Welcome to Season 2 of Trail & Error. This week’s guest is Dr. Marco Altini. Marco has a PhD in Data Science and Masters degrees in Computer engineering, Human Movement Science and High-Performance Coaching. He is Data Science Advisor at Oura (the wearable sleep rings) and the founder of HRV4Training app. He’s also a passionate runner, based in Amsterdam. On this episode we uncover what heart rate variability is, how it affects performance and adaptation, what lifestyle variables impact HRV, continuous glucose monitoring and what it might mean for the sport of running, and even more geeky stuff besides that.