Chris and Sam sat down with Marco Altini to discuss all things Heart Rate Variability. Marco holds a PhD in Data Science and two Masters of Science degrees in Computer Science Engineering and Human Movement Sciences. Marco is the founder of HRV4Training, Data Science Advisor at Oura Ring, and Guest Lecturer at VU Amsterdam. We dive into: the history behind HRV, what influences heart rate variability, the validity and reliability of different forms of measurement, wearables, interpreting data, and much more.  More about Marco:  Marco’s Twitter Marco’s Website Marco’s Substack HRV4Training --- More about us:  YouTube: https://www.youtube.com/e3rehab  Website: https://e3rehab.com/  Instagram: https://www.instagram.com/e3rehab/ Twitter: https://twitter.com/E3Rehab --- Sponsors: Minimalist Footwear: https://www.vivobarefoot.com/ (Discount code: REHAB15 for 15% off) VALD: www.vald.com --- @dr.samspinelli @dr.surdykapt @tony.comella @chrishughen --- This episode was produced by Matt Hunter.