Improve Resilience & Training Capacity: HRV, Respiratory Rate, RHR

This episode of the "Perform" podcast, hosted by Dr. Andy Galpin, delves into the fascinating science and practical application of consciously controlling the autonomic nervous system (ANS). Often considered involuntary, Dr. Galpin explains that aspects like heart rate, body temperature, and stress responses can be influenced and even controlled through dedicated practice and specific techniques. Using examples ranging from the TV show "The Office" to documented feats by Swami Rama and Tibetan monks practicing Tummo meditation, the episode highlights the potential for physiological self-regulation. The discussion covers understanding the sympathetic ('fight or flight') and parasympathetic ('rest and digest') branches of the ANS, key metrics for assessing nervous system state like Heart Rate Variability (HRV) and respiratory rate, and a wide array of tools and strategies—both acute and chronic—to build nervous system resilience. This information is valuable for anyone seeking to improve stress management, enhance physical and mental performance, optimize recovery, and gain greater control over their physiological state.

Key Insights / Core Messages

• It is scientifically documented and practically possible to exert conscious control over aspects of the autonomic nervous system (ANS), including heart rate and body temperature, which are typically considered involuntary physiological functions.
• Heart Rate Variability (HRV), the variation in time between heartbeats, serves as a primary biomarker for assessing the balance between the sympathetic (stress) and parasympathetic (rest) nervous systems. Interpreting HRV requires context, focusing on personal trends and stability over absolute numbers, as it's influenced by genetics, age, measurement devices, and lifestyle factors.
• Beyond HRV, respiratory rate and CO2 tolerance are crucial, sensitive indicators of nervous system state. Elevated respiratory rates (especially above 16 breaths/min at rest) or poor CO2 tolerance can signal chronic over-breathing patterns or heightened stress sensitivity, sometimes revealing issues not fully captured by HRV alone.
• The ultimate goal is not merely relaxation (down-regulation) but building nervous system *resilience*. This involves widening the system's tolerance range (Dr. Galpin uses a "highway analogy") to handle stressors effectively without triggering excessive or prolonged negative physiological or psychological responses. This resilience requires capacity in *both* up-regulation and down-regulation.
• Interventions for nervous system control can be divided into *acute* methods (providing immediate state shifts, like specific breathing exercises, Valsalva maneuver, or cold exposure) and *chronic* methods (aiming for long-term baseline shifts through consistent practice, such as specific exercise regimens, structured breathwork protocols, biofeedback, and sleep hygiene).
• Achieving chronic improvements in nervous system resilience typically requires consistent, dedicated practice (e.g., 10-15 minutes daily) over several weeks (often 4-8 weeks for significant change), similar to building physical strength or undergoing desensitization therapy, before transitioning to a less frequent maintenance routine.
• Effective breathwork protocols for chronic stress and anxiety reduction generally involve sessions longer than five minutes, multiple times per week, often guided initially, avoiding exclusive reliance on fast breathing techniques, and requiring sustained practice over weeks to yield lasting benefits.

Understanding the Nervous System and Control

Dr. Galpin begins by differentiating the Central Nervous System (brain, spinal cord) from the Peripheral Nervous System (everything else). The focus is primarily on the Autonomic Nervous System (ANS), a branch of the peripheral system governing largely involuntary functions. The ANS is further divided into the sympathetic system (associated with 'fight or flight', arousal, stress response) and the parasympathetic system (associated with 'rest and digest', calm, recovery). While often simplified, these systems exist on a spectrum, toggling back and forth rather than being simple on/off switches. Dr. Galpin references historical and scientific examples, like Swami Rama dramatically altering his heart rate and body temperature while monitored by scientists, and Tibetan monks drying wet sheets with body heat using Tummo meditation, to establish that conscious control over these 'autonomic' functions is possible. The episode's aim is not to teach constant micromanagement of the nervous system, which should ideally run efficiently in the background, but to equip listeners with the understanding and tools to consciously recalibrate or influence it when necessary, distinguishing between acute (immediate) adjustments and chronic (long-term baseline) changes.

