Heart Rate Variability Podcast

This Week in Heart Rate Variability: Metabolic Syndrome, Nerve Blocks, EDS & Autonomic Health In this episode of The Heart Rate Variability Podcast – This Week in HRV, we explore how the autonomic nervous system function connects metabolic disease, genetic disorders, targeted neural interventions, and the future of biofeedback science. Episode Highlights How Metabolic Syndrome drives chronic sympathetic overactivation and reduced HRV Experimental evidence showing how the stellate ganglion block directly alters HRV and sympathetic tone New data validating dysautonomia in Ehlers–Danlos Syndrome using HRV and autonomic testing Why HRV is emerging as a critical clinical and research biomarker A preview of the 2026 AAPB Annual Scientific Meeting and why it matters for clinicians and researchers Featured Studies & Resources Cureus (2025) — Autonomic Nervous System Dysregulation in Metabolic Syndrome https://www.cureus.com/articles/431819-autonomic-nervous-system-dysregulation-in-metabolic-syndrome-an-association-with-hypertension-and-cardiovascular-risk#!/ Autonomic Neuroscience (2025) — Selective Sympathetic Action on HRV After Stellate Ganglion Block https://www.sciencedirect.com/science/article/abs/pii/S1566070225001298 Cureus (2025) — Heart Rate Variability and Intrinsic Autonomic Coupling in Ehlers–Danlos Syndrome https://www.cureus.com/articles/429326-heart-rate-variability-and-intrinsic-autonomic-coupling-in-ehlers-danlos-syndrome?score_article=true#!/ Association for Applied Psychophysiology and Biofeedback (AAPB) About AAPB: https://aapb.org/about 2026 Annual Conference: https://aapb.starchapter.com/meetinginfo.php?id=43&ts=1763415344 Key Takeaway Heart rate variability is a universal marker of resilience, translating metabolic stress, genetic vulnerability, and neural interventions into measurable physiological signals. HRV is no longer just a wellness metric—it's a clinical and scientific lens into autonomic health. Sponsor This episode is sponsored by Optimal HRV, providing evidence-based tools for measuring and training heart rate variability for individuals, clinicians, and organizations. Now offering e-gift cards for HRV training, app access, and professional dashboards. Learn more at www.optimalhrv.com

Episode 15 – This Week in Heart Rate Variability Welcome to this week's exploration of the latest HRV science. In Episode 15, we discuss nine newly published studies that expand our understanding of HRV in mental health, physiology, chronic illness, and digital health innovation. This episode highlights remote biofeedback, pediatric heart dynamics, pregnancy and thyroid status, elite performance, cardiac rehabilitation, personalized training prediction, global research trends, autoimmune flare detection, and neurostimulation safety. Featured Studies: Remote HRV Biofeedback and Mental Health “Efficacy and Methodology of Remote Heart Rate Variability Biofeedback Interventions for Mental Health: A Systematic Review and Meta-Analysis” Vann-Adibe et al., Applied Psychophysiology and Biofeedback (2025) https://link.springer.com/article/10.1007/s10484-025-09750-w Pediatric HRV and Cardiac Complexity “Age-dependent patterns of cardiac complexity unveiled by topological data analysis of pediatric heart rate variability” Domínguez-Monterroza et al., PLOS ONE (2025) https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0337620 Subclinical Hypothyroidism in Pregnancy and HRV “Comparative Evaluation of Thyroid Profiles and Heart Rate Variability in Newly Diagnosed Subclinical Hypothyroid and Euthyroid Pregnant Women” Singh et al., Cureus (2025) https://www.cureus.com/articles/427419-comparative-evaluation-of-thyroid-profiles-and-heart-rate-variability-in-newly-diagnosed-subclinical-hypothyroid-and-euthyroid-pregnant-women?score_article=true#!