Timestamp * 1:00 - Background and Sports Journey: Dr. Altini shares his academic journey in computer science, engineering, and data science, alongside his personal transition into endurance sports. * 3:31 - Defining HRV and How It Differs from Heart Rate: Understanding HRV as the variation in time between consecutive heartbeats, which reflects the autonomic nervous system's response to stress. * 8:10 - Clarifying Common HRV Myths: Dr. Altini dispels misconceptions such as the importance of absolute HRV values and the notion that higher HRV is always better. * 11:40 - Making the Case for HRV: Despite limitations, HRV provides unique insights into the body's stress response, which can inform training and lifestyle adjustments. * 14:10 - HRV in Free-Living Analysis: Large-scale research reveals that HRV is a more sensitive marker of stress than resting heart rate, and different stressors elicit varying physiological responses. * 18:45 - Validating Smartphone-Based HRV Measurement: Dr. Altini discusses how the HRV4Training app, using smartphone cameras, was proven to be as accurate as chest straps and ECGs. * 21:55 - Practical HRV Monitoring with HRV4Training: The app helps athletes accurately measure HRV, providing actionable insights based solely on physiological data while allowing users to add context manually. * 26:10 - Unique Features of HRV4Training: The app's focus on raw physiological data offers a clear distinction from competitors, who often combine behavioral data to produce composite scores. * 32:50 - HRV in Night vs. Morning Measurements: Dr. Altini elaborates on the differences between night and morning measurements and how HRV trends vary due to circadian rhythms and sleep stages. * 38:40 - HRV and Sleep Tracking Limitations: Despite advancements, wearable devices often lack accuracy in estimating sleep stages, emphasizing the importance of skepticism. * 43:30 - Spot Check vs. Continuous Monitoring: Dr. Altini warns against overinterpreting continuous HRV monitoring due to potential misinterpretation of data, recommending periodic spot checks instead. * 46:00 - HRV-Guided Training: Dr. Altini explains how to implement HRV-guided training by adjusting intensity based on daily HRV measurements relative to one's normal range. * 51:00 - HRV for Individual Athletes and Golfers: Coaches and individual athletes can use HRV trends over multiple tournaments and travel periods to identify patterns and refine performance strategies. * 55:20 - Advice for Golfers Considering HRV Monitoring: Golfers can use HRV to manage travel stress, tournament phases, and performance consistency by identifying patterns in their physiological responses. * 58:00 - Current Projects and Future Directions: Dr. Altini aims to improve communication around HRV while working on refining personalized feedback loops to optimize health and performance. * 1:03:00 - Book Recommendations and Influences: Dr. Altini recommends Suggestible You by Erik Vance, highlighting its insights into the placebo effect and psychological influences on performance Resources Book Recommendation #1: Suggestible You: The Curious Science of Your Brain's Ability to Deceive, Transform, and Heal Book Chapter: How Data Can Capture Recovery: The Case for Heart Rate Variability Paper #1: What Is behind Changes in Resting Heart Rate and Heart Rate Variability? A Large-Scale Analysis of Longitudinal Measurements Acquired in Free-Living Paper #2: Comparison of Heart-Rate-Variability Recording With Smartphone Photoplethysmography, Polar H7 Chest Strap, and Electrocardiography Paper #3: State of the science and recommendations for using wearable technology in sleep and circadian research HRV4Training: https://www.hrv4training.com/ Personal Substack: marcoaltini.substack.com HRV4Training Substack: hrv4training.substack.com Twitter/X: https://twitter.com/altini_marco About Dr. Marco Altini Dr. Marco Altini is a scientist and developer specializing in health technology and performance, holding a Ph.D. cum laude in Data Science, an MSc cum laude in Computer Science Engineering, and an MSc cum laude in Human Movement Sciences with a focus on High-Performance Coaching. As the founder of HRV4Training, he created a pioneering mobile platform trusted by over 150,000 users, including Olympic medalists and professional teams, to monitor heart rate variability (HRV) and manage training stress. Dr. Altini also serves as a Data Science Advisor at Oura, Guest Lecturer at Vrije Universiteit Amsterdam, and Editor of the Wearable Department at IEEE Pervasive Computing Magazine. With over 10 years of experience modeling physiological data and more than 50 publications at the intersection of technology, health, and performance, he is passionate about empowering athletes and health enthusiasts to make data-informed decisions. This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit noahsachs.substack.com