Week 20: The Book 📖

Heart Rate Variability: Science and Strategies for Peak Performance

May 20, 2026

Hi there 👋

Excited to announce that our book is out and available for purchase from Human Kinetics’ website, here (or on Amazon).

It has been a long journey, and I am truly grateful to my coauthors for making the process genuinely enjoyable and intellectually stimulating. All of us contributed to every chapter; we learned from each other and gradually shaped a book reflecting decades of combined experience in the field.

Our goal has always been to stay between hype and skepticism, so that people can truly benefit from this tool by understanding both the potential and limitations of HRV analysis.

I hope you will enjoy the book!

Foreword
Introduction. Why This Book? Starting the Journey With HRV
What Are Our Stories With HRV?
Why Is HRV Important?
How Can This Book Help You?
Final Thoughts to Kick-Start Your HRV Reading Journey
Part I. The Science Behind HRV
Chapter 1. Physiology Foundations
Understanding the Physiological Foundations of HRV
What Is the Difference Between Heart Rate and HRV?
The Physiology of HRV
HRV Indices
Vagally Mediated HRV
Cardiac Vagal Activity and Vagal Tank Theory
The Implications of Vagal Tank Theory
Myths About HRV: Separating Fact From Fiction When Interpreting HRV
Interpreting Indices of Non–Vagally Mediated HRV
The Role of Context in HRV Interpretation
Chapter 2. Global Factors That Influence HRV
Population-Level Analyses: Understanding Individual Differences
Individual-Level Analyses: How Data Change Over Time
Environmental Stressors
Chapter 3. Impact of Sleep, Nutrition, and Hydration on HRV
Sleep and HRV
Nutrition and HRV
Hydration and HRV
Part II. Measurement and Interpretation of HRV
Chapter 4. HRV Monitoring and Tracking Tools
Common Methods and Devices for Measuring HRV
HRV Versus Pulse Rate Variability
Know Your Application: ECG Versus Photoplethysmography Versus Ballistocardiography
Protocols and Best Practices: How to Accurately Measure HRV
When to Measure HRV
Body Position: Should You Measure Lying Down, Sitting, or Standing?
Frequency of HRV Measurements
Duration of HRV Measurements
Chest Straps, Wristbands, Finger Sensors, and Phones: What Can You Use?
The Impact of Breathing on Data Collection
Artifacts in HRV Data: Movement, Ectopic Beats, and Arrhythmias
Learn to Ask the Right Questions
Chapter 5. Interpreting HRV Data
Acute Response to Training Stress and HRV
Understanding Meaningful Changes in HRV Indices: The Normal Range
Identifying Changes in HRV and What They Mean for Your Health and Fitness
Heart Rate and HRV Saturation
Physiological Adaptations to Training
Part III. Applications of HRV Monitoring
Chapter 6. Using HRV to Guide Individualized Training
Autonomic Regulation and Trainability: What HRV Can Tell Us
The Beginnings of HRV-Guided Training
State of the Art in HRV-Guided Training: The Big(ger) Picture
The Future of Individualized Training: A Combined Approach?
Expected Outcomes of HRV-Guided Training
Beyond Baseline Assessments
Chapter 7. Applying HRV in Team Settings
Devices for Monitoring HRV in Team Sports
The Basics of HRV in Team Sports
Challenges of Monitoring HRV in Team Sports
Chapter 8. Injury Prevention and Acute Recovery
Using HRV Monitoring to Detect Early Signs of Overtraining and Injury
HRV-Guided Training for Injury Prevention
HRV-Guided Training for Injury Rehabilitation
HRV for the Management of Brain Injuries and Concussions
Chapter 9. Health, Disease Prevention, and Longevity
The Role of Autonomic Function in Health and Disease
HRV and Fundamental Health Mechanisms
The Role of HRV in Disease Prevention and Management
Improving Health Outcomes With HRV Monitoring
Part IV. The Brain’s Impact on HRV
Chapter 10. HRV and Cognitive Function
HRV, Mental Performance, and Function
Brain Structure and HRV
The Prefrontal Cortex, Executive Function, and HRV
Measuring HRV for Cognitive Performance
Physical Activity and HRV
HRV and Mental Fatigue
Collecting HRV Data to Manage Mental Fatigue and Improve Cognitive Functioning
Strategies for Overcoming Mental Fatigue and Improving Executive Performance
Chapter 11. Managing Psychological Stress
Understanding Psychological Stress
Strategies for Using HRV to Manage Psychological Stress
Burnout and HRV
Challenges and Limitations of Monitoring HRV to Manage Psychological Stress
Chapter 12. HRV and Mental Training
Psychological Skills: The Foundations
Breathing Techniques
Mind–Body Relaxation
The Low HRV Autopilot
Inspirational Techniques
Self-Reflection
Connection Matters: The Power of Social Support for HRV
Part V. Maximizing Daily HRV Monitoring for Athletic Performance
Chapter 13. Your Daily HRV Routine
The Ease of Capturing HRV Data
What Could Your HRV Day Look Like?
HRV Analysis Before and After Exercise
What About Continuous HRV Monitoring?
Chapter 14. A 30-Day HRV Training Plan
Why Complete an HRV Challenge?
Your HRV-Supporting Morning Routine
Your HRV-Supporting Evening Routine
Building Blocks for HRV Awareness and Improvement
The 30-Day HRV Challenge
What to Do After the 30-Day HRV Challenge
Epilogue. Your HRV Journey Is Just Starting
Summary of Key Takeaways
Personal Growth and Continuous Learning
Start Simple and Build a Solid Foundation
HRV for Athletic Training and Performance
Interpreting Data and Making Training Decisions
Overview of HRV Applications Across Sports
Sharing Your HRV Journey

Personal Coaching for Runners

Please apply here should you be interested in working with me.

You can also learn more about my coaching, here.

Thank you!

HRV4Training Pro

HRV4Training Pro is the ultimate platform to help you analyze and interpret your physiological data, for individuals and teams.

You can find a guide and overview here.

Try HRV4Training Pro for free at HRVTraining.web.app

When using Pro, the app will also automatically recognize your account and add the Normal Range to the Baseline view, together with detected trends and additional annotations, which can help contextualizing longer-term changes.

You will also be able to pick rMSSD as the parameter to see on the homepage of the app.

You can enable the normal range in the Baseline view by logging in in HRV4Training Pro, here. The app will update automatically.

Thank you again for your support and for allowing us to remain independent.

See you next week!

Marco holds a PhD cum laude in applied machine learning, a M.Sc. cum laude in computer science engineering, and a M.Sc. cum laude in human movement sciences and high-performance coaching. He is a certified Ultrarunning Coach.

Marco has published more than 50 papers and patents at the intersection between physiology, health, technology, and human performance.

He is co-founder of HRV4Training, Endurance Coach at Destination Unknown, advisor at Oura, guest lecturer at VU Amsterdam, and editor for IEEE Pervasive Computing Magazine. He loves running.

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