/ Performance Optimization in Firefighters “Mental imagery and breathing exercises integrated into a standardized warm-up routine enhance sympathetic activation and optimize muscular performance in firefighters” Biéchy et al., PLOS ONE (2025) https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0337431 Innovative Respiratory-Synchronized Pacemaker University of Auckland research feature: “Pacemaker could help the heart heal” Paton, Ben-Tal, Nogaret, and Stiles https://www.auckland.ac.nz/en/news/2025/12/02/pacemaker-could-help-heart-heal.html HRV and Personalized Fitness Modeling “Advancing training effectiveness prediction in mass sport through longitudinal data: A mathematical model approach based on the Fitness-Fatigue Model” Wang et al., PLOS ONE (2025) https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0337824 Global Trends in HRV Research “A Two-Decade Bibliometric Analysis of Heart Rate Variability Research (2005–2024)” Sharma et al., Psychiatry Research (2025) https://www.sciencedirect.com/science/article/pii/S1471015325001254?dgcid=author Predicting Rheumatoid Arthritis Flares with Wearables “Wearable devices detect physiological changes that precede and are associated with symptomatic and inflammatory rheumatoid arthritis flares” Sharma et al., Scientific Reports (2025) https://www.nature.com/articles/s41598-025-29748-y Safety of Paired Associative Stimulation in SCI Rehab “Heart rate variability in patients with incomplete spinal cord injury during a single session of paired associative stimulation” Haakana et al., Scientific Reports (2025) https://www.nature.com/articles/s41598-025-25802-x

In this episode, Matt Bennett talks with Dr. Richard Harris about his article: Single-case report: dynamic changes in cardiac function during shamanic journeying and Qigong meditation Read the full article here: https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2025.1608442/full

In this episode, we dive deep into the latest research from late 2025 and explore the exploding field of Psychophysiology. We look at how Heart Rate Variability (HRV) is becoming the "master key" for detecting everything from complex emotions to psychosis. We also break down a massive new study on how antidepressants shift your physical metabolism, the effectiveness of "light-guided" breathing for office stress, and how VR gaming affects your autonomic nervous system. Links & Resources Mentioned: Clinical Psychiatry & Pharmacology Article: Which Antidepressants Shift Physiology? (Conexiant) Takeaway: A look at how different antidepressant classes impact weight, blood pressure, and heart rate. Paper: Reducing Artifact Preprocessing in HRV-Based Personalized Psychosis Prediction (World Scientific) Takeaway: Using AI to predict psychosis directly from wearable data. Breathing & Interventions Paper: Light-guided resonant breathing enhances psychophysiological stress recovery in a simulated office environment (Nature Scientific Reports) Paper: Resonant breathing in hospitalised psychiatric patients with persistent somatic symptoms (General Psychiatry / BMJ) The Science of Stress & Emotion (HRV) Paper: Measures of the psychophysiological response to recurrent anticipatory stress - the influence of neuroticism (Nature Scientific Reports) Paper: Heart rate variability reveals graded task difficulty effects and sensitization dynamics (Springer / J. Physiol. Anthropol.) Paper: HRV-Based Recognition of Complex Emotions: Feature Identification (MDPI Healthcare) Physiology in Action (VR & Exercise) Paper: Impact of Stereoscopic Technologies on Heart Rate Variability in Extreme VR Gaming Conditions (MDPI Technologies) Paper: A controlled comparative study on the effect of arterial occlusion pressure on immediate sympathetic responses (Nature Scientific Reports)

This Week’s Studies: Cardiac-vagal rhythm echoes on the heartbeat's mechanosensory imprint in the brain Candia-Rivera & Chavez — Communications Biology https://www.nature.com/articles/s42003-025-08969-x Box breathing or six breaths per minute: Which strategy improves athletes' post-HIIT cardiovascular recovery? Kasap & Aydin — PLOS ONE https://doi.org/10.1371/journal.pone.0336615 The tolerance-related psychology and dynamic activity in the peripheral nervous system of Internet Gaming Disorder Chi & Hsiao — BioMedical Engineering Online https://biomedical-engineering-online.biomedcentral.com/articles/10.1186/s12938-025-01471-9 Heart rate variability biofeedback in adults with chronic spinal cord injury: a randomised feasibility study Schoffl et al. — BMC Neurology https://bmcneurol.biomedcentral.com/articles/10.1186/s12883-025-04423-x

