HRV has become one of the most talked-about metrics in health and performance, but it’s also one of the most misunderstood. In this episode, we sit down with Dr Marco Altini, data scientist, endurance coach, and founder of HRV4Training, to explore what heart rate variability actually reflects in the body, and how it should (and shouldn’t) be used. With a background spanning data science, physiology, and wearable technology, Marco brings a unique perspective on how physiological data can inform stress, recovery, and long-term adaptation. His work has influenced elite athletes, coaches, and increasingly, how HRV is applied in general health and longevity. We break down the foundations of HRV, how it relates to the autonomic nervous system, and whether it should be viewed as a marker of recovery, resilience, or overall system health. A key focus of the conversation is interpretation. Marco explains why “higher HRV is always better” is a flawed concept, the importance of understanding your individual baseline, and why daily fluctuations often matter far less than long-term trends. We also explore the role of wearable technology — from ECG to PPG devices — and whether consumer tools are now accurate enough to guide decision-making. As an advisor to Oura, Marco shares insight into how these technologies are evolving, and the risks of oversimplifying complex physiology into single scores. Finally, we discuss the practical side: what actually impacts HRV, how lifestyle factors like sleep, stress, and alcohol influence your data, and how to use HRV in a way that genuinely supports healthspan and performance. 🎙️ In This Episode, We Cover What HRV actually measures in the bodyHRV and the autonomic nervous systemHRV as a marker of health, resilience, and longevityWhy “higher HRV is better” is misleadingThe importance of baseline, normal range, and trendsDaily vs long-term HRV: what really mattersCommon mistakes when interpreting HRV dataWhich metrics are actually useful (and which aren’t)Wearables explained: ECG vs PPG vs camera-basedAre consumer devices accurate enough?Morning vs overnight HRV trackingHow sleep, stress, and alcohol impact HRVCan you meaningfully improve your HRV?The risks of over-relying on wearable dataPractical ways to use HRV for health and performance 🎯 Who This Episode Is For • Anyone using or considering wearable health technology • People interested in recovery, stress, and longevity • Athletes and coaches using HRV for performance • Individuals looking to better understand their physiology • Clinicians and practitioners interested in data-driven health 🎙️ Powered by Mayfair Health At Mayfair Health, we specialise in recovery, performance, and proactive wellness. If you’re navigating ongoing symptoms, optimising your health, or looking to better understand your body, our multidisciplinary team is here to help. 🔗 Website: https://www.mayfairhealth.co.uk 📩 Contact: info@mayfairhealth.co.uk 📞 Phone: 020 3985 1500 📱 Instagram: @mayfairhealth