Building Nervous System Resilience: The Highway Analogy

A central theme is building nervous system *resilience* rather than merely seeking relaxation or heightened sensitivity. Dr. Galpin uses the "highway analogy": it's preferable to widen the highway (increase the range of physiological states the nervous system can handle without issue) than to simply become a more careful driver on a narrow road where small deviations lead to hitting the guardrails (experiencing significant negative consequences from stressors). This resilience means being able to experience both high sympathetic activation and deep parasympathetic states without being overly reactive or getting stuck in one mode. This involves training the system's ability to both up-regulate (activate) and down-regulate (calm) effectively. The concept of Hormesis is relevant here: applying controlled, manageable stressors (like specific breathwork patterns, exercise, or cold exposure) can trigger adaptive responses that strengthen the system's overall resilience, much like exercise strengthens muscles.

Investigating Your Nervous System: Key Metrics

Dr. Galpin introduces his "3 I's" framework: Investigate, Interpret, Intervene. Investigation involves measuring the nervous system's state. Common methods include:

• Performance-Based Tests: Often used in sports, these include daily vertical jump height, grip strength, reaction time tests, or even flexibility measures (like sit-and-reach). Decreases can indicate nervous system fatigue.
• Psychological Assessments: Subjective measures like mood ratings, perceived fatigue (RPE), or willingness to train correlate surprisingly well with objective physiological markers in large datasets.
• Physiological Markers: While blood/saliva tests exist (covered in previous episodes), this episode focuses on respiratory physiology:
  • Resting Heart Rate (RHR): Less sensitive; significant changes usually indicate chronic, long-term stress or overtraining. Not a primary daily metric.
  • Heart Rate Variability (HRV): The variation in time *between* consecutive heartbeats. Higher variability generally indicates greater parasympathetic activity (more relaxed/recovered), while lower, more metronomic variability suggests sympathetic dominance (stressed). It's influenced by genetics (roughly 50%), lifestyle, age (though possibly mitigated by fitness), and fitness levels (moderately correlated with VO2 Max). HRV is linked to attention, emotional control, resilience under stress, and numerous health outcomes (cardiovascular, mental health, inflammation). Dr. Galpin recommends chest straps (like Polar H10) paired with apps (like Optimal HRV) for accurate real-time measurement, deeming them superior to wrist/finger-based devices.
  • Respiratory Rate (RR): Breaths per minute. Provides distinct information from HRV, is highly sensitive to changes in nervous system load (though non-specific about the cause), and may sometimes show changes before HRV does. Measured by most wearables, but focus should be on trends due to differing calculation methods.
  • CO2 Tolerance: Assesses how well the body handles carbon dioxide buildup, often measured via specific breath-hold tests (like Brian McKenzie's protocol). CO2 levels primarily drive the urge to breathe and regulate blood pH. Chronic over-breathing (often linked to chronic stress) leads to low CO2 (hypocapnea), causing issues like alkalinity, vasoconstriction (reduced blood flow), and potentially becoming a self-sustaining pattern. Poor CO2 tolerance often aligns with higher RR.

Interpreting the Data: Context is Key

Interpreting these metrics requires careful consideration:

• HRV Interpretation: Avoid fixating on absolute numbers or comparing across different devices/people. Focus on your consistent trends over time. Calculate your personal average and standard deviation over ~30 days. A stable HRV (low deviation) generally indicates better resilience than large, erratic swings (hyper-reactivity). Key factors influencing HRV include sleep regularity (critical!), alcohol consumption, overall health habits, significant weekly fluctuations in exercise ("weekend warrior" effect), and potentially meal timing (anecdotal link between OMAD and compromised HRV observed). Action based on HRV changes depends on context: an acute drop during an intentional high-stress training block might be expected, whereas the same drop during a recovery or performance phase warrants intervention (acute state shifters for short-term issues, chronic solutions for persistent problems).
• Respiratory Rate Interpretation: A resting rate consistently above 16 breaths/minute is a red flag potentially indicating chronic over-breathing and is linked to various negative health outcomes. Rates between 10-14 are generally good, with 15 being borderline. When troubleshooting high RR, investigate potential causes sequentially: poor breathing mechanics, nasal blockages/allergies (prioritize fixing nasal breathing), dehydration, poor CO2 tolerance, ingrained breathing patterns/habits, and finally, general elevated stress load.
• General Caveat: Never rely on a single metric. Use a combination of objective data and subjective feeling (interoception) to make informed decisions. Don't let wearables dictate your life based on a single day's score without considering the bigger picture.

