If you've been a long-time podcast listener, then you're no doubt familiar with Dr. Jay T. Wiles, my jolly sidekick on the regular Ben Greenfield Fitness Q&A podcast episodes. What you may not know about Dr. Wiles is that he is a true expert in all things heart rate variability (HRV) testing, tracking, and interpretation; and in this podcast episode, he takes a deep dive into how to use HRV to optimize your recovery, performance, sleep, stress, and nervous system. Dr. Wiles is a clinical health psychologist with a passion for helping others reach their full potential from an integrative and holistic perspective. With this strong passion for integrative and holistic care, especially in nutrition and psychophysiology, Dr. Wiles completed his doctor of clinical psychology degree at Regent University with a specialized focus and concentration in health psychology. Dr. Wiles then furthered this specialty in health psychology as a pre-doctoral intern at McGuire VA Medical Center in Richmond, VA and post-doctoral fellowship at WJB Dorn VA Medical Center in Columbia, SC. He currently works as a health psychologist for the Department of Veteran Affairs. With specialized training in health behavior coaching, health assessment, nutritional interventions for mental and physical health, motivational interviewing, applied psychophysiology (biofeedback and neurofeedback) and consultation, Dr. Wiles works as a consultant for companies, organizations, practitioners, and individual patients on nutritional psychology, health behavior change, applied psychophysiology, and health promotion/disease prevention via complementary and integrative practices. He is also board certified in biofeedback and heart rate variability biofeedback as well as board-certified in Tai Chi for rehabilitation. Dr. Wiles has worked closely with elite athletes and executives on enhancing peak performance through his online consulting agency, . This consulting agency focuses solely on training and regulating psychophysiology for performance. ​He is passionate about education and consultation with patients and organizations in an effort to increase health outcomes through focusing on prevention and well-being, as opposed to disease and symptom mitigation. During this solosode with Dr. Jay, you'll discover: -Jay's background and a brief overview of "biofeedback"...7:16 Biofeedback: the use of your physiology to enhance self-awareness in order to promote self-regulation Like learning an instrument: perform an action, observe the results, repeat until the desired result has been met HRV is the most fundamental building block of biofeedback -Research on the use of HRV as a metric and HRV Biofeedback...11:43 Wellness, Performance, Recovery, and Mental Well-being Robust research on HRV began only 20-30 years ago HRV is linked to heart attacks, strokes, physical performance Optimized recovery, sleep, homeostasis of nervous system, and much more... Higher stress (real or perceived) resulted in lower HRV scores -Overview of Psychophysiology...18:46 Central Nervous System and Peripheral Nervous System Autonomic Nervous System Parasympathetic Versus the Sympathetic Response Autonomic Balance Baroreflex Response Acetylcholine Response Book: by Robert Sapolsky -What Is Heart Rate Variability...39:55 PPG vs. ECG Metric of resiliency to change Sources of HRV Respiratory Sinus Arrhythmia (RSA) Autonomic Balance -Metrics of Heart Rate Variability...49:19 Defining different domains Time domain SDNN RMSSD HR Max-HR Min or heart rate amplitude Frequency Domain ULF VLF LF/HF Ratio -HRV Norms...1:12:00 Defining Norm-based HRV comparisons High vs. Low HRV Values for all norms found in 21,000 participants Norm vs. Individual baseline comparisons -HRV Training/Regulation...1:23:45 Resonance Frequency Training Effortless, low and slow, diaphragmatic breathing style breathing (Book: ) Use of Wearable technology for biofeedback Pros and Cons Different Devic