Video link: https://youtu.be/3vn_TF-ezTE   In this episode of The Heart Rate Variability Podcast, host Matt Bennett sits down once again with Stephanie White, HRV coach and educator known affectionately as “the HRV Guru.” Together, they dive deep into advanced heart rate variability concepts—especially heart rate fragmentation (HRF), very high frequency (VHF) activity, and new HRV metrics that can reveal hidden issues in autonomic health. Stephanie shares insights from her work with clinicians, coaches, and patients—explaining why sometimes clients can’t reach the “Optimal Zone” in the Optimal HRV app and what physiological patterns might be behind it. She also outlines the importance of minerals, CO₂ balance, and careful data interpretation when working with HRV readings. Key Topics Covered Stephanie’s Background – Her recovery journey from chronic illness using HRV biofeedback and her work with VCU’s Comprehensive Autonomic Center. Why HRV Data Sometimes “Doesn’t Make Sense” – How heart rate fragmentation can hijack HRV signals and confuse traditional measures like RMSSD. RMSSD vs. SDNN – Why SDNN may better capture resonance frequency breathing and coherent sine wave patterns. Understanding Heart Rate Fragmentation (HRF) – How alternating or sawtooth heart rhythms create misleading HRV statistics and mask underlying autonomic issues. Introducing “Very High Frequency (VHF)” – What happens when HRF shifts heart power above 0.4 Hz, and why current HRV software often misses it. The Role of CVNN and PSS – New or underused HRV metrics that can quantify fatigue, allostatic load, and fragmentation. Practical Clinical Applications – How coaches and clinicians can identify HRF, interpret data accurately, and help clients avoid “false high” HRV readings. Mineral Balance and HRV Health – Why calcium, sodium, potassium, and magnesium are crucial for healthy cardiac rhythm and recovery. Building an HRV Coaching Certification Pathway – Stephanie’s vision for “HRV Behavioral Health Coaches” and measurable, data-driven client progress.

Studies & Resources Discussed Insomnia and HRV in Medical Students Publication: Cureus Title: “Insomnia and Its Impact on Psychomotor Reactivity, Autonomic Function, and Psychological Well-Being Among Medical Students: A Cross-Sectional Analytical Study” Authors: Dhanusri, Rajalakshmi, Prakash, Bharadwaj, and Harichandrakumar Key Finding: The severity of insomnia among medical students was associated with slower reaction times and higher psychological distress, while short-term resting HRV remained largely unchanged. Early cognitive and mood changes appear before resting HRV declines, underscoring that subjective fatigue and attention lapses can be earlier indicators than RMSSD or SDNN. Link: https://www.cureus.com/articles/427559-insomnia-and-its-impact-on-psychomotor-reactivity-autonomic-function-and-psychological-well-being-among-medical-students-a-cross-sectional-analytical-study#!/ Meta-Analysis: HRV in Insomnia Disorder Publication: Sleep and Breathing Title: “Heart rate variability in patients with insomnia disorder: a systematic review and meta-analysis” Authors: Zhao and Jiang Key Finding: Across 17 studies and 921 participants, insomnia showed only mild, non-significant reductions in HRV measures such as SDNN and HF-norm. The review emphasizes methodological variability and suggests that chronic insomnia’s autonomic signature is subtle and context-dependent. Link: https://link.springer.com/article/10.1007/s11325-022-02720-0 Sleep Deprivation and HRV Publication: Frontiers in Neurology Title: “Effects of Sleep Deprivation on Heart Rate Variability: A Systematic Review and Meta-Analysis” Authors: Zhang, Niu, Ma, Wei, Zhang, and Du Key Finding: Eleven trials revealed consistent sympathetic dominance after sleep deprivation, as evidenced by decreased RMSSD, increased LF and LF/HF, and stable SDNN. These findings reinforce that RMSSD is the most sensitive marker of HRV for acute sleep loss and stress load. Link: https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2025.1556784/full COMISA: Insomnia and Sleep Apnea Combined Publication: Scientific Reports Title: “Heart Rate Variability Analysis in Comorbid Insomnia and Sleep Apnea (COMISA)” Authors: Martín-Montero, Vaquerizo-Villar, García-Vicente, Gutiérrez-Tobal, Penzel, and Hornero Key Finding: Using over 5,000 overnight ECGs, COMISA patients showed reduced parasympathetic tone while awake and increased sympathetic drive during sleep. This dual imbalance likely explains elevated cardiovascular risk when both disorders coexist. Link: https://www.nature.com/articles/s41598-025-02541-7 Depression and HRV in Students Publication: Kompasiana Title: “Diagnosis of Depression Based on SDNN Indicator of Heart Rate Variability (HRV) in Students” Author: Widya P. Key Finding: In 120 university students aged 18–25, PHQ-9 depression