Intervening: Tools and Techniques for Control

Dr. Galpin outlines numerous interventions, categorized as acute or chronic:

• Acute State Shifters (Immediate Effect): These tools change your physiological state right now. Examples include:
  • Physical actions like flexing hard or yelling (increase arousal) or progressive muscle relaxation (decrease arousal).
  • Short, intense breathwork patterns (e.g., hyperventilation for energy).
  • Cold exposure: Causes an initial sympathetic surge, followed by a significant and prolonged parasympathetic rebound (higher HRV) lasting hours.
  • Visual resets: Specific eye movement drills (e.g., eye circles, "smooth H") can rapidly shift nervous system state.
  • Modified Valsalva maneuver: A specific technique involving breath-holding and creating 360-degree intra-abdominal pressure for ~10 seconds, causing a large heart rate swing that results in a lower post-maneuver baseline (strong parasympathetic effect). Safety precautions are essential (avoid if prone to fainting, near water, etc.).
  • Vagal Nerve Stimulators (VNS): Prescription devices (like GammaCore) appear effective, but evidence for commercially available, non-prescription VNS devices is currently weak according to Dr. Galpin.
• Chronic Baseline Shifters (Long-Term Resilience): These require consistent practice over weeks (typically 4-8 weeks for primary effects, then maintenance) based on the principle of desensitization/adaptation.
  • Exercise: All forms (strength, cardio, HIIT) contribute to nervous system resilience. HIIT may be particularly potent for HRV, but appropriate dosing is key to avoid overtraining. Adjusting type/intensity based on current training status and goals is important.
  • Breathwork (Chronic): Foundational steps include reducing overall sensory arousal (more quiet time) and increasing nasal-only breathing. If specific protocols are needed, effective ones for stress/anxiety (per HHPF review) typically involve: sessions >5 minutes, multiple times per week, guided instruction initially, avoiding *solely* fast/hyperventilation techniques, and consistency over 4-8 weeks. Combining up-regulating and down-regulating patterns within a session often yields a stronger parasympathetic adaptation (Hormesis).
  • Biofeedback: Training awareness and control.
    • Internal Focus: Practices like meditation (Waking Up app mentioned as a good guided resource), "Gear 1 Walking" (walking while maintaining a specific nasal breath cadence like 2-sec in / 2-sec out), or using cold exposure to practice regaining breath control during stress.
    • External Focus: Using technology to provide real-time physiological feedback. Examples range from simple tactile cues (like wearing a weight belt loosely to feel core/diaphragm engagement during breathing) to sophisticated HRV Biofeedback / Resonance Breathing. The latter involves using apps (like Optimal HRV) to identify an individual's *personal* resonant breathing frequency (typically 4-6.5 breaths/min) where HRV metrics (especially LF power and amplitude, indicating vagal tone and resilience) are maximized, and then practicing breathing at that specific cadence for ~20 min/day over several weeks. High-end tools like the Shiftwave chair offer multi-sensory biofeedback experiences.
  • Supplements (Chronic): Evidence for chronic HRV improvement is limited. Omega-3s show some potential (small effect). Watermelon juice (citrulline) and Ashwagandha might act as "stress inoculators," reducing the negative impact of stressors rather than raising baseline HRV. Low Vitamin D and B12 levels are associated with low HRV, but intervention data showing improvement upon supplementation (especially if not deficient) is lacking.

Conclusion

Dr. Galpin concludes by emphasizing that while controlling the nervous system takes deliberate effort, the potential benefits for resilience, performance, and well-being are significant. He stresses the importance of understanding the difference between acute fixes and chronic adaptations, using the right tools for the job, and maintaining consistency, especially with chronic practices (stimulate, don't annihilate). Reducing overall arousal and actively identifying and engaging in personalized recovery-promoting activities are foundational steps. Individuals should also consider their own tendencies—whether they are "big feelers" (hyper-aware) or "dull knives" (less aware)—when choosing tools. By applying these principles and experimenting with the techniques discussed, listeners can work towards a more resilient and adaptable nervous system.