Australian HRV researcher Dr. James Heathers (pictured above) is one interesting dude. On a professional level, he is a Ph.D and an Endeavour Research Fellow in Electrocardiology at Poznan University of Medical Science, where his research revolves around measurement issues in heart rate and heart rate variability. On another level, he has , where he writes about health, science, medicine and bioethics, and has articles on topics such as medical sensors embedded in tattoos, how drinking affects sleep quality, how peptides are used for doping by professional athletes, and much more. In our discussion in this podcast, James and I take a deep dive into HRV, and our topics include: -How James went from being an experimental psychologist to instead being immersed in HRV research... -Very interesting ways to use HRV that tend to fly under the radar, including computer gaming and cognitive performance enhancement... -Whether HRV can really measure the things that the self-quantification industry often claims it can measure (e.g. sympathetic outflow, or blood lactate, or ‘readiness’)... -When a high HRV may not be a good thing... -Which supplements and medication affect HRV... -The main areas of research in HRV now that James is most excited about, including something called HRR and breathing ladders... -And much more! Warning: if you know nothing at all about HRV, you will probably need a good intro to HRV prior to listening in, because this particular podcast is a bit more advanced, and skips over the basics of HRV. The good news is that there is over three years of HRV articles and podcasts on BenGreenfieldFitness.com, and here are the most popular and useful: – (podcast) – (podcast) – (podcast) – (article) – (article) Other resources we discuss during this episode: - - - - (a second-generation research grade ECG machine that you can buy for a few hundred dollars) - (Samsung has released a research platform for developers called Simband, who can now use the platform to build their own software applications without having to build their own hardware) - (a lab at MIT developed a method of pulling your heart rate straight out of a webcam picture) - Do you have questions, comments or feedback on HRV? Leave your thoughts at  and either myself or James will reply.