and increase overall work capacity. The introduction of innovative technologies like Coolmit offers practical solutions for both professional and recreational athletes seeking to leverage the physiological benefits of controlled cooling.
Notable Quotes:
- "You have to keep in mind whether you're talking about aerobic activity or anaerobic activity... so that you increase the capacity of your body mass to absorb that excess heat." (04:08)
- "The most immediate impairment of muscle activity, muscle fatigue, in other words, is the rise in temperature of the muscle." (07:09)
- "The glabrous skin portals can cool you twice as fast as putting cold packs into your armpits, your groin or back of neck." (34:07)
- "He essentially tripled his number of dips... by incorporating cooling during rest periods." (25:49)
Harnessing the science of cooling protocols can provide a competitive edge in both strength and endurance sports. By understanding and applying these insights, athletes can push their limits more effectively while maintaining optimal physiological function.