Modern WisdomHow To Improve Your Heart Rate Variability (HRV) - Dr Leah Lagos
CHAPTERS
- 0:00 – 0:52
HRV origins: from fetal monitoring to a broad clinical marker
Leah Lagos traces HRV’s early use in obstetrics to predict fetal vitality, then its adoption as a cardiovascular and clinical indicator. She explains how HRV correlates with diverse conditions and how her work shifted the focus toward optimization for healthy, high-performing people.
- •HRV first used by doctors to assess unborn baby vitality
- •Later applied to cardiovascular health and many clinical conditions
- •Correlations with fibromyalgia, IBS, depression, anxiety
- •Shift from disease-detection to performance and well-being optimization
- •Her research/practice focus over the last ~17 years
- 0:52 – 3:41
What HRV actually measures: variability, RSA, and autonomic flexibility
HRV is framed as the variability between heartbeats, but Leah emphasizes an intuitive way to understand it via respiratory sinus arrhythmia (RSA). Bigger, smoother inhale-exhale heart-rate “waves” generally reflect more resilience, flexibility, and adaptive capacity under stress.
- •HRV = millisecond variability between heartbeats
- •Simple public takeaway: higher (within your range) often signals greater resilience
- •RSA explanation: inhale raises HR, exhale lowers HR
- •Goal is flexible, ocean-like oscillations rather than rigidity
- •Autonomic flexibility matters more than being ‘stressed vs not stressed’
- 3:41 – 6:55
Why HRV drops under stress: energy conservation, immobilization, and rumination
They explore why sympathetic arousal tends to reduce HRV, including a hypothesized “reptilian” immobilization response that conserves energy. The modern problem is that stress often persists via rumination, keeping the nervous system constrained longer than needed.
- •Stress commonly reduces HRV and narrows ‘autonomic bandwidth’
- •Hypothesis: immobilization/conservation response can be adaptive short-term
- •Modern life extends stress through rumination beyond the triggering event
- •‘Just let it go’ is hard because much stress persistence is physiological
- •Bottom-up regulation (body → mind) can be more effective than purely cognitive approaches
- 6:55 – 9:33
What determines your HRV range: biology, lifestyle, sensitivity, and baroreflex gain
Leah explains why comparing HRV numbers across people is often misleading: everyone has an individual range shaped by many variables. Causes of low HRV can include medical issues, chronic stress, sleep, alcohol, training load, and even extreme caffeine intake, while physiological sensitivity can amplify reactivity.
- •HRV range is individual; comparisons (e.g., athletes) are often unhelpful
- •Low HRV can sometimes signal underlying clinical conditions
- •Chronic stress, poor sleep, alcohol, and inactivity can depress HRV
- •Some people are ‘physiologically gifted’/more sensitive with larger stress reactivity
- •Baroreflex gain influences precision of HR and blood pressure regulation
- 9:33 – 11:10
How low HRV can feel: myopic thinking, irritability, and reduced self-control
Rather than a universal symptom list, Leah emphasizes individualized awareness—some people can learn to sense when HRV is low before checking a wearable. Common subjective patterns include feeling more reactive, mentally ‘stuck,’ and less emotionally regulated.
- •Many can’t identify low HRV if it’s their baseline; awareness can be trained
- •Athletes sometimes train to predict HRV state before checking scores
- •Low HRV often feels like mental myopia, irritability, faster reactivity
- •No one-size-fits-all experience; track your own patterns
- •Focus on controllable variables to move toward the top of your range
- 11:10 – 14:14
HRV and the brain: cognitive dexterity, inhibition, and the prefrontal cortex
Research has expanded HRV’s significance beyond resilience to include brain function—particularly cognitive flexibility and inhibition. Leah connects strong HRV oscillatory capacity with the ability to focus deeply, zoom out contextually, pause before reacting, and regulate thoughts via prefrontal mechanisms.
