Marco Altini, has a PhD in Data Science and an MSc in Human Movement Sciences and High-Performance Coaching. He is the founder of HRV4Training and a passionate runner. In this interview, we discuss the latest in research and application when it comes to heart rate variability (HRV). IN THIS EPISODE YOU'LL LEARN ABOUT: -A brief summary of what HRV is and the benefits of monitoring it -What are the most important factors that influence HRV and resting heart rate (RHR), and what are their relative importance or magnitude? Based on Marco's large-scale, free-living study published in late 2021.  -Chest strap or phone camera measurement of HRV: what are the differences?  -Should you measure in the morning, or use a tool that allows you to measure HRV all night (and day)?  -How to use and interpret HRV and RHR - why and when to rely on one or the other -The current state of evidence when it comes to "HRV-guided training"  SHOWNOTES: https://scientifictriathlon.com/tts325/ SCIENTIFIC TRIATHLON AND THAT TRIATHLON SHOW WEBPAGE: www.scientifictriathlon.com/podcast/ SPONSORS: ROKA - Exceptional quality triathlon wetsuits, trisuits, swimskins, goggles, performance sunglasses as well as prescription eyeglasses and sunglasses.  Online vision test for prescription updates and home try-on options available for eyeglasses. Ships from  the US, UK and EU. Trusted by world-leading athletes such as  Lucy Charles-Barclay, Javier Gómez Noya, Flora Duffy, Morgan Pearson, Summer Rappaport and others in triathlon, cycling, speed skating, and many more. Visit roka.com/tts for 20% off your order.   ZEN8 - The ZEN8 Indoor Swim Trainer is a one of a kind swim bench for time-crunched triathletes looking to improve their swim technique, power and propulsion, and consistency of swim training. It is very affordable, about the price of a pair of running shoes, and Zen8 offer free shipping in the US and the UK. Best of all, you can try it risk-free. If you don't love it after two weeks, send it back and get a full refund. Get 20% off your order at zen8swimtrainer.com/tts. LINKS AND RESOURCES: Marco's website, Medium blog, Instagram, Twitter and Research Gate HRV4Training website and Instagram Heart Rate Variability (HRV) – Applications and Insights in 2018 and Beyond with Marco Altini | EP#144 What Is behind Changes in Resting Heart Rate and Heart Rate Variability? A Large-Scale Analysis of Longitudinal Measurements Acquired in Free-Living - Altini and Plews 2021 RATE AND REVIEW: If you enjoy the show, please help me out by subscribing, rating and reviewing: www.scientifictriathlon.com/rate/ CONTACT: Want to send feedback, questions or just chat? Email me at mikael@scientifictriathlon.com or connect on Instagram, Facebook, or Twitter.