Heart Rate Variability Podcast

In this episode, Matt Bennett interviews Dr. Jennifer S. Addleman and Nicholas S. Lackey about their recent article Heart Rate Variability Applications in Medical Specialties: A Narrative Review. You can find the article here: https://link.springer.com/article/10.1007/s10484-025-09708-y.

Dr. Jennifer S. Addleman, DO, CSCS, is a resident physician and certified strength and conditioning specialist (CSCS). She is currently completing her intern year in the Sutter Roseville Transitional Year Residency Program, followed by advanced training in Physiatry at the Stanford Physical Medicine and Rehabilitation Residency Program. Dr. Addleman is active in research involving gait analysis, wearable technology, and heart rate variability. She is passionate about exploring the applications of HRV across medicine and strength and conditioning.

Nicholas Lackey, PhD, BCB, is a Psychology Postdoctoral Resident with the Kaiser Permanente Mental Health Training Program in Northern California. He earned his PhD from Alliant International University in San Diego, during which he also completed the requisite experience for his Board Certification in Biofeedback. He explored research on meta-analyses and then on the implementation of Biofeedback. His dissertation explored the efficacy of a scale in examining types of chronic pain and Central Sensitization. Dr. Lackey aims to continue his career in Health Psychology and to examine the intersection of Psychology and Medicine through multidisciplinary collaboration and practice.

Here is their previous article on strength and conditioning training and heart rate variability mentioned in the episode: https://pubmed.ncbi.nlm.nih.gov/38921629/

This Week in HRV - Episode 22

In this episode of "This Week in HRV", Matt Bennett explores four recent studies that broaden our perspective on autonomic regulation across diverse physiological contexts. This week’s collection highlights the nuances of female reproductive physiology as captured by wearables, the specific cardiovascular mechanics of volitional sighing, the superior recovery potential of yoga practice, and the intricate neural coupling between the heart and brain during complex motor tasks. Together, these papers underscore the nervous system's adaptability to hormonal, behavioral, and cognitive demands.

1. Wearable-Derived Heart Rate Variability Across the Menstrual Cycle, Hormonal Contraceptive Use, and Reproductive Life Stages in Females: A Living Systematic Review

Authors: Eline de Jager, Brian Caulfield, Evgenia Angelidi, Brian MacNamee & Sinead Holden

Journal: Sports MedicineShutterstock

This systematic review aggregates data from wearable technology to map HRV trends across the female reproductive lifespan. The authors examine how natural menstrual cycle phases, hormonal contraceptives, and different reproductive stages influence autonomic metrics. The findings emphasize the importance of context when interpreting wearable data in females, as hormonal fluctuations drive distinct shifts in autonomic balance that must be distinguished from training load or stress.

https://link.springer.com/article/10.1007/s40279-025-02388-y

2. Dissecting Cardiovascular Responses to a Fixed-Interval Volitional Sighing Protocol Using a Mixed Modeling Approach

Authors: Neel Muzumdar, Kelly Sun, Samuel Zhang, Kelsey Piersol, Anthony P. Pawlak, Marsha E. Bates & Jennifer F. Buckman

Journal: Psychophysiology

Investigating the mechanics of breathwork, this study utilized a mixed modeling approach to analyze cardiovascular responses to a specific protocol of volitional sighing. The research dissects how fixed-interval sighing alters heart rate dynamics, providing granular insight into how this specific respiratory behavior—often used for acute stress relief—modulates autonomic output and cardiovascular stability. https://onlinelibrary.wiley.com/doi/10.1111/psyp.70235

3. Autonomic recovery following submaximal exercise in yoga practitioners versus aerobic and strength-trained individuals

Authors: Sreenath N., Pallavi L. C., Baskaran Chandrasekaran, Lavya Shetty, Lavina M. Manu & Shivaprakash Gangachannaiah

Journal: Annals of Physical and Rehabilitation Medicine

This comparative study assessed autonomic recovery speeds following submaximal exercise across three distinct groups: yoga practitioners, aerobic athletes, and strength-trained individuals. The results suggest that long-term yoga practice may confer a unique advantage in parasympathetic reactivation and in the speed of autonomic recovery post-exertion compared to traditional aerobic or resistance training backgrounds. https://www.tandfonline.com/doi/full/10.1080/07853890.2026.2615509

4. The interplay between cardiac and brain activities within a balancing skill-challenge context during goal-directed motor control

Authors: Heng Gu, Qunli Yao, Chao Yang, Zhaohuan Ding, Xiaoli Li & He Chen

Journal: Cerebral CortexGetty Images

Focusing on the brain-heart axis, this study explores the synchronization between cardiac rhythms and cortical activity during goal-directed motor control tasks requiring balance. The researchers id...

This Week in HRV - Episode 21

In this episode of This Week in HRV, Matt Bennett explores five recent studies that deepen our understanding of heart rate variability as a marker of autonomic regulation across endocrine health, sleep physiology, theoretical neuroscience, extreme environmental exposure, and performance nutrition. Together, these studies illustrate how HRV reflects the nervous system’s capacity to integrate hormonal, behavioral, environmental, and recovery-related demands.