- •HRV reflects adaptability and rapid return to baseline after arousal
- •Recent work links HRV to brain function and cognitive performance
- •‘Cognitive dexterity’ parallels physiological oscillation capacity
- •Inhibition: screening negative thoughts and pausing before reacting
- •HRV training influences prefrontal lobe function and self-regulation
- 14:14 – 15:52
Heart health and longevity: why higher HRV often signals better cardiovascular efficiency
Leah affirms a strong evidence base linking low HRV with cardiovascular conditions and higher HRV with longevity. In her 12-week training experience, people often see resting heart rate drop even without changes in physical activity, suggesting improved cardiovascular efficiency.
- •Low HRV correlates with cardiovascular conditions in research
- •Higher HRV associated with longevity and health resilience
- •HRV training can reduce baseline heart rate by ~5 bpm for some
- •Improvements can occur independent of changes in exercise
- •Clients report broad life impact beyond ‘just the heart’
- 15:52 – 20:47
Two pathways: raising baseline HRV vs ‘hacking’ HRV with wearables and habits
Leah distinguishes long-term baseline improvement (trait change) from short-term state manipulation (hacks). Baseline gains come from a structured 10–12 week protocol that improves unconscious regulation; hacking uses self-tracking to identify personal variables that raise or lower HRV day-to-day.
- •Baseline training aims to improve HRV without conscious intervention
- •Requires consistent practice over ~10–12 weeks
- •Mechanism: improved baroreflex gain and faster parasympathetic recovery
- •HRV ‘hacking’ uses wearables to identify personal drivers (sleep, alcohol, exercise, conflict)
- •Goal: build your own calibration ‘algorithm’ from data
- 20:47 – 24:31
Resonant frequency breathing: the mechanism, discovery, and 10-week protocol
Leah describes resonant sinus arrhythmia work originating with Russian cosmonaut research and later clinical applications for PTSD, depression, asthma, and more. The training identifies an individual resonant breathing rate that maximizes HR oscillations, then uses twice-daily practice to strengthen homeostatic regulation and stress recovery.
- •Resonant frequency relates to a systemic activation frequency (often described as ~0.1 Hz)
- •Activates multiple vagal afferent pathways (brain–heart–gut)
- •Used clinically across conditions; later adapted for elite performance
- •Protocol: weekly sessions + daily practice to maximize oscillations and baroreflex gain
- •Later sessions focus on state shifting: sympathetic ↔ parasympathetic control on demand
- 24:31 – 27:14
Finding your ideal breath rate and why a pacer matters for cognitive effects
They clarify resonant frequency typically falls between ~5 and 6.5 breaths per minute and is individualized. Leah explains why visual pacers enhance cognitive benefits: syncing breath to a pacer trains attention alongside physiological optimization, increasing blood/oxygen flow to the prefrontal cortex.
- •Typical resonant range: ~5 to 6.5 breaths per minute, individualized
- •Resonant rate is usually identified early (often session one) with refinements afterward
- •Breathing from the abdomen and attention control are integrated
- •Using a visual pacer (app cue) improves cognitive outcomes vs eyes-closed/music
- •Pacer options: simple breath pacer apps; Elite HRV offers a guided protocol
- 27:14 – 30:22
Does practice change daily breathing? Training the heart first, then maintenance dosing
Leah reframes the goal: the twice-daily sessions primarily train heart rhythms, with baseline changes often appearing around week four. After completing the protocol, maintenance requires less volume—similar to keeping muscle gains—with dosing adjusted to how benefits feel over time.
- •Primary target is heart rhythm patterns, not just breath rate
- •By ~week 4, trained heart pattern can begin to show up at baseline
- •Maintenance often: 15 minutes, 3–4 times per week (individualized)
- •Some need periodic ‘surges’ (e.g., another 10-week block) if benefits wane
- •Titrate practice based on cognitive/energy signals and goals
- 30:22 – 35:07
How to breathe during the day: ‘Power of Five,’ 4-in/6-out, cues, and habit pairing
Outside formal training, Leah recommends short, situational breathing interventions to reset anxiety and improve decision-making. She shares practical cues (phone reminders, before meals) and a performance-friendly 4-in/6-out cadence with counting to quiet racing thoughts quickly.