scores correlated negatively with SDNN (r = –0.48, p < 0.001). An SDNN threshold of 50 ms identified moderate-to-severe depression with 82% sensitivity and 77% specificity, suggesting SDNN as a potential physiological adjunct to psychological screening. Link: https://www.kompasiana.com/ola7155/690eaadfed641503d4754d93/diagnosis-of-depression-based-on-sdnn-indicator-of-heart-rate-variability-hrv-in-students#google_vignette Post-PCI Inflammation and Wearable Data Integration Publication: PLOS ONE Title: “Multi-modal inflammatory risk modeling in post-PCI patients using behavioral and physiologic data” Author: Sanghee Kim Key Finding: In 312 post-PCI patients, combining wearable data (steps, sleep efficiency, HRV, SpO₂) with inflammatory biomarkers improved the prediction of hs-CRP reduction. The Transformer-based model achieved an AUC of 0.88, identifying step count and HRV as leading behavioral predictors of inflammation control. Link: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0336394 Sponsor Spotlight Optimal HRV — The app designed to make HRV tracking practical. The latest update introduces full multilingual support (17+ languages), a smoother onboarding process, guided device testing, and enhanced mindfulness playback. Recognition: 2026 Edison Awards Nominee for Innovation. Learn more: Search “Optimal HRV” in your app store.

Studies & Resources Discussed   HRV Biofeedback for PTSD & Chronic Pain Publication: Journal of Affective Disorders Title: "Heart rate variability biofeedback improves co-occurring posttraumatic stress disorder and chronic pain symptoms: A randomised waitlist controlled trial" Key Finding: This is the first RCT for this co-occurring population. Just six weeks of HRV biofeedback (HRVBF) led to a 24.3% decrease in PTSD symptoms and a 24.9% reduction in pain interference. Biofeedback in Pediatric Care Publication: Cleveland Clinic ConsultQD Title: "Biofeedback Interventions With Psychotherapy in Pediatric Care: The Present and the Future" Key Finding: A clinical guide and call to action for integrating biofeedback (like HRV) with psychotherapy to make self-regulation a concrete, measurable skill for children (e.g., pairing HRV biofeedback with exposure therapy for phobias). Slow-Paced Contraction (SPC) Publication: Biosourcesoftware.com Title: "Add Slow-Paced Contraction to Your Practice" Key Finding: This article details the "how-to" for Slow-Paced Contraction, a vital alternative to slow-paced breathing for patients with contraindications (like severe COPD, kidney disease, or metabolic acidosis). Tai Chi & HRV Publication: Medicine Title: "Effects of a Tai Chi dance intervention on the autonomic nervous system in university students" Key Finding: A 16-week Tai Chi intervention was shown to be an effective method to prevent excessive declines in resting HRV in university students, building autonomic resilience. HRV & Non-Suicidal Self-Injury (NSSI) Publication: Taylor & Francis Online Title: "Association between heart rate variability and emotion dysregulation in adolescents with non-suicidal self-injury" Key Finding: This review frames reduced HRV as a key physiological marker of the Emotion Dysregulation and autonomic imbalance that underlies the distress leading to NSSI in adolescents. HRV in IPV Offenders Publication: Journal of Criminal Justice Title: "Diminished vagally mediated heart rate variability in a compassion-eliciting task in intimate partner violence offenders" Key Finding: Intimate Partner Violence (IPV) offenders showed lower vagally mediated HRV during a compassion-eliciting task, suggesting a diminished physiological capacity to connect with others' suffering. HRV & Heart Failure (HFrEF) Publication: Current Cardiology Reviews (via PMC) Title: "Heart Rate Variability and Heart Failure with Reduced Ejection Fraction: A Systematic Review of Literature" Key Finding: A systematic review concluding that autonomic impairment (low HRV) is a hallmark of HFrEF and that abnormally low HRV metrics are a powerful predictor of worse prognosis. HRV & Subclinical Thyroid Dysfunction Publication: Egyptian Journal of Radiology and Nuclear Medicine Title: "Heart rate variability and left atrial stiffness index... in subclinical thyroid dysfunction" Key Finding: Even subclinical thyroid disorders are linked to increased left atrial stiffness (heart stress). The subclinical hyperthyroid group also showed a significantly increased LF/HF ratio, indicating