1. Comparative Analysis of Heart Rate Variability in Women with and Without Polycystic Ovary Syndrome (PCOS)

Authors: Sivaranjani; Prabhavathi; Keerthi; Bhavisha Sreenivasan; Thamarai Selvi; Saravanan; Panneerselvam
Journal: Journal of Pharmacy and Bioallied Sciences

This study examined resting heart rate variability in women with and without PCOS. Women with PCOS showed reduced HRV, reflecting diminished parasympathetic modulation and altered autonomic balance. The findings suggest that autonomic dysregulation may be present early in PCOS, even before overt cardiovascular disease develops.

https://journals.lww.com/jpbs/fulltext/2025/10000/comparative_analysis_of_heart_rate_variability_in.9.aspx

2. Autonomic Characteristics of Periodic Limb Movements: Comparison of Whole-Night and Stage N2 Linear and Non-Linear Heart Rate Variability

Authors: Elif Simin; Selahattin; Elif Göksu
Journal: Clinical Autonomic Research

Using overnight polysomnography, this study analyzed how periodic limb movements during sleep affect autonomic regulation. HRV analysis revealed transient sympathetic activation during limb movement events and reduced autonomic complexity across the night.

https://link.springer.com/article/10.1007/s10286-025-01184-y

3. Biofeedback from the Free Energy Principle Perspective: Some Psychoeducational and Clinical Implications

Author: Yossi
Journal: Biofeedback

This theoretical paper applies the Free Energy Principle to biofeedback practice, framing HRV biofeedback as a process of reducing physiological uncertainty and improving adaptive regulation.

https://biofeedback.kglmeridian.com/view/journals/biof/53/3/article-p47.xml

4. Autonomic Regulation across Sleep and Wake during an Antarctic Overwintering

Authors: C. Tortello; A. Folgueira; B. Cauda; L. E. González; E. Sala Lozano; N. Pattyn; G. Simonelli; S. A. Plano; D. E. Vigo
Journal: Scientific Reports

This study tracked heart rate variability across months in individuals overwintering in Antarctica, showing reduced parasympathetic activity, weakened circadian organization, and diminished sleep–wake autonomic differentiation during prolonged isolation.

https://www.nature.com/articles/s41598-025-31009-x

5. The Effects of an Acute Dose of Cannabidiol on Health and Two-Mile Time Trial Performance—A Pilot Study

Authors: Elyssa R., Brandon, Seth M., and Laura K.
Journal: Nutrients

This pilot study examined the effects of an acute cannabidiol dose on endurance performance and physiological markers. While performance did not improve, changes in autonomic recovery markers suggest CBD...

This Week in HRV 

In this episode of This Week in HRV, Matt Bennett explores five recent studies that deepen our understanding of heart rate variability across time, technology, cardiovascular health, brain aging, and addiction recovery. Together, these papers highlight both the strengths and limitations of HRV as a window into nervous system regulation.

1. Unveiling the Extremely Low Frequency Component of Heart Rate Variability

Authors: Krzysztof, Adam G.
Journal: Applied Sciences

This study demonstrates that ultra-low-frequency HRV is not a single physiological process, but can be decomposed into two independent components reflecting circadian and ultradian rhythms. The findings expand our understanding of long-term autonomic regulation and biological timing.

https://www.mdpi.com/2076-3417/16/1/426

2. Limited Evidence for Heart Rate Variability as a Predictor of Cognitive and Pathophysiological Brain Markers

Authors: Sofia, Jaime D., Arie, Balewgizie, Harriëtte, Rozemarijn, Rudi, Ronald, Peter Paul
Journal: Journal of Alzheimer’s Disease

Using a long-term longitudinal design, this study examined whether midlife HRV predicts later cognitive performance, brain imaging findings, or Alzheimer’s biomarkers. Results suggest HRV alone is not a reliable early predictor of neurodegenerative pathology.

https://journals.sagepub.com/doi/10.1177/13872877251409343

3. Beyond Motion Artifacts: Optimizing PPG Preprocessing for Accurate Pulse Rate Variability Estimation

Authors: Yuna, Natasha, Aarti, Varun, Matthew S.
Conference Proceedings: ACM (UbiComp)

This engineering study shows that preprocessing choices—particularly band-pass filtering—strongly influence the accuracy of pulse-rate variability derived from wearable PPG sensors. The authors demonstrate that adaptive preprocessing significantly improves HRV estimation accuracy.

https://dl.acm.org/doi/epdf/10.1145/3714394.3756241

4. Association of Diurnal Blood Pressure Patterns with Heart Rate Variability and Retinopathy in Patients with Essential Hypertension

Authors: Fengping, Hui, Tianfeng, Chen
Journal: Scientific Reports

This clinical study links abnormal nighttime blood pressure patterns with reduced HRV and a markedly higher prevalence of hypertensive retinopathy. The findings highlight the relationship between circadian autonomic regulation and microvascular health.

https://www.nature.com/articles/s41598-025-29694-9

5. Yoga for Opioid Withdrawal and Autonomic Regulation: A Randomized Clinical Trial

Authors: Suddala, Hemant, Bharath, Jayant, Ravindra P., Nishitha, Venkata Lakshmi, Urvakhsh Meherwan, Shivarama, Ganesan, Prabhat, Bangalore Nanjundiah, Kevin P., Matcheri, Pratima
Journal: JAMA Psychiatry

This randomized clinical trial shows that adding yoga to standard opioid detoxification significantly accelerates withdrawal recovery, improves HRV, reduces anxiety, improves sleep, and decreases pain—demonstrating the role of autonomic regulation in addiction recovery.

https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2843424

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In this episode, Matt Bennett is joined by Dr. Inna Khazan and Dr. Mara Mather to discuss Dr. Mather's research on heart rate variability biofeedback. Dr. Mather's work opens exciting new insights to the real and potential power of HRV biofeedback.