- •Use breathing to influence emotion, decisions, and behavior—not just calmness
- •‘Power of Five’: five resonant breaths to reset during anxiety or stress
- •Athlete tool: 4 seconds in, 6 seconds out to downshift arousal
- •Counting occupies cognitive resources, reducing rumination during short resets
- •Cues: phone vibrations, pairing with habits (e.g., before meals) to stay calibrated
- 35:07 – 39:06
Nasal breathing and HRV: individualized testing and what she sees most often
Leah addresses nasal breathing’s popularity and describes what she observes clinically: many people show stronger HRV increases with inhale through the nose and exhale through the mouth (pursed-lips style) than with fully nasal breathing. She stresses individual variability and prioritizes what the data and the person’s felt experience show.
- •Nasal breathing doesn’t universally outperform other strategies for HRV
- •Often: nose inhale + mouth exhale increases HRV more in moment-to-moment testing
- •Possible mechanism: increased peak expiratory flow and cardiovascular effects
- •Defers to individual response and comfort; no one-size-fits-all
- •Some athletes report endurance benefits (less fatigue) with her preferred pattern
- 39:06 – 44:30
HRV vs VO2 max and training effects: what HRV adds + using HRV to test interventions
Leah explains HRV training complements fitness but offers something distinct: a reflexive, unconscious stress-modulation capacity that VO2 improvements don’t directly provide. She also shares examples of how HRV tracking can reveal which exercises and interventions (from running distance to acupuncture) shift someone’s physiology.
- •VO2 max and HRV practices work well together; neither is ‘better’ universally
- •HRV training builds an unconscious reflex to modulate stress
- •She collaborates with trainers rather than prescribing exercise programs directly
- •HRV can identify individualized ‘sweet spots’ (e.g., specific run/swim distances)
- •HRV used to evaluate interventions like acupuncture, supplements, and light exposure
- 44:30 – 48:12
Measuring HRV well: nocturnal vs morning readings, movement artifacts, and device options
They cover common measurement errors: movement, restless sleep, alcohol/late meals, and other artifacts can skew readings. Leah recommends treating data as information rather than panic fuel, and she notes options like Oura for nocturnal tracking and Polar straps for higher reliability and in-the-moment assessments.
- •Nocturnal HRV is often reliable but can be skewed by late eating/drinking/restlessness
- •Movement artifacts (even foot twitches) can distort readings
- •Don’t panic over anomalies; look for patterns and context
- •Tools mentioned: Oura ring, Elite HRV + sensors, Polar straps (research-grade reliability)
- •Polar can also help assess state pre-game and train rapid downshifts in arousal
- 48:12 – 55:01
Vagal practices, troubleshooting ‘non-responders,’ and the biggest HRV training pitfalls
Leah discusses additional parasympathetic activators (e.g., sound baths) but urges people to start by understanding their own patterns and goals. She explains that apparent non-response is often due to chronic stress, overtraining, poor recovery, or trauma states—and that the most common pitfall is trying too hard and making practice perfectionistic rather than gentle and consistent.
- •Many ‘vagal tone’ interventions exist, but self-knowledge and measurement come first
- •Commitment matters: 15 minutes twice/day for ~10 weeks to reliably raise baroreflex gain
- •Non-response usually prompts detective work: chronic stress, overtraining, lack of recovery
- •PTSD/startle states can blunt early effects; persistence and safety cues help
- •Most common pitfall: perfectionism/over-effort; treat practice as light, playful ‘spa time’
- 55:01 – 55:45
Resources and where to find Leah Lagos
Leah shares where listeners can learn the full HRV biofeedback protocol and connect with her work. Chris closes out the episode with pointers to further clips.
- •Protocol available in her book: 'Heart, Breath, Mind'
- •Book available via major retailers (Amazon, Barnes & Noble, others)
- •Website: drleahlagos.com
- •Episode wraps with thanks and sign-off