sympathetic dominance. Predicting Vasovagal Syncope Publication: European Heart Journal Title: "An autonomic function-based prediction model for cardioinhibitory vasovagal syncope" Key Finding: Standard HRV metrics could not differentiate syncope subtypes, but a related metric, Deceleration Capacity (DC), was a significant predictor, leading to a functional predictive model. HRV at High Altitude Publication: Journal of Family Medicine and Primary Care Title: "Normative data of heart rate variability in healthy populations residing at high altitudes..." Key Finding: This study establishes new HRV norms for a population living at 3500m, confirming their values differ from sea-level norms. It also found higher parasympathetic tone (RMSSD, pRR50) in females than males. HRV & Cognitive Workload Publication: BMC Nursing Title: "An integrative review of cognitive workload assessment for safety management" Key Finding: This review identifies ECG (for HRV), EEG, and EOG as the top three preferred physiological signals for objectively assessing cognitive workload in real-time, moving beyond subjective surveys. HRV & Shamanic Journeying Publication: Frontiers in Psychology Title: "Dynamic changes in cardiac function during shamanic journeying and Qigong meditation" Key Finding: A fascinating single-case study tracking HRV during shamanic states. Shamanic drumming, for example, decreased heart rate but increased parasympathetic metrics (RMSSD, pNN50), showing a unique physiological profile.

Find the article here: https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2839605 Episode Summary In this insightful episode of The Heart Rate Variability Podcast, host Matt Bennett sits down with Dr. David Eddie, a clinical psychologist and researcher at Massachusetts General Hospital and Assistant Professor at Harvard Medical School. Together, they explore how Heart Rate Variability (HRV) is transforming the landscape of addiction recovery, psychotherapy, and digital mental health. Dr. Eddie shares how HRV can serve as both a biomarker for relapse risk and a tool for emotional regulation, shedding light on how AI, wearable technology, and stress-detection algorithms could revolutionize real-time intervention in substance use treatment. Listeners will gain a deeper understanding of how HRV biofeedback, digital monitoring, and personalized algorithms can support clients in recovery, enhance self-awareness, and inform clinicians’ decision-making in psychotherapy. Key Topics Covered How Dr. David Eddie began his HRV journey during graduate research at Rutgers and the Recovery Research Institute. HRV as a biomarker for pathology and relapse risk in substance use disorder and mental health conditions. Developing stress-detection algorithms that leverage real-time HRV data through wearables and AI. Challenges of variability and individual differences in HRV data across populations. Integrating ecological momentary assessment (EMA) and ambulatory psychophysiological monitoring for clinical insights. How HRV biofeedback supports recovery and emotional regulation in psychotherapy and addiction treatment. Ethical and practical issues around proprietary algorithms, data transparency, and commercial wearables. The future of HRV research, AI integration, and passive monitoring in clinical psychology. Key Takeaways HRV is both a symptom and contributor to addiction and mental health challenges, offering potential for early detection of relapse risk. Wearables and AI can help clinicians intervene in real time — possibly preventing relapse or emotional crises before they occur. Personalized baselines and individual calibration are essential to improve algorithm accuracy for diverse populations. HRV biofeedback provides an accessible, evidence-based method to help clients build resilience, reduce craving, and regulate their nervous system. Future advances will make passive, scalable HRV monitoring a core element of digital mental health and recovery care. About the Guest Dr. David Eddie is a clinical psychologist and researcher at Massachusetts General Hospital’s Recovery Research Institute and the Center for Digital Mental Health, as well as an Assistant Professor of Psychiatry at Harvard Medical School. His work focuses on addiction recovery, psychophysiology, and integrating HRV into digital and clinical interventions. Follow his work at Recovery Research Institute or through Harvard Medical School publications.

Show Notes Resource 1: Title: Associations between mental health disorder symptoms and cardiac function among Royal Canadian Mounted police cadets during the Cadet training program Authors: R.N. Carleton, T.A. Teckchandani, J.P. Neary, J.E. Samayoa, J.M.B. Khoury, K.Q. Maguire, G.P. Krätzig, & G.J.G. Asmundson Publication: Journal of Psychiatric Research Link: https://www.sciencedirect.com/science/article/pii/S0022395625006521 Resource 2: Title: Transgenerational effects of violence in adolescents exposed to grandmaternal intimate partner violence during pregnancy: Heart rate variability and DNA methylation Authors: Nayara Cristina dos Santos Oliveira, Aline Furtado Bastos, Fernanda Serpeloni, & Simone Gonçalves de Assis Publication: Behavioural Brain Research Link: https://www.sciencedirect.com/science/article/abs/pii/S0166432825004735 Resource 3: Title: The role of separation anxiety and autonomic dysregulation in pediatric vasovagal syncope. A cross-sectional study Authors: Gaia Cuzzocrea, Andrea Fontana, Cristiana Alessia Guido, Marta Mascanzoni, Alberto Spalice, Camilla Guccione, Angelos Halaris, Stephen Porges, Lucia Sideli, & Vincenzo Caretti Publication: Journal of Psychiatric Research Link: https://www.sciencedirect.com/science/article/abs/pii/S0022395625006351 Resource 4: Title: Acute cardiovascular and cerebral blood flow responses to high-frequency, low-amplitude vibration on the neck Authors: Viet Q Dinh, Malinda Hansen, K Austin Davis, Lindsey Peralez, & Caroline A Rickards Publication: Journal of Applied Physiology (via PMC) Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12551627/ Resource 5: Title: Autonomic Flexibility and Early Treatment Success: Heart Rate Variability Predicts Remission in First-Episode Psychosis Authors: Judith Rohde, Samantha Weber, Mateo de Bardeci, Aygün Ertuğrul, Grammato Amexi, Eva Schultz, & Sebastian Olbrich Publication: Schizophrenia Bulletin Link: https://academic.oup.com/schizophreniabulletin/advance-article/doi/10.1093/schbul/sbaf191/8305265?login=false Resource 6: Title: Interplay between key metabolic hormones, metabolic factors, renal function, and heart rate variability in humans with obesity Authors: Kitchaya Pongwattanapakin, Chit Care, Chantacha Sitticharoon, Kittikorn Tommy Wilasrusmee, Issarawan Keadkraichaiwat, Pailin Maikaew, & Rungnapa Sririwichitchai Publication: Scientific Reports Link: https://www.nature.com/articles/s41598-025-21757-1 Resource 7: Title: Metabolic Minute – Heart Rate Variability Authors: WCCB Web Staff (featuring Dr. Gary Rolband, Stephen Gage, and Matt Bennett) Publication: WCCB Charlotte Link: https://www.wccbcharlotte.com/2025/10/27/metabolic-minute-heart-rate-variability/